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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Separation Gamma Equ
      #5777010 - 04/04/13 05:06 AM

This double is one of the test pairs of the Sissy Haas' project and listed here with 1.5" separation and magnitudes of +4.7/8.7mag. In the WDS catalogue this pair is listed with 1" separation (WDS21103+1008, KNT5, RA 21:10:20.5 Dec +10:07:55) and Hipparco lists this pair as HIP 10452 with 1.3" separation.
If the WDS data is correct then this pair would be hard to split with 180mm aperture, if the 1.5" from Sissy are correct, then this could be under perfect conditions possible for 120mm aperture.
Gam Equ is below the horizon for me now so I cannot check it myself - for my 140mm refractor this would be the difference between (speaking in terms of Chris Lord's Rule of Thumb according to the implementation in the AstroPlanner software) "unresolvable" and "extremely difficult" (but certainly doable).
Had anybody recently observed Gam Equ or has this possibility now?
Wilfried


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: WRAK]
      #5777210 - 04/04/13 09:23 AM

Wilfried, we had a discussion of this one last year - August/September - thread is under "Is Gamma Equuleus closing". Read through that. I'm hoping that later this year we can get further attempts to split this one, but I suspect it's out of reach for most of us now.

Conclusion I suggested is that it's moved fairly quickly since the last listed measure and is now too close for mid-size scopes. I'd therefore suggest the claims to split it recently with moderate apertures (eg 180mm) might prove to be spurious resolution.

Essentially what's needed is a new measure, preferably from a large telescope using adaptive optics (speckle is unlikely given the large delta-m). That way we can know what the present level of difficulty is likely to be, and what size telescope might be the minimum now needed for resolution. It's definitely closer than it was.


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ new [Re: fred1871]
      #5777869 - 04/04/13 02:34 PM

Fred, thanks - I somehow remembered this thread but could not locate it. This topic popped up for me again because there are positive splits recorded in the Haas project for Gam Equ on the border of possibility for 1.5" (still the "offical" data for the Haas project) with 120mm and for 1" with 178mm (but without central obstruction and I assume for the 178mm 26% CO so ...).
According to the repeatet non split with a 24" scope mentioned in the thread you referred to then even the further reported split with 200mm would be a false positive.
Wilfried


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ new [Re: WRAK]
      #5778179 - 04/04/13 05:25 PM

Unless I was looking at the wrong star I split this one late last autumn with my 6" Apo at around 300x. It surely was above 1" and although a difficult one for the delta, it was doable over several nights. I am not an experienced observer like you lot but I didn't have a problem splitting this one...
I use a go-to mount and SkySafari Pro on my iPad,so location wise I was pretty certain I was looking at the right one.

Beautiful pair by the way!


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ new [Re: R Botero]
      #5778949 - 04/05/13 03:21 AM

Had a look in my own observation log - tried Gam Equ mid November last year and failed due to not so good conditions (high humidity with NEML +2.5mag, jumping diffraction pattern) - at least I thought so.
The advertised data for doubles in SkySafari amazes me each time I have a look at it. I once sent an inquiry to the SkySafari support for their source but got never an answer. For Gam Equ Sky Safari shows 1.4" +4.71/8.21mag - I have no idea where this data might come from. But this would certainly indicate an easy split with 6" and a good chance with my 5.5".
Wilfried


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ new [Re: WRAK]
      #5778976 - 04/05/13 04:19 AM

Hi Wilfried

Yes, I don't know where SkySafari gets its data for doubles but they certainly pride themselves in how accurate their satellite, comet and asteroid data is. They claim they are the only software company out there taking into account gravitational perturbations to calculate comet and asteroid positions (to "NASA-like precision")...but that doesn't say much about doubles. Maybe they have gone as long as including orbital data in their doubles and precessing them to accommodate epoch change? - And maybe those orbital models are out?

In any case, I'm pretty sure I was looking at Gamma Equulei and I split it with my 6" refractor last November.

Roberto


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5778977 - 04/05/13 04:20 AM

I'll ask the question about doubles in the SoutherStars Yahoo Group now. I have sent emails to their support address but find that I get answers faster in the Yahoo group where the developers are very active. I'll revert back with any info I get.
Roberto


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ new [Re: R Botero]
      #5778987 - 04/05/13 04:44 AM

I found this relatively new (2010) academic paper ( 5 Equ )on the properties of the main star in the 5 Equ system in a search in the Los Alamos Lab online archive. The paper deals mostly with its magnetic properties - as 5 Equ is one of the brightest stars with high frequency magnetic field changes visible in the sky. It lists its current multiple system separation as 1.25" +- 0.04" citing another paper of 2002.
If that is indeed the separation, it should be easily visible with a 5-6" instrument under good conditions.

What do you think?


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ new [Re: R Botero]
      #5779080 - 04/05/13 08:02 AM

Roberto, very interesting paper, thanks. The current WDS data with 1" is also from a 2002 observation, curious.
With 1.25" separation this would be already rather difficult with a 6" scope (Lord rating "XD" = eXceedingly Difficult even with perfect seeing). My current RoT model gives for 1.25" separation 176mm aperture for a 50% split probability - 150mm would then have a chance of about 5% for a split. Your observation report with repeated splits over several nights indicates no difficulties with 150mm so this would speak rather for a 1.5" separation.
Wilfried


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: R Botero]
      #5779090 - 04/05/13 08:11 AM

Quote:

I found this relatively new (2010) academic paper ( 5 Equ )on the properties of the main star in the 5 Equ system in a search in the Los Alamos Lab online archive. The paper deals mostly with its magnetic properties - as 5 Equ is one of the brightest stars with high frequency magnetic field changes visible in the sky. It lists its current multiple system separation as 1.25" +- 0.04" citing another paper of 2002.
If that is indeed the separation, it should be easily visible with a 5-6" instrument under good conditions.

What do you think?




Roberto, the comment "should be easily visible with a 5-6" instrument under good conditions" gives me the impression you're expecting the pair to be splittable according to the Dawes Limit numbers or nearly so - but if you read through the previous thread I reminded Wilfried of, you'll see that the brightness difference of the A and B stars of Gamma Equulei is 4.0 magnitudes - notice that the figures quoted by the WDS are modern double decimal place magnitudes. They can be expected to be of good accuracy.

Unevenly bright doubles are more difficult than near-even pairs. Once you have 4 magnitudes difference they're much more difficult. It means star A is 40 times as bright as star B.

Note the details I and others gave in discussing the pair in the earlier thread. The separation is now pretty definitely LESS than 1.0". It's very unlikely that a pair with the long-term record of this one will suddenly widen again in a decade, when its behaviour suggests it's moving into the closer part of the orbit and will likely close further, or at least maintain a close separation similar to 2002. I'd think the latter is less likely given the rates of change of angle in various periods.

Also, the lack of recent success in splitting with 16- and 24-inch scopes suggests continuing very close separation, probably closer than in 2002.

We can all try again observing this pair as that section of sky becomes accessible this year.

Sorry to labour some of these points, but I think further discussion does need to take into account the previous discussion and the data presented there.

The observation I quoted from Hartung's book, made back around 1960, was when the pair was likely still about 1.9" (maybe 1.8"?) and he describes it as difficult for 20cm, an 8-inch scope. Hartung was a very experienced observer and generally did very well with doubles in terms of the minimum aperture that would show them. By 2002 the pair was around half the separation of Hartung's c1960 observation.

Quite simply, from the data to hand, and failed splits by experienced observers with 16-inch and 24-inch telescopes (note the details mentioned), it's plain that Gamma Equulei is not going to be easy. Haas listed it for her project because of an older measure that happened to be the most recent in the WDS listing at a particular time. The 2002 measure wasn't published in 2002, so it didn't get into the WDS until after the version Haas used.

What's needed now is
1. a new measure
2. observations by experienced observers with good telescopes of reasonable size under very good seeing conditions

no 1. will give us a good idea of the current state of this binary
no 2. can establish what size scope is needed for splitting a fairly bright 4-magnitude-delta-m pair at very close separation


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ new [Re: WRAK]
      #5779240 - 04/05/13 09:43 AM

Wilfried
If what I saw was 5 Equ, I observed it over two consecutive nights in late November last year (don't have my notes at hand) and clearly split it the first night and "knew what to look for" the second. After that, the weather took a turn for the worse and it became inaccessible from my backyard.
This is indeed a puzzling double! I look forward to it becoming visible again! I'm happy to stand corrected but would like to have seen it with the 6" Apo
Thanks
Roberto


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ new [Re: fred1871]
      #5779303 - 04/05/13 10:23 AM

Hi Fred

My comment on "easily visible in 5-6" apertures" was way out of order and should not have been taken into the context of me dismissing your earlier thread and difficulty in observing it.
I don't agree in not taking into account the separation quoted by the academic paper though. An approved/peer reviewed scientific paper with a quoted separation carries for me a heavier probability of being correct than amateur observations like ours (particularly mine! ). Anecdotal evidence points to the two components coming closer but the rate is at best empirical from what I can read in previous threads. It could well still be in the 1.1-1.2" range.

I get the point about the magnitude differential. I was quite surprised to have been able to split it (if indeed I did so) given I have had more difficulty with other doubles of similar characteristics near that time and since.

Jim Kaler of the University of Illinois has a nice write-up on 5 Equ ( Jim Kaler ) - I think SkySafari uses his descriptions for their planetarium software.

I was trying to find a recent observation in one of the Webb Society Circulars but couldn't. I will have to take a bit more time to do this. I've also been looking for an orbital model but most papers centre around the rotational period of this star (a whopping 70+ years!) and/or its magnetic properties.

As you say the only way of settling this is for us to wait for the Little Horse to rise! As I said to Wilfried, I'm happy to stand corrected if I cannot split it this time around!

Roberto


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7331Peg
Sirius Observer
*****

Reged: 09/01/08

Loc: North coast of Oregon
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5779662 - 04/05/13 01:48 PM

I don't know where Sky Safari gets its double star data, either, but at times it's atrociously poor. It's not something to be relied on at all.

Otherwise, the data in it for stars (such as distance and spectral class) seems to be rather accurate.

Hope you get an answer on the Yahoo group -- a lot of people depend on Sky Safari, so whatever the bug is, it needs to be corrected.


John


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ - SkySafari data new [Re: 7331Peg]
      #5780213 - 04/05/13 05:32 PM

No answer on that group yet...

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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: R Botero]
      #5780353 - 04/05/13 07:05 PM

The paper referred to is 2010, before the publication of the 2002 measure, which was in the Monthly Notices of the RAS in 2011.

The measure referred to in the 2010 paper is quoted from a 2002 paper (Fabricius et al), and we'd need to know what date that measure was made as the double has been changing.

The data I used was the complete data set obtained from the US Naval Observatory last year, and which included the 2002 measure. Unfortunately, that 2002 figure appears to be the most recent currently available. That's why I'm hoping for a new measure, preferably with a very large scope and adaptive optics to ensure high accuracy.


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: fred1871]
      #5780875 - 04/05/13 11:26 PM

The paper on "5 Equ" referred to quotes a PA of around 265 for the pair - that's the clue that it's an older measure, as the PA has been decreasing over time.

PA for 1867 was 277; for 2002, 258. So 265 is fairly late (rate of change is faster later) but definitely earlier than 2002 by some years.

I'm away from home this weekend so I don't have all my data files with me, to provide a basis for a more detailed commentary.

Looking at the WDS online today, the 2002 measure is still the most recent. Annoyingly, the wide C and D stars were re-measured in 2011, but not AB. Does this suggest AB was too close for whatever was used for C and D? Without the full data files and their sources that's only a hypothetical possibility.


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5781047 - 04/06/13 02:24 AM

Input from the SkySafari Yahoo Group and one of the developers of SkySafari Pro:

"Gents,

Welcome to the world of astronomical data catalogs, where everything is precise to 18 digits, and every source is in complete disagreement with every other source :-)

FWIW, the star catalogs we use are listed here:

http://www.southernstars.com/support/resources/stars.html

Our basic stellar database is NASA SkyMap + Hipparcos + Tycho, plus GSC 1.3 in the Pro version.

For those stars in the above catalogs which have listings in the WDS, we've done our best to include separations, positions angles, etc. from the latest WDS. We do not include the complete WDS, altho I will proably do this in version 4, next year.

For the roughly 2000 stars in WDS which have published orbits - and nearly all of them are included in SkySafari, since these are well-observed stars with entries in Tycho/Hipparcos - SkySafari uses the published orbit to compute angular separation and position angle "live". You can use Sirius or Alpha Centauri as an example. Their PA/Separation will change as the years go by. You can also animate the motion year-over-year and watch the components move in the sky chart.

That's about the best we can do for now. There will not be any major rewrites of the database until SkySafari 4, next year.

-Tim"


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5781151 - 04/06/13 05:01 AM

OK, thanks for providing this info. So SkySafari offers now regarding double stars a mixture or sometimes very precise and otherwise relative unreliable data - until SkySafari 4 it seems then better not to rely on SkySafari for doubles but always to check with WDS.
Wilfried


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5781318 - 04/06/13 09:02 AM

Sounds interesting regarding their intentions for SkySafari, but Wilfried has given an accurate description of their current (mixed) state.

Incidentally - "For the roughly 2000 stars in WDS which have published orbits - and nearly all of them are included in SkySafari, since these are well-observed stars with entries in Tycho/Hipparcos - SkySafari uses the published orbit to compute angular separation and position angle "live"."
I hope this will NOT include binaries with grade 5 orbits - as orbits so graded in the 6th orbit catalog are generally far too preliminary - uncertain - to be useful for ephemerides. Some grade 5 orbits are best treated as "premature".


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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5781432 - 04/06/13 10:27 AM

"We do not include the complete WDS, altho I will proably do this in version 4, next year."

This possibility intrigues me greatly. Imagine having this resource available at the telescope while observing. And for making observing lists!

As for the statistics/data we already know that there is some variation in the published numbers as we have seen in the case of Gamma Equ. Sky Safari can only put one set of Sep. and PA for each double so, no matter which one they choose, they will be "wrong". I'd rather not criticize them for this.

The 'live orbits' is an excellent resource. (even for grade 5 orbits if we don't try to go more than 10 or so years into the future by which time Sky Safari will have better orbital elements as they come available...)

Dave


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7331Peg
Sirius Observer
*****

Reged: 09/01/08

Loc: North coast of Oregon
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5782000 - 04/06/13 02:40 PM

I've seen that response before on the Sky Safari double star problem, but that really doesn't address the problem. Granted, there are discrepancies between various catalogues, depending on dates of observations, minor differences in measurements, and just plain human error.

But I've run into more than a few cases where the separation and distance info in Sky Safari is just plain way off.

For example, here's one I just came across:

Tau Ursae Majoris -- Sky Safari shows a separation of 0.0" with a PA of 311 degrees. It's actually a triple star, with the WDS showing AB at 52.80" and 37 degrees (2003) and AC at 102.60" at six degrees (1991).

I wish now I had made a list of others, but I've just quit using it as a double star reference. Otherwise, it's really a great little tool.

At any rate, the best advice until this kind of thing is corrected is to stay with the WDS or StelleDoppie sites.


John


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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Re: Separation Gamma Equ - SkySafari data new [Re: 7331Peg]
      #5782381 - 04/06/13 06:41 PM

John, I find Sky Safari superb for finding doubles, making observing lists and for pointing my scopes to them. I use the WDS for any empirical data I need.

Dave


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7331Peg
Sirius Observer
*****

Reged: 09/01/08

Loc: North coast of Oregon
Re: Separation Gamma Equ - SkySafari data new [Re: Cotts]
      #5782955 - 04/07/13 12:36 AM

I agree, it has all those strengths. Don't misunderstand me, it's a great little program. I use it quite a bit, and it's a steal for what it costs. When I think of what I've paid for similar programs in the past that had nowhere near the features, I'm amazed. It's just not a reliable source for double star data at the present.

I rely on the WDS almost exclusively -- it's the ultimate source for any other program, anyway.


John


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: Separation Gamma Equ - SkySafari data new [Re: 7331Peg]
      #5783049 - 04/07/13 02:39 AM

Yes, looking forward to the full incorporation of WDS in it.

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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ - SkySafari data new [Re: R Botero]
      #5783145 - 04/07/13 05:49 AM

Another point to keep in mind when using SkySafari (certainly no bashing intended here) for double star observing is the fact that SkySafari shows only doubles included in its own database - so when you import session plans from other sources like AstroPlanner you will often end up with fewer objects than planned. But one very nice feature of SkySafari when using object lists is the marking of the objects of a selected list with a circle in the shown star map.
Wilfried


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: WRAK]
      #5841470 - 05/05/13 11:21 AM

I observed Gamma Equulei in November of 2012. The 178 mm log entry in the Haas project database is mine. It was a positive split and I stand by it. Instrument; Questar 7" Astro Barrel. Ocular; 12 mm Brandon. Magnification; x200. NELM was 4.0 or slightly better. Seeing was excellent with stable star disks showing for 30 seconds or more without a quiver. Primary; white - cream white, secondary topaz - or a rich orange yellow. I rough estimated the P.A. to be 260 degrees and the separation 1.1". The pair was well within the capabilities of the instrument. The most important factor was the steadiness of the air.

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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #5841887 - 05/05/13 03:35 PM

Bill, would certainly not question your observation report - perfect seeing enables resolutions that are otherwise impossible. Perfect seeing in terms of Pickering 9 or 10 is very rare - even in favored locations the probability is certainly in the lower single digit probability range. So the question remains how repeatable your observation is with reasonable fair to good seeing conditions most of us have also not very often but at least sometimes.
Gam Equ will come into my field of view end of September and I will try again with my 140mm refractor without much hope but also with a Mewlon 210 and if this fails also with a C925 with 235mm aperture. I have so far no double star observing experience with Cassegrain reflectors but expect at least of the Mewlon a performance equivalent to a good 180mm refractor and this should give me a fair chance for a resolution of Gam Equ with assumed 1" separation.
Wilfried


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #5842428 - 05/05/13 08:54 PM

Bill, have you read the discussion of Gamma Equulei that we had last year, August to October, under the heading "Is Gamma Equuleus closing?"?

There you'll find that various of us failed to split this double - myself with C9.25, Cotts with 6-inch apo and 16-inch Newt, Ron Price with a 24-inch Newt. Ron's notes on other pairs he did split are informative - suggesting that Gamma Equ should have been a split IF the separation was similar to older measures.

That's why your report is a puzzle, even allowing for perfect seeing conditions. The history of measures of this pair strongly suggests it's currently closing. That would be consistent with the "no-split" observations by various observers. I've provided some notes on past measures of Gamma Equ in that thread last year. I'll add further notes and analysis here if it appears likely to be useful.

Obviously, what we need to help this discussion is a new measure of the pair, after 2010 preferably and done with a large telescope for accuracy. Speckle interferometry is not practical with large-delta-m pairs - it was tried, unsuccessfully, on Gamma Equ in 1975 and 1984. Which is no doubt why the 2002 measure on a large telescope (142-inch) was done with adaptive optics. That, unfortunately, is the most recent measure currently listed - 0.96" in PA 258.


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Bill Boublitz
super member


Reged: 05/04/13

Re: Separation Gamma Equ new [Re: fred1871]
      #5842745 - 05/06/13 12:24 AM

Yes Fred, I read the discussion. That's why I posted my observation. I do not feel privileged to comment on others experiences or equipment; only to read and note them with interest. I urge you to continue looking. Good wishes ~ Bill

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inZet
member


Reged: 02/12/09

Loc: Milan, Italy
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #5844346 - 05/06/13 08:03 PM

I reported wrong data to SkySafari developers with detailed examples.
I'm sorry but they "official" response in Yahoo Groups doesn't convince me. I'm involved in database data as much as they are, you know...
It is my thought they imported their double star data from the CDS of Strasbourg; but the CDS updated their *7-years-old* WDS catalog just in january, after my report emails and insistence. Today, they could easly re-import their data. Or ask me a polished database, along with other catalogs' related info... for free!

Gianluca

Edited by inZet (05/06/13 08:08 PM)


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #5844378 - 05/06/13 08:24 PM

That's fine, Bill, but evaluating observations - from all and sundry - is a significant, indeed essential, part of the Haas Project. And it's done every time someone calculates an orbit for a binary star - if you look at the orbit diagrams in the 6th Orbit Catalog (online via the US Naval Observatory) you'll see that the quality of observations varies quite a lot, especially with older techniques such as filar micrometers. The observations have to be evaluated in order to establish an orbit. Some of them are well off the orbital path.

The point of my reference to observations by myself and others is that these were consistent - in their failure to resolve Gamma Equ - with the data available for that pair. Gamma Equ has been closing gradually since the early 20th century, then likely more quickly in recent times.

My comments on the 1994 measure were to the effect that it was inconsistent with the previous data points and the single later one. Which is what an orbit calculator would also conclude, simply evaluating the evidence. Of course, we now need a new, more recent data point, to establish where things have got to with this pair.

And with regard to any particular observation - one of the requirements of science is "repeatability". So, it's all eyes to Gamma Equ when it comes back into view in a few months time.
I'm planning to ask some of the experienced observers in my local astronomy club to try it, with a variety of medium and larger telescopes. And I'll re-observe it myself, hoping for a night or two of excellent seeing, which can occur here.


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: fred1871]
      #5844462 - 05/06/13 09:15 PM

A further thought on Gamma Equ. I looked at Sissy Haas's book, and she had no personal observation recorded for Gamma Equ. However she did quote TW Webb (from long ago) : "Yellow, white. A striking pair". So I looked up the object in my copy of Webb, because this struck me as being an odd description.

In Webb, the reference is clearly to the very wide pairing of 5 and 6 Equ, which are ~335" apart at present. This is the pairing of stars with quoted magnitudes in Webb of 4.2 and 5.7, and given a number by FGW Struve (STFA 54) which Webb gives. Webb then goes on to mention "K. doubled 4.2, 11..." referring to George Knott's discovery measure of Gamma (=5 Equ).

Reading the note in Haas, which refers to a pairing visible in a finder or binoculars, though this is not mentioned, one might easily expect something different from the real Gamma Equ AB pairing - which has a delta-m of 4.0 magnitudes on current photometry, and greater than 4 mags on old estimates, and is certainly very close.


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Re: Separation Gamma Equ new [Re: fred1871]
      #5844770 - 05/07/13 12:13 AM

Hi Fred. I understand and quite agree with everything you're saying. I am familiar with many of the zealous pitfalls of observational astronomy. (In fact, I remind myself of them every night in the field I have read and understand your comments regarding other's attempts. And that is the essence of why I posted my log. It's there for a challenge to others. By all means go out and refute it! I have about six hours total on the star. Did not split on three previous nights. What I claim to be a successful split was not a quick or casual observation. I studied the object for two hours that evening, with a few pauses for eye relief, etc. I'm not sure what you were eluding to in your second post, but can confirm I was not confusing 5/6 Equ with 5 A-B. 6 Equ remained visible in the 0.21 degree field throughout. As I recall, 6 was lighter, more lemon yellow in color. All I have at this point are my notes and recollections of the evening. I would add for the record; Gamma Equ A is a dazzler. Even in moderately good seeing it tends to jump and dance and mask the companion. I found the split difficult visually due to magnitude difference and glare, not separation. I have split far closer objects with the instrument. Pulling the companion out of the glare and holding it steadily in vision was the challenge on this one. Suffice to say, there is little more any of us can do until Gamma Equ rolls back into the F.O.V. Yes, in the interest of repeatability, I will observe again and hope many others do the same. Let's hope it hasn't moved too much and we find ourselves with another COU 1900 mystery. (Smiles.)

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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #5844907 - 05/07/13 04:51 AM

My current data base of limit observations indicate that a resolution of Gam Equ with an assumed separation of 1" requires a 222mm reflector with 26% CO to have a fair 50% chance and with 190mm you are already outside the standard deviation meaning a much lower chance of about 15% and with 178mm you are then in the very low single digit probability of less than 5% - this means not impossible but in terms of Chris Lord "eXceedingly Difficult".
But my data of limit observations with reflectors is a bit shaky as I myself have so far only used refractors for double star observing - but this will soon change. At least I hope as currently in terms of visual astronomy the foul winter weather is followed by foul spring weather.
Wilfried


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Re: Separation Gamma Equ new [Re: WRAK]
      #5845972 - 05/07/13 03:45 PM

Well I must say this thread has inspired me to give Gamma Equ a try. From what I have been reading here it is going to take a rare night of great seeing for me to even have a slim to none chance, but I'm always up for a challenge. As we roll into summer I will keep this on my to do list.

Thanks to all for your input here!


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Re: Separation Gamma Equ new [Re: WRAK]
      #5846533 - 05/07/13 08:24 PM

Fairly optimistic, Wilfried, but you might be right. I'm still using my older version of the Rule of Thumb, which suggests 320mm for delta-m of 4.0 and 1" separation, and an extreme limit (based on a few observations of mine, of "beyond the limit" pairs being seen, with great difficulty, under exceptional conditions) about 2/3 of that again - so about 210mm. However, that's based on zero CO - refractors. Enhanced energy in the rings from central obstruction will make any significantly uneven pair more difficult. Typical SCT and Mak scopes have OC figures around 0.3 to 0.36. An OC ratio that large provides plenty of transferred energy into the diffraction rings, even with (near-)perfect optics.

And my current analysis of Gamma Equ is that the separation is now most probably less than 1". If that's the case, that makes it harder again.


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Re: Separation Gamma Equ new [Re: fred1871]
      #5891449 - 05/29/13 10:11 PM

Interesting thread.

I just sent my completed results to Sissy last Sunday.

I was able to both resolve and split this double with my 8 inch Orion reflector.

Here are my notes: " 240x [5mm Pentax XW]: resolved; 300x [4mm Radian]: just split; 340x [Pentax 3.5mm XW]: confirmed split"
The seeing on this night was a II (using scale in Chris Lord's paper where he relates his empirical formula for spitting uneven binaries).

I spend a LOT of time looking at uneven double stars and only pen what I am certain of. Frankly, I found 42 ORI from this list to be much more difficult. 46 VIR was no walk in the park either--but it also yielded a split.

I will give this gamma EQU a go again this spring with my 15 inch reflector and report back these additional results.


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Re: Separation Gamma Equ new [Re: Nucleophile]
      #5891467 - 05/29/13 10:25 PM

Thanks so much for reporting in! I concur; 42 Ori was far more challenging.

I neglected to post (in my earlier notes) my first two attempts at Gamma Equ were with a 4" refractor. Only after I e-mailed Sissy with a double negative, did she respond to inform me of this thread discussion and possible changes in the system. Curiosity aroused, went back with 178 mm aperture and first night suspected, second night split. Difference being better seeing and different ocular. The proof for me was defocusing slightly in and out and noting behavior of image. There were two sets of diffraction rings, so I felt satisfied I had seen the companion.

As Fred stated, repeatability is the thing. I for one, will welcome Gamma Equ back for another look. Many thanks, ~ Bill


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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #5893134 - 05/30/13 08:02 PM

Bill, I find your comments, and those of Nucleophile immediately above, of some interest when both of you agree that 42 Orionis was more difficult than Gamma Equ to split.

Looking at the table of data for these two doubles, we find:

42 Ori mags 4.6 7.5 1.1" Dm 2.9
Gamma Equ mags 4.7 8.7 1.0" Dm 4.0

On the numbers one would expect Gamma Equ to be more difficult - primary stars virtually the same brightness, secondary star much less bright with Gamma Equ, and separation of Gamma Equ a tiny bit less.

As I pointed out in another thread on Gamma Equ, it appeared as of 2002 to be continuing to close. In order for Gamma Equ to be easier than 42 Ori, because delta-m is larger (4.0 compared to 2.9), it would have to widen considerably since 2002.

Alternatives - the 2002 measure is wrong. Very unlikely - and Brian Mason at the US Naval Observatory (where the WDS lives) is of the view that the 1994 measure is more likely not correct (2002 is consistent with a closing pair, vide earlier measures including Hipparcos).

Other possibility - photometry is wrong. However we have Tycho magnitudes for these so that's unlikely.

Final possibility - the secondary star of Gamma Equ is variable, previously undetected as such, and observers who happen to look when the secondary is brighter see it, and those who happen to look when the secondary is dimmer, don't.

Following correspondence with Brian Mason I'm hopeful that we'll get a new measure of Gamma Equ in the near future, and that should help "resolve" the discussion. Closer? Wider? The same? We'll see. Meanwhile, I'm intrigued by the 42 Ori/ Gamma Equ comparison, given the descriptions of 42 Ori being "much more difficult" and "far more challenging".


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Re: Separation Gamma Equ new [Re: fred1871]
      #5893493 - 05/31/13 01:01 AM

Hi Fred,

Could it be that 42 ORI is tightening? The most recent WDS entry is from 1995.

What I do know is that I couldn't definitively split 42ORI even after 3 good tries on nights of very good seeing until I resorted to putting a Paracorr lens into the optical train to tighten up the stars.

With gamma equ, I didnt need to stick in the Paracorr, nor try multiple times to observe the split.

-Mark


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fred1871
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Re: Separation Gamma Equ new [Re: Nucleophile]
      #5893536 - 05/31/13 01:44 AM

I should've checked the date of the last measure for 42 Ori - you've reminded me that I wondered about that back when I observed it a while ago.

Yes, it has been tightening slowly over time since discovery in 1848, though given its past history since discovery by WR Dawes, the tightening has been nearly linear (little change of angle) and pretty gradual. I don't have the full list of measures to hand, but those I do have suggest a big change since 1995 is unlikely.

Probably the separation, assuming roughly a continuation of what happened from 1848 to 1995, in the 18 years since 1995 has come down to 1.0".

If we take the 1848 measure (2.0") and 1995 (1.1") the average time for a reduction of 0.1" in separation is 16.3 years. If we take the period 1926 (1.6") to 1995 (1.1") then the average time for a reduction is 13.8 years. Slightly quicker. However even in my current data I can see some scatter in the measures, so the difference might not be of much significance.

So, if we assume 42 Ori is now at 1.0" (or 0.95" - and the 2002 measure of Gamma Equ was 0.96") we still have the problem that the Delta-m of Gamma Equ is 4.0 mags to 42 Ori at 2.9; and your experience, and Bill's, that Gamma Equ was a lot easier than 42 Ori.

I've observed 42 Ori and can only agree it's a very difficult double with moderate telescopes, even in very good seeing conditions.


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Re: Separation Gamma Equ new [Re: fred1871]
      #5893552 - 05/31/13 02:07 AM

It seems we need some more observers to look at these and report their results during the next cycle. It is curious--but that's what makes it fun.

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Re: Separation Gamma Equ new [Re: Nucleophile]
      #5893619 - 05/31/13 03:28 AM

Interesting comments on 42 Ori - I had this year this few successful observations (due to an unbelievable lack of clear skies) that this one stucks in my mind: At ~210° pointed elongation of 42 Ori indicating the position of the companion like a hour hand on a watch. This may be one of the rare examples where a fainter companion is an advantage as with equal bright stars the position of the companion would have been not this clear, at least not with 140mm.
To give Gam Equ another try I have to wait for mid September but here I see not the slightest chance with 140mm and hope that I have come on peaceful terms with my C925 then.
Wilfried


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Re: Separation Gamma Equ new [Re: WRAK]
      #6037894 - 08/21/13 08:50 AM

Has anyone had a chance to revisit this one already? I had very good seeing last night but with the Moon out in full swing and at low declination, I could not quite make this one out.

Roberto


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Re: Separation Gamma Equ new [Re: R Botero]
      #6038222 - 08/21/13 12:03 PM

Not yet - but in a few weeks it will be in my field of view.
Wilfried


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Re: Separation Gamma Equ new [Re: WRAK]
      #6062285 - 09/04/13 08:32 AM

Given the seeing I had last night and no moon I thought I would give this one another go. I have to admit I did not see it. There was perhaps a hint of bump in the primary's first diffraction ring (at 450x with my 6" f/7.5 refractor) - a bump that I could not attribute to seeing as the rest of the diffraction ring did not exhibit this at all - but it was not a clear split. It appears the good seeing will continue tonight so I will have another go...

Roberto


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: R Botero]
      #6095961 - 09/22/13 11:01 PM

Gamma Equ definitely "prime time" now. Have been awaiting... clouds, moon, you all know the drill. Hopefully next weekend...

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azure1961p
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6095993 - 09/22/13 11:17 PM

Roberto keep us posted. Unless I luck out with cool weather good seeing Im done with challenging doubles till perhaps June next summer. I can still luck out even through November but it gets progressively more difficult.

Bill, like Roberto's efforts I look forward to yours as well.


Pete


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6104117 - 09/27/13 12:44 PM Attachment (63 downloads)

Friends, I was able to observe Gamma Equ last night for an hour and twenty minutes. The companion was resolved at x300, with x400 providing the best view. The image was consistent with what I observed last Fall, except I was observing it at higher altitude, as it crossed the meridian. Fred, the wide double you mentioned was just outside my 0.15 degree field. I did not see much yellow to it last night, probably due to the higher altitude. I have a crude illustration that should give an idea of what I'm seeing...

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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6104121 - 09/27/13 12:45 PM

Click attachment in above post to view. Thanks! ~Bill

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R Botero
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6104295 - 09/27/13 01:52 PM

Great news Bill! Illustration is very nice also. I've had nothing but clouds for weeks now.

Roberto


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Re: Separation Gamma Equ new [Re: R Botero]
      #6104433 - 09/27/13 03:18 PM

"Remarkably, the companion is dimmer than the diffraction ring artifacts, but consistently displaces the arc and can be held steadily in vision"

Remarkable indeed - delta-m between the central disk and the first ring should be with CO 0.28 about 3.5 while delta-m for Gam Equ is 4 so this conforms to the observation. To see a secondary sitting on the first ring being at the same time fainter than the first ring borders on magic. But if correct this position would indicate a separation of about 1.13" assuming again CO 0.28.
I fear I will not be able to verify this observation with my 140mm refractor although the secondary should sit near the first minimum of the diffraction pattern means Rayleigh but I expect this delta_m is a bit too large for such a small aperture. My current RoT calculator suggests 190mm aperture with 1.13" separation for Gam Equ - I will certainly try with 140mm but expect nothing (and will quit within a few minutes if not seconds if I see no chance for a resolution - I admire observers who are patient enough to observe a binary for half an hour or longer).
The delivery for the 200mm Dall-Kirkham with CO 0.25 (this scope should do it I hope) I ordered in spring has slipped to begin 2014 so I will have to wait for another year. But with this scope I will also be able to reduce aperture with masks down to 150mm with CO still less than 0.35 to get a confident estimation for the limit aperture for resolving Gam Equ.
Remains interesting.
Wilfried


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fred1871
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Re: Separation Gamma Equ new [Re: WRAK]
      #6105004 - 09/27/13 09:55 PM

I'll agree with Wilfried's comments here. In particular, being able to see the secondary on the diffraction ring is remarkable given the relative brightness of ring and star. I'm planning another attempt on Gamma Equ, using a C9.25, the benefit being that the secondary star won't be on the first diffraction ring if it's now moved to ~1.13" as Wilfried calculates from Bill's observation. It should at that separation be outside the first diffraction ring for 235mm and CO ~0.37, so easier to see.

Some comments on the orbit might be informative here. First, of course, it will be good to see a new measure of Gamma Equ to discover what it's currently doing. That's the missing element at the moment; we don't have a recent-enough measure. Evaluating observations is therefore difficult, involving estimates, and orbit projections, etc.

The pair was consistently closing in the late 20th century, despite the outlier measure of 1994; the 2002 measure of 0.96" should be accurate to a high level; so ~1.13 would suggest the pair is widening again. That amount of widening appears possible in the 11 years since 2002, based on the difference between the Hipparcos/Tycho measures of 1991 and the 2002 figure.

The orbit of this pair appears to be seen nearly edge-on from Earth, given the small change in PA over 135 years of measures. Of course, it might be an artefact of the section of orbit so far seen - nearly linear, but starting to curve in recent times (implying it's less edge-on). The PA did appear to be drifting a little in the more recent period; after being around 275 for many decades, it had moved only to ~268 in 1958, but to ~264 in 1991 and 258 in 2002.

The increased rate of change in the more recent measures, in separation as well as angle, suggests the periastron section of the orbit. If so, it's a matter of how close the pair gets over what time period. An increase in separation to the present date, compared to 2002, is a surprise, suggesting a rather quick periastron period, perhaps with 2002 being near minimum separation. So it might be possible, if somewhat unexpected; again, a new measure would answer that question. The orbit is quite large - the distance, about 118 ly, combined with the movement history, suggests an orbital period of perhaps a few hundred years given the scale involved. Rapid change will be around periastron.

So, a useful observation, Bill. We'll see how repeatable it is by other observers, with other telescopes. It might turn out that you've got a "best possible" result for the aperture used. That's one of the problems of the unequal pairs project; we can expect a bell-shaped curve, where "best" can't be achieved, even 50% of the time in good conditions, by everyone - observer visual acuity for doubles varies a lot, same telescope, same night, etc.

Okay - it's time for the rest of us to attempt Gamma Equ again.

Edited by fred1871 (09/28/13 03:38 AM)


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: fred1871]
      #6105252 - 09/28/13 02:31 AM

The world is waiting...

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WRAK
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Re: Separation Gamma Equ new [Re: fred1871]
      #6106308 - 09/28/13 04:54 PM

Quote:

.. I'm planning another attempt on Gamma Equ, using a C9.25 ...outside the first diffraction ring for 235mm and CO ~0.37...




Fred, I assume CO for your C925 is 0.383 as the mounting of the secondary mirror makes up for a CO of 90mm and this is probably already too high to be of good use for resolving highly unequal binaries like Gam Equ even if the compnaion is sitting in the second minimum. Looking forward to your report.
Wilfried
PS: May be you can ask Bill for a spell on your scope


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: WRAK]
      #6108500 - 09/30/13 12:27 AM

Wilfried,

Since you are the one who started this thread, I am elated to learn you will be able to give a "few seconds" of observing time to the subject, (once you have acquired the proper instrument), in ... 2015?

A true testimonial to your sincere interest in the topic.

Ever Onward...


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fred1871
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Re: Separation Gamma Equ new [Re: WRAK]
      #6108615 - 09/30/13 02:42 AM

Wilfried, I'd intended observing Gamma Equ last night with the C9.25, but unfortunately my go-to mounting would not go where it was told, apparently due to a balance problem; and as the SCT needed collimation tweaking, I decided not to waste a steady night - so I set up the 140mm refractor (go-to worked very nicely with that).

And so to Gamma Equ - but, to give the conclusion first, without success. I made Gamma Equ my first double of the night, and at 285x and 400x there was no companion. Seeing was good, a little flickery, and motion in the first diffraction ring. I observed for a few minutes, changing eyepieces back and forth, so re-focusing as well.

I then went on to other doubles, and because of the good seeing, which improved over time, I looked at various difficult pairs that were on my list, equal and unequal.

I went back to Gamma Equ later in the night, when it was still at good altitude, and the seeing had improved further. On the second attempt I tried powers of 333x and 400x initially, both with Ortho eyepieces that give very little light scatter. No companion. 570x showed the same result, no companion. THe first diffraction ring still had some movement over time, and every now and then gave the impression of a star point as an isolated spot where the ring was, but watching over a few minutes at various powers it was clear that it was a seeing artefact.

So I'll go with the possibilities that at present, either (a) Gamma Equ is at ~1.13" but that's still too difficult for a 140mm refractor, even though it has widened since 2002, or (b) that Gamma Equ is closer than the 1.13" estimated by Wilfried - my observation doesn't tell us that, but is consistent with it.

The various other doubles I looked at between Gamma Equ observations, and following the second observation, showed pretty well. I got elongation on various very close near-equal doubles - 72 Pegasi at 0.6" (ephemeris 0.57"); STF 2597 despite Delta-m 1.1 at 0.6" (ephemeris suggests 0.65"); the short-period binary HO 296 in Pegasus, again delta-m of 1.1, at 0.5" in 2012 and with an ephemeris separation of 0.485" for 2013.75.

A more uneven tough pair was BU 249 in Aquila - mags 7.4 and 9.4, measured at 0.8" in 2008; 333x showed the close companion as an extension of the primary, confirmed at 400x. BU 693 in Aquarius also showed double - mags 7.6 and 9.9 at 1.0" - a 1991 measure, but it had shown no sign of changing separation over time.

The recently discussed DJU 4 (13 Vul) yielded as a neat uneven close pair at 333x, despite being on the first diffraction ring with 140mm. Mags 4.6 and 7.4 at 1.4".

So it was a good observing night, regardless of not seeing Gamma Equ as two stars. Various other pairs rounded out the night.


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Re: Separation Gamma Equ new [Re: fred1871]
      #6108653 - 09/30/13 03:42 AM

Fred, congratulations - great observations with 140mm. In terms of RoT proposed aperture BU249 should be equal difficult with Gam Equ.

Bill, with locating and changing eyepieces up to the required magnification I certainly need more than a few seconds for a specific object. If the resolution is not instantly given I will then give it several tries with moving through the field of view and tweaking focus combined with hope for moments of better seeing - what seems then seconds for me due to high concentration will take may be at least 5-10 minutes (I am always surprised how fast time runs when I am doing a session) - but then I will move on regardless if successful or not as I can simply not maintain this high concentration much longer without spoiling the rest of my planned session. And I really admire observers who are able to keep their concentration on one object for much longer time. But you need not worry that I will not give Gam Equ the necessary time with my 140mm refractor and if I ever get the 200mm DK with 0.25 CO I expect Gam Equ anyway to show the companion without troubles. If not then further investigations are required.
Wilfried


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Re: Separation Gamma Equ new [Re: fred1871]
      #6108661 - 09/30/13 03:58 AM

Fred, am I to understand that (after your last diatribe) were unable to FIND Gamma Equ because of a "faulty go-to system" ?????? !!!!!! Get your head out of your... um.... Objective Lens.

I'm glad to hear the seeing was good. I leave you and your friend to your mutual admiration society. You guys are a riot!


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fred1871
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6108680 - 09/30/13 04:50 AM

You're misreading what I said and what can reasonably be implied. The go-to system was giving wrong positions for stars straight out of set-up. Putting in RA and Dec consequently would take it to a wrong (wildly wrong) position. So there was no point going on with the system in that unhelpful condition. By changing over I had a useful and useable system that allowed use of a good observing night.

What's needed now is for a lot of other observers to look at Gamma Equ and report on seeing it double, or not, and describe their circumstances (telescope, seeing, magnification, what they saw). Obviously, with a large delta-m and small separation, good air steadiness is one of the essentials.


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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6108715 - 09/30/13 06:29 AM

Quote:

... I leave you and your friend to your mutual admiration society. You guys are a riot!




Come on Bill, relax a bit. You did a great job observing Gam Equ and I take your report as serious positive even if I made more or less funny remarks concerning magic (I still can not understand how it is possible to resolve a companion sitting in the first ring being fainter than the ring but I will investigate this topic anyway) and duration of observation.
I apologize if this offended you, was not my intention.
Wilfried


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Re: Separation Gamma Equ new [Re: WRAK]
      #6109154 - 09/30/13 12:02 PM Attachment (28 downloads)

I have been following this thread with interest these past months, with the 415mm (16.3"),f/16, Dall-Kirkham Cass: 19% CO and decided to give the star some scrutiny in recent weeks.

What came out of it I find quite perplexing: several times it was “Yes!!!” then back came the uncertainties. There was usually more certainty with the apodizer applied; and one near-certainty with the 6” off-axis mask; but this ‘companion’ seemed relatively too bright. The attachment summarises most of my impressions.

In addition to what is shown there I can detail a Gamma Equ observation/session on Sept. 28 in very good and improving conditions. Keeping on it for over an hour (in spells!); initially sweeping it up in twilight. At first the impressions were as in the attachment. However as the seeing got better doubts with the companion increased. In the end I applied x665 (non-binoviewer) and still had a very good Airy with well defined rings. But no sign at all of star B! I was starting to wonder if I had strayed onto 6 Equ but no – anyhow its marked blueness would have been the giveaway.

One old trick, which I have tried before successfully (10” Newt.), is to slightly tilt the primary mirror to throw the rings away from where a faint companion might be. Not wanting to disturb the D-K’s collimation I removed the barrel from the 10mm Ortho (Zeiss) I was using; and with a bit of Blue Tack achieved the right tilt to get the same result – and absolutely no companion evident! I’ve not tried this eyepiece-method before so it awaits more clear nights to check it out.

I have seen some mention of the comes being variable and I note that Burnham’s Handbook gives it as a fainter magnitude of 11 as opposed to 8.7, which might indicate an M dwarf but if it is a flare star it must be one of very unlikely vigour!! I have spent hours on occasion with YZ CMi and got a measly, uncertain, 0.3 mag. ‘flare’! Kaler suggests G9 – K0 for Gamma Equ B. which seems to accord with my impressions of light orange at times.

Later in the night I applied the same technique to 85 Peg (0.52” 317º) and got a more definite glimpse (some uncertainty) of the companion than with all my efforts on Gamma Equ. But, as I say, more checking in prospect.

Regards,
David.

Edited by David Gray (09/30/13 03:50 PM)


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Asbytec
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Re: Separation Gamma Equ new [Re: David Gray]
      #6109259 - 09/30/13 01:09 PM

Excellent report, David. I'm itching to try this one. Your description of "over performing" success brings it home for me - fluctuating between "yes" and uncertainty. You're one time near certainty with a 6" mask is enough to motivate me to take on the challenge. Plus, the observation is one of those that fall into the realm of interesting.

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Astrodj
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Re: Separation Gamma Equ new [Re: David Gray]
      #6109304 - 09/30/13 01:40 PM

I too have kept following this thread with interest. Last night was my first attempt at observing Gamma Equ.

My results were negative on AB, some details follow.

ZLM= 5.5
Transparency= 9 of 10
Seeing= 5, occasionally 6 of 10
10" f/4.7 Nwt, CO 25%
Equatorial platform
Magnifications= 182x, 300x, 364x, 600x
Eyepieces used= 6.6mm Cave Orthostar, 4mm Nihon Seiko Ortho, 2x 3 element Barlow

The 12.5 mag AC companion was easily seen. WDS shows a P.A. of 359. I estimated the P.A. of AC at 005 while at the scope and looked it up later. I used that as a reference for where to concentrate my search for AB. Diffraction rings were breaking up into points that shifted in and out from the primary. In occasional moments of better seeing the rings steadied enough to look like two diffraction rings, albeit briefly.

I had several impressions of a star point near the first diffraction ring that must ultimately be attributed to seeing artifacts as they were at a P.A. of between 25 and 45 degrees. Nothing was seen at the correct position angle that would suggest a 9th mag star.

I will try again, of course...


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Cotts
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Re: Separation Gamma Equ new [Re: Astrodj]
      #6109363 - 09/30/13 02:28 PM

Can't find it for two nights at Okie tex. 16" Zambuto f/5, 19% central obstruction.

Will keep trying.

Advice from a mod:
If you haven't seen it and you haven't tried, don't post.
If you haven't seen it but have tried, don't tell someone else they couldn't have seen it ( by hinting or direct comment)
If you have seen it, post your results dispassionately.

Dave


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David Gray
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Re: Separation Gamma Equ new [Re: Asbytec]
      #6109485 - 09/30/13 03:39 PM

Thanks Norme,

Actually I thought this one was going to be a walk in the park! If I did get the companion then I suspect it nearer mag. 10 than 9.

I was a little hasty with the graphic which I had started, and left, some weeks back and have amended a couple of things for correctness.

Cheers,
David.


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fred1871
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Re: Separation Gamma Equ new [Re: David Gray]
      #6109970 - 09/30/13 08:33 PM

David, a very useful report on your observing efforts on this difficult object. It's certainly more of a problem than most of us expected it to be!

Considering magnitudes again, if the secondary star is dimmer than mag 8.7 then the pair becomes more difficult; and the 19th - to early 20th century observers did usually assign a magnitude around 10 or 11 to it. Brighter than that starts with van den Bos in 1958, using the Yerkes 40-inch refractor. The pair was easier at that time than later, it had begun closing but was still reasonably wide - he got a measure of 1.94". Worley in 1988 (26-inch refractor) suggested a delta-m of only 3.3 (mags) - surprisingly bright. Hipparcos and Tycho put the delta-m at 4.25 and 4.0 respectively (1991 for both). Roberts in 2002 has delta-m 3.82, but that's in an R band (red light). If as Kaler suggests the companion is type G9-K0, the companion can be expected to be brighter in R than in V, and thereby reduce the delta-m as the primary is less red (type A9V).

Burnham's Handbook appears to have used the 19th century estimates of brightness for the secondary.

So it's still an open question of whether the secondary is variable; but if it were usually fainter than mag 8.7, we'd have an even more difficult double, so that doesn't help for telescopes of moderate size.

Your "messing around with ellipses" diagram is interesting - I'd suggest the larger ellipse, while possible, is unlikely; and Kaler's suggestion of ~250 year period would be similar to the smaller ellipse. You've plotted the 1994 measure, which shows how far out of trend it is (the briefly-reversing binary ). The curve does suggest a pair continuing to close. Now if only we had a 2013 measure to confirm, or dis-confirm, that.

Your note about "eye estimates for the position" of the secondary also is a fit for an orbit continuing to close, and for a more rapid change and decrease in the PA; consistent with the diagram. So those observers with suitable telescopes should be checking for the possibility of a companion with noticeably smaller PA than previously, 220-250 as per your eye estimates; as well as very close, in the 0.6"-0.8" range. As the first diffraction ring with your 16.3-inch will be near 0.5", that's consistent with your drawing A.

So it's possible, but not certain, as you acknowledge, that you might have seen the secondary star.

Your observation in good conditions of 85 Pegasi is a useful check on what's possible. The delta-m for that pair is similar to Gamma Equ - 85 Peg has WDS mags of 5.83 and 8.9, so delta-m ~3.1, and the very good orbit for 85 Peg means there's no significant uncertainty in the separation you quote (0.52").

My final thought is that I envy you with a 16.3-inch DK with small secondary; seems to me it's a pretty much ideal planetary/double star telescope.


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azure1961p
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Re: Separation Gamma Equ new [Re: Cotts]
      #6110074 - 09/30/13 09:27 PM

Quote:


If you haven't seen it but have tried, don't tell someone else they couldn't have seen it ( by hinting or direct comment)

Dave




Well said.

Fred you might be interested to see the .17" double split Dave illustrated in another forum.

Pete

Edited by azure1961p (09/30/13 09:47 PM)


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fred1871
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6110236 - 09/30/13 10:44 PM

Pete, yes, I did see that, showing a 0.17" pair as elongated, in the thread about "Detail on Ceres?" - an excellent result, and entirely believable given the telescope etc; consistent with Christopher Taylor's efforts, with RG Aitken's comments, etc. But I won't personally be attempting A 2145 with the (much) lesser telescopes I currently have.

Regarding telling other people - there's an implication involved, even if you're merely discussing the limits of physical optics, that someone could not have seen what they claim. An error has crept in. No dishonesty involved; incompetence isn't needed, we all sometimes get false positives. So if someone claims to see a double as a double at 0.5" with, say, a 63mm Zeiss Telementor (a very fine little telescope), the only response, whether or not you say it, is that it's beyond the bounds of possibility for that aperture.

That's because it goes beyond the physics, and no matter how keen the eye, it can't see what the optics can't show. As I've said before, that's quite different from differences in colour perception; and quite different from seeing fainter, where visual acuity can make a big difference.

In the case of Gamma Equ, we can say that the 1994 measure is anomalous, an "outlier" in Brian Mason's diplomatic language, plainly some kind of error is there; and David Gray's plotting of the measures shows that well enough. Is it a typo? - a copying mistake? - an error with the measuring system? - we can't tell, and the astronomer who made the 1994 measure is very competent and very experienced. But everyone has the occasional error, and later they might be able to identify how it happened.

Meanwhile, looking at what David Gray can see with his 'scope, I've got the same feeling Jonckheere had when using his first serious telescope for double stars - it was near 9-inch aperture, and he did not think it big enough - so his next telescope was a 14-inch, much more satisfactory. Sometimes the only way forward is more aperture, given optics of suitable quality and design.

Edited by fred1871 (10/01/13 08:25 PM)


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azure1961p
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Re: Separation Gamma Equ new [Re: fred1871]
      #6110276 - 09/30/13 11:07 PM

There's interesting things in the errors that come through poor measures. Its a little frustrating on one hand but it adds a wild card element that can leave a lot in the lap of the observer. At anyrate I for one had no idea this double was this terribly difficult. Discovery is still alive here and that's a good thing.

Pete


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WRAK
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Re: Separation Gamma Equ new [Re: David Gray]
      #6110553 - 10/01/13 03:44 AM

Quote:

... one near-certainty with the 6” off-axis mask; but this ‘companion’ seemed relatively too bright...




David, do I understand it right that your other observations made this a false positive?

Regarding your observations with full aperture - impressive report. With an aperture of 415mm only seeing should be the limiting factor for resolving Gam Equ if the advertised data would be at least nearly correct - so may be seeing is the reason for the remaining uncertainities. It also shows that even evidently positive observations have to be double checked. From the specs of your DK scope would result a separation of about 0.6" - even with this small separation Gam Equ should be rather easy resolved with 415mm if +4.7/8.7mag are correct. I think you would come to the limit of your scope with 0.6" +4.7/~10mag.
But all this means that I will not only have to forget about my 140mm refractor but also my coming 200mm DK not to speak about the C925 with it's counter productive CO of nearly 0.4 - or I might have to put a mighty spell on it.

Remains quite interesting.
Wilfried


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Asbytec
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Re: Separation Gamma Equ new [Re: WRAK]
      #6110731 - 10/01/13 08:30 AM

Quote:

...do I understand it right that your other observations made this a false positive?



Or a positive maybe.


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David Gray
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Re: Separation Gamma Equ new [Re: WRAK]
      #6111338 - 10/01/13 02:19 PM

Quote:

Quote:

... one near-certainty with the 6” off-axis mask; but this ‘companion’ seemed relatively too bright...




David, do I understand it right that your other observations made this a false positive?




As it stands I guess I would say that. But as far as the 6" off-ax. goes it is based on very few tries. I am modifying the mask for quicker attaching/removing as it is too tight a fit; supposed to 'drop' in the end and also needs a central knob or such.

I am only hoping my recent good seeing has not ended. They have just harvested and ploughed the adjacent wheat-field and I have suspected, over the years, that this seems to affect my local seeing for some weeks. Perhaps coincidence or simple supposition I don't know.

I will persevere regardless with Gamma Equ. I am hoping to check out similar doubles to further evaluate things. I will be trawling Sky Map of course but suggestions welcome - preferably those following the meridian as I have houses to the s'west and seeing is less reliable that direction.

This is an intriguing challenge and thank you all for your comments and insights on my report. Hopefully further offerings - inc. other doubles in due course!

Cheers,
David.


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WRAK
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Re: Separation Gamma Equ new [Re: David Gray]
      #6111556 - 10/01/13 04:46 PM

Some suggestions:
ID Name RA Dec Separation Magnitude Magnitude2 Constellation
WDS02132+4030 MET14 02:13:13 +40:30:28 0,7 5,68 9,88 And
WDS04564-0510 HDS641 04:56:24 -05:10:17 0,6 5,49 9,64 Eri
WDS05397+2554 OCC231 05:39:44 +25:53:50 0,6 5,18 9,46 Tau
WDS06042-0643 HDS826 06:04:13 -06:42:32 0,6 5,24 9,45 Mon
WDS07123-4030 HDS1001 07:12:16 -40:29:56 0,7 5,31 9,4 Pup
WDS07187-2457 TOK42 07:18:42 -24:57:16 0,9 5,33 9,7 CMa
WDS08116+3227 CRJ2 08:11:39 +32:27:26 0,6 5,09 10 Cnc
WDS08319+5037 CRJ3 08:31:55 +50:37:00 0,9 5,96 10,07 Lyn
WDS08345-0044 MET53 08:34:32 -00:43:34 1 5,44 10,28 Hya
WDS13239+5456 PSF1 13:25:14 +54:59:17 1 4,01 8 UMa
WDS16278-0822 RST3949 16:27:48 -08:22:18 0,8 4,71 8,83 Oph
WDS17177+3717 HDS2446 17:17:40 +37:17:29 0,9 4,62 8,53 Her
WDS20176-1230 WZ15 20:17:39 -12:30:30 0,8 4,44 8,6 Cap
WDS23300+5833 STT496 23:30:02 +58:32:56 0,8 4,87 9,3 Cas
WDS23587-0333 BU730 23:58:40 -03:33:21 0,8 4,9 8,9 Psc
Wilfried


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David Gray
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Re: Separation Gamma Equ new [Re: WRAK]
      #6112515 - 10/02/13 06:22 AM

Many thanks for these Wilfried – might get to look at some of them in a couple of days if the clear-sky forecasts hold……!

With regard to gamma Equ I have to say if I had included this in my occasional, more casual, double star forays then on the basis of my more-convinced ‘sightings’ I would have probably moved on to the next object quite satisfied as to the companion detected ! The need for more experience my tackling this type of double seems indicated…..

You may right with Bill's observation and I hope he continues to tackle gamma - I've not laid the matter to rest that's pretty sure!

David.

Edited by David Gray (10/02/13 08:50 AM)


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WRAK
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Re: Separation Gamma Equ new [Re: David Gray]
      #6112542 - 10/02/13 07:08 AM

David, regarding aperture mask - with a CO this small you could also use regular aperture masks down to 10" aperture without getting CO larger 0.28 and still expect performance of an 8" refractor. Should be enough to resolve Gam Equ if the WDS data is near reality but with less influence of seeing.

Meanwhile I wonder if Bill has seen a ghost (some kind of reflection of the primary within his optics) as the observation report includes two irregular aspects: Fainter companion seen in interruption of brighter diffraction ring and defocus producing ring around the secondary and not the primary as to be expected.
Wilfried


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David Gray
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Re: Separation Gamma Equ new [Re: WRAK]
      #6112628 - 10/02/13 08:45 AM

Wilfried, I had something in mind a while back for on-axis masks - could even simulate certain sized SCTs (CO-wise) this way. But your 10"-cum-8" 'refractor idea has not occurred to me but will certainly give it a go.

I did allude to this somewhere on CN; possibly on Norme's Multi-mask thread: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6017180/page...
There is a fair bit of detail re. my efforts with masks/apodizers and touching on doubles.

Bills observation: could be some seeing effect - I have been getting some apparently anomalous too-bright 'companions' throughout my investigations. I've not proved much - hope he continues to tackle the star.

David.

Edited by David Gray (10/02/13 09:01 AM)


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WRAK
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Re: Separation Gamma Equ new [Re: David Gray]
      #6114531 - 10/03/13 03:15 AM

Tried it last night with 140mm and seeing Pickering ~6 but it was hopeless as the diffraction pattern was not stable enough to be able to identify any faint spot between disk and first ring with such a small aperture. Think Gam Equ meanwhile rather impossible with 140mm, only perfect seeing could may be do the trick.
Did not see much sense to try it also with the C925 with the given seeing.
Wilfried


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: WRAK]
      #6116553 - 10/04/13 04:03 AM

The primary is estimated magnitude 4.7. The secondary is magnitude (estimated) 8.7. It IS dimmer... (forgive the vernacular).

1. I am certain I don't have enough experience.
2. I am certain my observations are spurious.
3. I am certain my mirror is "pinched."
4. I am certain I made an arithmetic error typing in the P.A. at 4 am in the morning, last year.
5. The lords of the double star section have asked for repeatability and I have given it to them. I remain in waiting...
6. I am relaxed; I just resolved Kui 97 (Cygnus). It was beautiful! (Same spurious observation, same inexperienced observer, same pinched mirror... it was beautiful!)

You guys have fun doing what ever you're doing....

I leave you to your work.


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WRAK
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117107 - 10/04/13 11:53 AM

Quote:

... I just resolved Kui 97 ...



Congratulation, certainly a challenge for 178mm, excellent acuity of vision.
Should be a tad easier than Gam Equ with given WDS data and a lot easier if the companion of Gam Equ IS dimmer than advertised as you say.
Wilfried


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Cotts
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Re: Separation Gamma Equ new [Re: WRAK]
      #6117402 - 10/04/13 02:41 PM

At Okie Tex we have had astonishingly good viewing weather. Six nights in a row of crystal clear skies, lows in the 50's and high 40's. Seeing from below average to above average. I tried Gamma Equ every night at least twice, early and late, with my 16" Zambuto f/5 dob with powers up to 800x.

At no time was I given any hint of a companion. There were times that the seeing was good enough to briefly show the inner diffraction pattern of the star, indicating seeing approaching 0.25". No companion.

If, as bill says, the delta magnitude is 4 and the separation is 1.1" or less, then we have an excruciatingly difficult pair here.

Dave


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: Cotts]
      #6117545 - 10/04/13 04:07 PM

Just to clarify, I'm not claiming the secondary is dimmer than advertised. I'm claiming it is dimmer than the primary... (I see the prime as white-cream white, secondary as a tiny sparkle, white-blueish, the darker shade being on the side away from the primary). Because of the difference in hue, the illusion of magnitude difference is amplified. The diffraction ring arcs on my illustration were as bright or brighter (seemingly) than the companion. But the secondary sat there plain and still - never wavered.

I am interested and somewhat astonished to read Dave's entry above. Wow! I trust those results with that kind of aperture and seeing. And I know his logs. I certainly don't have any idea why this object is so tough. I have a request in to one of the Haas contributors in FL, using a 14.5" dob if he will give it a shot.

It occurs to me, that I have more than once seen a double star better using less aperture, not more. Seems counterintuitive, but the more light gathering ability, the more glare in some cases. 90 Her is another on the Haas list that is far more challenging than the data suggest.

I don't know what else to say about it. My first two attempts last year were throw away, because I was using 100 mm. I got my first resolution on my second attempt with 178 mm. This year, I found it surprisingly easy - as soon as I hit x300; there it was. I viewed it on and off for an hour and twenty. The star never left the field and the secondary never wavered. Time permitting, I will make another observation, record everything as carefully as I can and attempt a color illustration for reference. Good luck to all. It is tough. Has Mark (Nucleophile) weighed in on this one yet this season? He got it last year, too. I'm also interested to see if Roberto can grab it with 152 mm and good sky.


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Bill Boublitz
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Re: Separation Gamma Equ *DELETED* new [Re: Cotts]
      #6117553 - 10/04/13 04:07 PM

Post deleted by Bill Boublitz

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Bill Boublitz
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117569 - 10/04/13 04:21 PM

Here's an idea; Has anyone thought of an occulting bar? I don't have one, but I bet that would do it!

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Bill Boublitz
super member


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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117575 - 10/04/13 04:24 PM

I deleted the above post because it was accidentally a duplicate of my first entry above...

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Cotts
Just Wondering
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117606 - 10/04/13 04:44 PM

Bill, you need to delete 7 more 'copies' of your post...

As for the topic at hand, aperture may indeed be my foe. We'll soon see as I will be trying this pair from the Chiefland Fall Star Party in much better Florida seeing conditions.

Dave


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: Cotts]
      #6117845 - 10/04/13 07:16 PM

Damn... What happened? Sorry gang. It wasn't me, I swear.

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Cotts
Just Wondering
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117896 - 10/04/13 07:58 PM

An old idea for viewing the moons of Mars: Take a dark blue, violet or green filter, 1.25". Remove the glass from the cell, cut the filter in half with a glass cutter, replace the half filter in the cell and place in the eyepiece focal plane.

Many modern eyepieces have the focal plane between the lenses so older designs like orthos, plossls, RKE's, Kellners etc. are the eyepieces of choice...

the trick is to get the edge of the glass exactly at the focal plane of the eyepiece.......

the advantage of this is that you can still see the primary but it is greatly reduced. Just rotate the eyepiece to the correct PA and the secondary may be more easily visible.....

I'm going to try to make one of these out of an old 6mm ortho that I have in my junk box.....

Dave


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fred1871
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6117961 - 10/04/13 08:40 PM

Bill, your success with Kui 97 in Cygnus is of interest. What magnification, what seeing conditions, and how easy/difficult was it?

Reason for asking is that I'm seeing odd variations in what can be achieved in unequal doubles observing. There are some examples of pairs that, on the numbers, should be more difficult than others, but prove less difficult. I've had the same experience myself - one night I had two doubles near each other, on the numbers X is tougher than Y (slightly); but X was easier/more obvious than Y. Yet the photometry in WDS seemed fine, and the measures history of both seemed fine. I remain puzzled - same observer, same telescope, one observed straight after the other (then a back and forth check).

Kui 97, on the numbers, is tougher than 42 Orionis. But from your comment ("it was beautiful") it sounds as if you found it easier. Both doubles, Kui 97 and 42 Ori, have delta-m of 2.9; but Kui 97 is closer, 0.8" compared to (probably) 1.0" for 42 Ori (1.1" listed a while ago, but slowly closing).

Now it might be that Kui 97 is easier because it sits in the first dark interspace of the diffraction pattern - which is ~0.8" for 7-inch aperture. Where 42 Ori for that aperture is roughly on the first bright diffraction ring.

In the case of 90 Her, the first diffraction ring should sit on the secondary at ~125mm aperture. So, noting the list of successes on that one, on the Haas project website, I see 3 positive reports for 100mm, only 1 each for 120mm and 130mm, and 4 for 150mm. Which suggests the possibility that the diffraction ring has an effect here; more reports would confirm or dis-confirm this. Of course, it might just mean fewer observers have 120-130mm telescopes.

So, some variations can be regarded as consistent with the effect of diffraction rings on faint companion visibility. But others don't seem to fit that model. I've used 90 Her and 42 Ori as cases where diffraction does seem to have explanatory value.

In the case of Gamma Equulei we have a problem insofar as attempting to evaluate observations doesn't have a current measure to work from. We don't definitely know whether the pair is similar to 2002, closer, or has started widening again. David Gray's experiments in orbit tracing suggest but can't prove that the pair is likely closer than 2002. So all we can do for now is gather observing reports, and eventually, when we have a new measure, evaluate from there.

Meanwhile, Cotts' attempts and David Gray's are suggestive of a VERY difficult double.


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WRAK
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Re: Separation Gamma Equ new [Re: fred1871]
      #6118497 - 10/05/13 04:26 AM

HDS2446 in Her 0.9" +4.62/8.53mag seems to be a good candidate for checking resolution of a double with comparable advertised data to Gam Equ. If the data for Gam Equ is correct it should be doable with 200mm with reasonable seeing and with 180mm with very good seeing - although with a delta-m of 4 any CO size might already be counter productive. Large aperture being a foe for resolution? Don't know - only with inadequate seeing - the most difficult doubles were always discovered with very large apertures.
Wilfried


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Asbytec
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Re: Separation Gamma Equ new [Re: WRAK]
      #6118725 - 10/05/13 10:02 AM

I gave Gamma Equ a good hour tonight. No go at any mag from 310 to 390x. NELM about 4.5, seeing 7/10. Field stars down to 12th mag were visible, but the 9th mag companion was not. Not even a hint.

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azure1961p
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Re: Separation Gamma Equ new [Re: Asbytec]
      #6118954 - 10/05/13 12:25 PM

Lol I don't even want to attempt this one.

Pete


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WRAK
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6119297 - 10/05/13 04:41 PM

Pete, this one would be a perfect target for your 8" Newton.
Wilfried


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azure1961p
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Re: Separation Gamma Equ new [Re: WRAK]
      #6119719 - 10/05/13 10:05 PM

Its funny, the other time I saw it in my finder when lining up on Delta and I just shrugged and thought "nahhhh too difficult". Ill give it a wing but if a guy can see it as fringey as Dave had at 16" - halving that would seem to be asking for disappointment though Im pleased to see Bills effort. I might try it but Id have a hard time reconciling it against a large cassegrain. I'm not trying to over inflate the difference but if its fringey to begin with - halving the resolution would seem damning.

Lol but Ill try Wil.

Pete


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R Botero
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6120994 - 10/06/13 05:22 PM

First clear night in weeks for me - in fact a whole month. Seeing started good with NEML of 4.5 but deteriorated by the time I got to 5 Equ. Result is that I could not split it at 450x with my 6" Apo.
Earlier in the session I tried Kui 97 as per Bill's post earlier in the thread. Got a rod-like structure with confirmed PA.


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: R Botero]
      #6121650 - 10/07/13 01:44 AM

I sympathize, Roberto. If I go back to the fourth post in this thread, you have already seen it. I hope you get the chance to observe again, not that I need this thing resolved, but I think you've already seen it.

I was out tonight as well, viewing Kui 97 with 100 mm to ascertain the field and be certain I had focused on the correct object the other night. I made a drawing of the field and find I did in fact, align correctly on Kui 97. Not to hold out, but I want another solid resolution before I star blabbing about it.... perhaps on a new thread. (Hint: white/sky blue kissing pair.... ?)


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Karl Fabian
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Re: Separation Gamma Equ new [Re: Asbytec]
      #6122288 - 10/07/13 12:07 PM

Quote:

I gave Gamma Equ a good hour tonight. No go at any mag from 310 to 390x. NELM about 4.5, seeing 7/10. Field stars down to 12th mag were visible, but the 9th mag companion was not. Not even a hint.




The Clear Sky Clock says good seeing tonight. If the Clock is correct, going to give Gamma EQL a try with my 8inch SCT. At 1" with a 4 magnitude difference it would seem to be beyond reach, but the WDS 2002 measures may very well be wrong after 11 years. In any case negative results are just as useful to the project as confirmation. Not only does the project seek to discover at what point is a target resolved but also when it is not.
I am doing most of my observing with a 90mm achro since they are looking for more reports with apertures 100mm and below. However this Gamma thing has me interested so I'll give it a try.
Most recent confirmation with 90mm was 23Aquilae (5.3-8.3, 3.2"). Secondary held steady at 123X with averted vision in my light polluted suburban back yard. Interestingly this target did not take high mag well. At 200x secondary not visible despite 1/2 hour scrutiny with perfectly defined airy disk with faint first ring in Pickering 8 seeing. Dropped to 123X and secondary popped up like magic. Visibility of faint secondaries with some targets can sometimes be improved if the airy disk has it's light more concentrated into a smaller area. An airy disk acts like any extended object by having it's light spread out more at higher magnification. Sometimes magnification is a balancing act.


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Asbytec
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Re: Separation Gamma Equ new [Re: Karl Fabian]
      #6122315 - 10/07/13 12:17 PM

Karl, great point on dimmer Airy discs at higher power. Forgot about that while bouncing between Chi Aql and Gamma Equ. Good luck with your Gamma Equ attempt. I hope you report success.

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azure1961p
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Re: Separation Gamma Equ new [Re: Karl Fabian]
      #6123355 - 10/07/13 06:50 PM

Quote:

Quote:

. In any case negative results are just as useful to the project as confirmation. Not only does the project seek to discover at what point is a target resolved but also when it is not.
.




EXACTLY! A negative result is still positive in the interest of collecting statistical data.

Pete


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Astrodj
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6123995 - 10/08/13 01:30 AM

I took another crack at Gamma Equ tonight. The seeing started out at Pickering 3-4 at 9pm local. I didn't bother with it at this point. Later, at about 11pm the seeing had improved steadily to Pickering 6 by my reckoning. I had just finished with Bu67 so I moved to Gamma Equ to see what I could see.

So as not to lead anyone on, I did not succeed.

I was using the 10" dob on an EQ platform. Magnifications used were 217x, 300x, 363x, 454X, and 600x. Time spent observing was in excess of 45 minutes. Gamma was well past zenith, but the seeing was much improved from earlier. I carefully examined the proper position angle for the companion and could not see anything that would suggest a sighting at any magnification.

After warming up on Bu67 I had hopes of better results from my first attempt, but I must say it looked about the same as last time. The seeing was a steadier than before, but no hint of the companion.

A tough nut to crack.


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Karl Fabian
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6123998 - 10/08/13 01:35 AM

Just got back inside after a futile attempt at Ganmma Eql with the 8 inch SCT. Seeing would not cooperate after spending 2 hours on it. It never got better than Pickering 5 with too many moving diffraction ring arcs and seeing artifacts. Simply too much light smeared around the ill defined airy disk to allow any hope of detecting a dim companion. The Clear Sky Clock good seeing prediction turned out to be a bummer. Hoping for decent seeing.

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Asbytec
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Re: Separation Gamma Equ new [Re: Karl Fabian]
      #6124791 - 10/08/13 12:11 PM

Sorry to hear it, Karl. Even with relatively calm rings the companion avoided detection in 6 inches aperture. One yes moment was quickly ruled out as seeing artifact. I'd love to observe this one, but Im loosing confidence in it. One more try, or two. Good luck to you on your next attempt.

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Karl Fabian
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Re: Separation Gamma Equ new [Re: Asbytec]
      #6124955 - 10/08/13 01:33 PM

This is definitely a tough one Norme. Any hope of resolution will require excellent seeing, especially with larger central obstruction scopes that throw more light into the rings.

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WRAK
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Re: Separation Gamma Equ new [Re: Karl Fabian]
      #6125418 - 10/08/13 04:51 PM

Bill, I basically take your positive report without any second thought as advertised data and reported aperture are within the realm of reason. What makes me curious are the described optical irregularities, especially the "broken" first ring with the (seemingly fainter than the ring) companion in the gap. I do not know any solid optical theory explaining this effect and I also miss empirical evidence - with good seeing I expect from a refractor and also a reflector without a spider for the mounting of the secondary a solid first ring and companions sitting on or in the ring do not "break" the ring at least as far as I remember. I will check this with my CO mask when I have the right conditions (good seeing and ~1.2" double with fainter companion in my field of view with reasonable altitude) - with zero CO the companion should sit within the ring and with increasing CO it should come into the ring and I expect eventually get "erased" by the then brighter ring. If the ring breaks and the fainter companion comes through then this would be the emperical evidence searched for - but I certainly do not expect such an effect.
Two negative reports from experienced observers with more than double the aperture you used also make a bit curious.
As far as I know this is your second positive report on Gam Equ - could you also provide your first one for comparison? The change of the parameters within one year would be minor even in a very fast orbit.
Wilfried


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azure1961p
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Re: Separation Gamma Equ new [Re: WRAK]
      #6125484 - 10/08/13 05:24 PM

Well Ive seen a fainter companion beside some doubles where the disruption of the rings momentarily uncovered it or provided more free space about it. On some doubles I would await for the disruption to occur so I could glimpse the companion before the ring fragments rejoined to form the complete ring again. Some times the rings appeared to be blown out of centricity . Of course they weren't blown away but the disruption seemed to give the effect. My guess here is that the the rings eminate from a seperate point source than the companion (however close) and this is how it is able to allow the rings to move about.

Even if every star in the field mimics the same ring disruption the star that happens to be where the rings have shifted or disappeared will shine through better because the effects from the primary diffraction pattern do not cancel out the light from neighboring diffraction patterns. Said another way, when the diffraction rings shift away or obliterate, the companion doesn't necessarily because its light is a seperate source altogether.

Sometimes in seeing as I stated earlier, less is more. My judgement isn't concrete here - Im open to other ideas but you can't expect one diffraction pattern to cancel out the light of another that isn't physically the same source.

Pete

Edited by azure1961p (10/08/13 05:25 PM)


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6126213 - 10/09/13 12:46 AM Attachment (30 downloads)

Wilfried,

As you requested, attached are my two confirmations from 2012. The differences; I called the companion topaz-yellow. This year, it appeared distinct blue-white. However, if you note the date of observations, Gamma AB was much lower in altitude when observed 2012, and that has an effect on color. (Dispersion.) I have noted this effect when observing many other pairs through the years/seasons.

What I saw this year is well enough documented in the illustration above. There was a diffraction ring of the primary (same color and near same intensity), "split" into a trifid (as illustrated). The companion appeared in roughly P.A. 270, exactly where the third arc of the trifid would have been. Comparing the observed secondary to the two other parts of the arc; the secondary "seemed" dimmer than the diffraction arcs. It could be an effect of hue (optical illusion), or and effect of magnitude and how the light behaves in my instrument. I can't explain the phenomenon according to theory. I can, and did, faithfully record what I saw. Usually, diffraction rings (in my instrument) are complete; 360º of arc, unbroken. I have seen a primary ring broken on more than one occasion. I've never given it more thought than an artifact of my instrument, or seeing, or whatever. (I was always more interested in what was inside the ring...)

I read all the posts on Gamma with interest. I'm everything from amused to dumbfounded few are seeing this pair. Let's remember, Roberto and Mark logged positive splits last year. I believe this is one case where aperture does not help the situation. The challenge is the glare and something to do with the behavior of light in the particular optical path being used.

I wholeheartedly believe in science. However, I am not a fan of "Scientism" - the cult which believes there is a theoretical explanation for everything. (Maybe someday...) Theory is little more than hindsight; it describes where we have been - in this case, what we have seen. Theory can aid us when viewing something new, but taken as law often becomes dogma. I hope my logs encourage others in the pursuit. Take what you need and leave the rest.


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6126216 - 10/09/13 12:48 AM Attachment (30 downloads)

Apparently, the first entry from 2012 didn't make it. Attached here.

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WRAK
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6126312 - 10/09/13 03:07 AM

Bill, thanks - consistent reports, especially as you noted in the first report the obviously smaller separation you noticed compared to the from Sissy Haas then advertised 1.5".
Wilfried


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azure1961p
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Re: Separation Gamma Equ new [Re: WRAK]
      #6126499 - 10/09/13 08:16 AM

Nice reports Bill - sounds like a nice Mak too so you had a high definition view. I've still not tried for this one yet - perhaps this weekend will be clear for me.

Pete


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David Gray
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6126574 - 10/09/13 09:06 AM Attachment (30 downloads)

Just to address this issue of glare with larger scopes and Gamma Equ B:

1). Going back to my first post on here I stated my use of an apodizer (a ‘neutral filter’: marked light reduction and diffraction rings minimized).

2). Uses of a binoviewer: i.e. >50% light-reduction and also in conjunction with the apodizer…..!

3). Use of an off-axis 6” mask.

4). I have since used a neutral density glass filter and also W#15 (light orange – poss. favour. B?) all of these separately and in various combinations – and no more certainty with B than I already reported in my first post.

Just recently a variable polarizer – always open to other ideas!

Also through thin cloud and also in twilight (easily swept up from Enif); if I thought standing on one leg would do it I’d give it a go.

I would also point out that B (reportedly) is not too different in magnitude to Titan: I have looked at this many thousands of times and Saturn has never managed to ‘glare it out’ in my scope. Even close-‘touching’ the globe (edge-on epochs) and low magnifications (down to x110 for the 16.3” D-K). In a good sky I can pick up Titan soon following half-hour after sunset; (summer twilight lingers long here at +54.7º lat.). As in recent apparitions: in pursuit of (with others) some colour effects. Also it is not that difficult to hold with part of the Moon in the field.

All this suggests to me I should be easily getting Gamma B at mag. 8.7 if it is c.1” or more distance in even moderate seeing.

I have yet to report – such as they are – my latest impressions, but I have put them on record with Fred during our PM exchanges and also an easy success with BU 730 (27 Psc.). With Gamma Equ I keep getting something in the ‘right’ place; but it simply does not come across as an undeniable star and that is my perplexity…… All I can guess is it is there shouting at/teasing me at some incipient level of detectability via the diffraction rings……….!!! If I got it I reckon it is pretty much fainter than Titan (similar colour tho’!). If it’s a variable then seems a strange one. I keep getting a faint smokey-orange hue with this ‘companion’/feature which seems to square somewhat with Kaler’s suggested late G/early K type; and have took care to eliminate atmospheric dispersion: B being in/near A’s red-zone.

Bill to be clear: I don’t say any of this with any sort of put-down/side-swipe. Neither did I come onto this thread with any such intention (bad timing maybe); merely putting my impressions/results. If you got it – then great job, in light of my struggles! But simply that I am experienced enough to anticipate and act upon the hazards that seasoned/veteran observers should be well aware of if they have properly developed their skills over years/decades! In short to report/represent, as you have done, what I truly feel I have seen in the eyepiece/s; with certain cautions/reservations as judged appropriate. This, in my view, separates the observers from the gazers.

For my part I await better than Pickering 7 – 8 in hope of certainty one way or the other.

With respect not sure about an occulter working near 1” separation as they can add effects that would possibly blur B out – not to say don’t try tho’!

Again an attachment with my best shots at possible orbits (with thanks to Fred for the data) and again including my impressions then (and still- last night).

With Respect,
David.

Edited by David Gray (10/09/13 11:10 AM)


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: David Gray]
      #6126640 - 10/09/13 09:56 AM

No offense taken, David. I'm reading it with great interest. I hesitate to say anything except what's in my log entry, because it is little more than speculation on my part!

Interesting info on occulting bar. I've no experience with one, but note what you say. Thanks.


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Cotts
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Re: Separation Gamma Equ new [Re: David Gray]
      #6126643 - 10/09/13 09:59 AM

The best thing that could come along for all of us would be a 2013 measurement by a professional observatory.

The primary star is a peculiar magnetic variable (see all the citations here) and one would think that, for mass determination reasons, there would be a need for up-to-date observations of the pair to calculate an accurate orbit.

Poke-poke.... any professionals out there who could look into it? Only a minute to slew a big scope over there and grab some speckle imagery....

Dave

Edited by Cotts (10/09/13 10:02 AM)


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WRAK
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Re: Separation Gamma Equ new [Re: Cotts]
      #6128342 - 10/10/13 03:31 AM

May be this could be also a challenge for Ed Wiley with his C11 - despite the large CO he did successful video imaging of BU720 with a separation of 0.57". So a resolution of a double with advertised separation of 1" (or even 1.13" given Bills observation report) should then be possible even with larger delta_m.
Ed?
Wilfried


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payner
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Re: Separation Gamma Equ new [Re: WRAK]
      #6137498 - 10/14/13 05:15 PM

I observed Gamma Equ on the night of 10/10/2013 with my Santel MK91 (228/3100) RuMak. Seeing was estimated at 4/5 with good transparency. It was cleanly split with a dark line between the primary and secondary using a Takahashi LE 7.5 mm for the best view. Both stars appeared cream with the secondary a bit darker. I estimated a PA at ~220.

Best,
Randy


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fred1871
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Re: Separation Gamma Equ new [Re: payner]
      #6137666 - 10/14/13 07:01 PM

Curiouser and curiouser... the range of observations of Gamma Equ.

Randy, how bright or dim did the secondary star look compared to the primary? I'm continuing to wonder if the secondary star is variable in brightness.


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payner
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Re: Separation Gamma Equ new [Re: fred1871]
      #6137758 - 10/14/13 08:03 PM

Fred: I estimate it was near magnitude 8, much dimmer than the primary.

Randy


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Cotts
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Re: Separation Gamma Equ new [Re: payner]
      #6137999 - 10/14/13 10:33 PM

Quote:

I observed Gamma Equ on the night of 10/10/2013 with my Santel MK91 (228/3100) RuMak. Seeing was estimated at 4/5 with good transparency. It was cleanly split with a dark line between the primary and secondary using a Takahashi LE 7.5 mm for the best view. Both stars appeared cream with the secondary a bit darker. I estimated a PA at ~220.

Best,
Randy




If you could, what estimate would you make of the separation?

This sighting encourages me to have a go with my 203mm/3100mm TEC MakCass at the Chiefland (FL) Fall Star Party. The legendary Florida seeing is calling me..........

Dave


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: payner]
      #6138038 - 10/14/13 11:02 PM

Thank you, Randy. I was about to confine myself to the looney bin. So now it's what, down by seven or eight, going into the fourth quarter?

Yes, any separation estimate would be helpful. Even proximity to a diffraction ring.

Fred, as soon as you hear from Mason; do tell!


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R Botero
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6138595 - 10/15/13 09:12 AM

It has to be a variable companion! (I hope). I'm almost sure I've seen it last year but no luck this year (because of poor weather really) since it has become observable again.

Roberto


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fred1871
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6138633 - 10/15/13 09:39 AM

Quote:


Fred, as soon as you hear from Mason; do tell!




I'll be very glad to let everyone know when data becomes available. I'm informed that a "request to observe" has been sent to several observers with access to suitable equipment (big scope plus adaptive optics).

Now it's a matter of waiting, and hope that at least one of the professional observers comes up with current numbers. That will settle whether the pair is closing or opening, where the separation has got to, and what the PA now is; those matters determined, we can look at possibilities for the secondary being variable etc. And I suspect this pair will repay measures being made more frequently from now for some years to come.


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payner
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6139589 - 10/15/13 06:40 PM

Quote:

Thank you, Randy. I was about to confine myself to the looney bin. So now it's what, down by seven or eight, going into the fourth quarter?

Yes, any separation estimate would be helpful. Even proximity to a diffraction ring.

Fred, as soon as you hear from Mason; do tell!




Bill: I estimate the separation to be near 1.1 seconds. I will look for the reference, but I seem to recall it stated the primary is variable, but with a magnitude difference of just several tenths of a magnitude. I don't know if that would make an appreciable difference in observing the secondary. I think steady skies and high magnification are requisites.

Best,
Randy

PS- I did a quick search and here is a note on variability https://en.wikipedia.org/w/index.php?title=Equuleus_%28constellation%29&r... (click on the link Equuleus). It appears this information was posted June 2008 and realize this site may not contain reliable information.


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azure1961p
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Re: Separation Gamma Equ new [Re: payner]
      #6139975 - 10/15/13 10:51 PM

Transparency too Randy - Im guessing. This is still on my to-do list. Love the avatar.

Pete


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6140127 - 10/16/13 12:27 AM

Thanks for the additional info, Randy. Your efforts are greatly appreciated.

I've also received an additional positive confirmation via personal message on this pair. It was quite detailed, however the observer requested to remain anonymous. I was not the only one on this thread who was sent the report, so some of you know what I'm referring to.

Once again truth suffers due to arrogance and the will of human ego.

Ever Onward, ~ Bill


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fred1871
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Re: Separation Gamma Equ new [Re: payner]
      #6140185 - 10/16/13 01:32 AM

Randy, there is also a Wikipedia item specifically on Gamma Equulei; and the references cited in that may be of interest to those wishing further information, particularly on the unusual primary star.

Jim Kaler also has a brief item on Gamma Equ available online. As one would expect, given the author, a useful summary, though again it's mainly about the primary star.


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: fred1871]
      #6140217 - 10/16/13 02:02 AM

Ah yes, down the well trodden path once again.... If you want truth; consult Wikipedia.

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fred1871
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6140224 - 10/16/13 02:20 AM

Bill, I obviously pointed to the references cited in the article, rather than the article itself. The references are to science papers. Those I thought might be of interest.

Those papers and the studies they represent won't always come to the same conclusions. Science is like that - finding a path through the forest, which can involve byways, and even paths that lead nowhere, on the way to reaching a clear view eventually. That's why science requires openly presenting evidence and discussing that evidence.


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WRAK
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Re: Separation Gamma Equ new [Re: fred1871]
      #6140287 - 10/16/13 04:41 AM

Excellent seeing seems paramount for resolving such a close binary with delta_m of 4. Already minor side effects may make all efforts even with larger apertures futile it seems.
I have taken the liberty to include the observations of Mark (203mm for 1"), Bill (178mm for 1.13") and Randy (228mm for 1") in my data set of limit observations as they are reasonable given the advertised data and wait for professional measurement for confirmation.
Roberto mentioned earlier splits with 152mm - this seems with the current "evidence" a tad optimistic and would require a somewhat larger separation which may have been given in the past but probably not now.
The so far negative reports with ~400mm apertures and very small CO are still somewhat disturbing - should have been an easy resolution with the given data and the mentioned reasonable good seeing.
Wilfried


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azure1961p
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Re: Separation Gamma Equ new [Re: WRAK]
      #6140385 - 10/16/13 08:00 AM

I'm curious what Cotts comes up with in Florida. This is becoming quite the enigma . Bill apparently you have spearheaded the medium aperture success here (of which I still cower from) and the subsequent reports if others support your finds which is a good thing. If I luck out with a night off of great seeing with my 8" Ill give it a gander but I've kinda shelved till till be ct summers balmy excellent seeing bows in again.

Pete


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R Botero
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Re: Separation Gamma Equ new [Re: WRAK]
      #6140386 - 10/16/13 08:00 AM

Wilfried

Note that my suspected split with a 6" over a couple of nights was last year in November. I have not been able (even to observe) this Autumn.

Roberto


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WRAK
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Re: Separation Gamma Equ new [Re: R Botero]
      #6140440 - 10/16/13 08:51 AM

Roberto, hope for a perfect night within the next 2 weeks for you - Gam Equ is still about 48° high for your location but will soon decline below 45° demanding some tribute to extinction.
Wilfried


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: fred1871]
      #6141015 - 10/16/13 02:12 PM

Thank you Fred. I quite agree with you. That's exactly why I'm posting my observations in the face of everyone's puzzlement.

Last night, I was discouraged that an observer with enthusiasm for the subject, good equipment, etc., took the time and trouble to resolve the pair over several nights... and then sends me a PM saying he didn't want to post his findings.

Anyway, I received another PM from him today and he gave permission to quote from his observation. Which I will - later.

As far as variability, my intuition is that there may be something to it. I will read these articles when I can. What I have read states the primary is an unusual, highly magnetic variable, but no variability has been detected in the visible light spectrum. (We're talking professional measurements here) My feeling is, if changes are taking place in the system, might not some form of interaction between the pair cause the secondary to at least appear variable?

Yes, I know.... We need professional measurements.


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payner
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6141364 - 10/16/13 05:41 PM

Quote:

Transparency too Randy - Im guessing. This is still on my to-do list. Love the avatar.

Pete




Hi Pete: Yes, transparency was very good that evening, but steady skies are the "treat" with such doubles.

Thanks for the nice comment on the avatar. I purchased this handmade Russian Mak from a friend who purchased it new. I've had it about six years now; other telescopes have come and gone, but this one has remained.

Best,
Randy


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payner
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Re: Separation Gamma Equ new [Re: R Botero]
      #6141751 - 10/16/13 08:37 PM

Roberto: It looks favorable here for observation on 10/18. I plan to use a 152 f/8 refractor on Gamma Equ. I am not expecting to get a split, but the observation will be interesting to me. I look forward to reading the results of your efforts with a 6" telescope.

Best,
Randy


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: payner]
      #6141917 - 10/16/13 10:04 PM

Following is the observation sent to me via PM by John, from Western France;

"I took a look at Gamma Equ a few weeks ago when the weather was warm, calm and still and the seeing very stable with good transparency. Given all the negative reports, I was very suprised to see the companion and it wasn't difficult at 320 - 400x. The view was almost exactly like the left hand one in the Pdf, which Bill posted on the 27th of September, except that the diffraction ring was visible most of the way round, save for a break where the companion was (the companion was slightly outside of the diffraction ring). I went back to the star the following day when conditions where the same with an identical result.
Now, here's the rub: the weather changed to slightly less stable skies and a gentle cool breeze and the next time that I tried I couldn't see the companion at all! I mean not even a hint... This suprised me so much that I even re-checked to see if I had the right star in the field. Anyway no luck that night at any power.

I have no Idea why people with larger (or similar) apertures and more experience are failing to see this one but I would guess it's something to do with the companion being so close to the diffraction ring and of just the right intensity to vanish into it in less that excellent seeing."

-John followed up with this, today;

"By the way, I'm happy for you to quote from my report if you like."

It should be evident this pair is achievable with medium apertures in the 6"- 10" range. Certainly larger apertures are capable of much finer resolution. Unfortunately, they achieve their theoretical potential less often due to atmosphere.


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Bill Boublitz
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6141928 - 10/16/13 10:08 PM

Forgot to include relevant information listed elsewhere in the letter;

"I use a very good Meade 178ed, .... eyepieces used were Zeiss jena orthos and 8mm Paradigm."


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azure1961p
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6142061 - 10/16/13 11:37 PM

Bill thanks for the clarification of accounts. Hats off.

Pete


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fred1871
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6142134 - 10/17/13 12:36 AM

Good to see that we have more observers trying this double. John's report, similar to Bill's as he points out, can be added to the database.

However his suggestion about why larger apertures have failed to see the companion doesn't explain that - because as the aperture changes, the position of the first and brightest diffraction ring changes while the position of the secondary star does not change. So with the companion at, say, 1.13" (Wilfried's estimate from Bill's drawing), a 16-inch or 24-inch telescope will have the first diffraction ring much closer to the disc of the primary than a 7-inch telescope, so the star image won't be near to or caught up in that ring.

And for 16-inch and 24-inch scopes, for which size telescopes we have reports, the position of the secondary star will lie outside the 2nd and 3rd (dimmer) diffraction rings as well.

So, the explanation will be found elsewhere. Atmospheric seeing will be more obviously detrimental to large apertures than smaller ones, but some of the reports from observers using larger telescopes address that issue, both by reporting on atmospheric steadiness, and giving examples of other difficult pairs successfully observed at the time, where more recent data can provide a benchmark.

The puzzle continues.


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WRAK
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Re: Separation Gamma Equ new [Re: fred1871]
      #6142249 - 10/17/13 03:26 AM

Strictly personal comments to John's report: If the advertised data for Gam Equ is only near reality than it is certainly not "not difficult" at all with 178mm - gap in the first diffraction ring or not. That a slight change in conditions made the easy resolved companion disappear would then be very remarkable if it is not difficult.

One possible szenario for such a diversity of positive and negative observations reports was already mentioned elsewhere: The companion of Gam Equ is may be a very fast changing variable - easy for 178mm one day and invisible for 400mm the next day.
Wilfried


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Cotts
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Re: Separation Gamma Equ new [Re: WRAK]
      #6142674 - 10/17/13 10:52 AM Attachment (5 downloads)

Concerning the variability of Gamma Equ A. Sky Safari gives this little tidbit.... No mention is made of the variablity of B.

interesting: The period of A's variability is 12.5 minutes!

I still feel my failure with 400mm of aperture is because the seeing was never good enough at OkieTex... I have some confidence that in the much better Florida seeing I will do better with my TEC 8"...

Dave

Edited by Cotts (10/17/13 10:57 AM)


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WRAK
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Re: Separation Gamma Equ new [Re: Bill Boublitz]
      #6143055 - 10/17/13 02:14 PM

Quote:

... observation ... John ...

"...the companion was slightly outside of the diffraction ring..."




Tried to translate this into numbers regarding separation - and this made me aware of a miscalculation for Bill's observation - should be simple enough but I managed to do it wrong. Therefore again the calculation in detail:
Size Airy disk with 550nm for 178mm with zero CO = 1.55". Separation for a companion sitting directly on the first diffraction ring with ~0.3 CO is therefore 1.55/2/1.22*1.61=1.02" (and not 1.13" as calculated before).
Same calculation for John assuming the size of the spurious disk for a +9mag star being 30% of the Airy Disk:
1.55/2/1.22*1.635+0.3*1.55/2=1.04+0.23=1.27" plus some space for the term "outside" may be 0.1" giving in total 1.37".
Sorry for the miscalculation. Hope I did it this time better.
Wilfried


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WRAK
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Re: Separation Gamma Equ new [Re: WRAK]
      #6144255 - 10/18/13 04:31 AM

To point out the obvious: Even the most confident positive reports on Gam Equ result in a puzzle - two observations with 178mm: One with the companion sitting directly on the first ring (or in a gap of the ring), the second with the companion sitting somewhat outside of the first ring (the slight difference in the diameter of the first ring for scopes with and without CO can be considered as too small to be visually relevant here - especially as the ring with CO is the smaller one).
Wilfried
PS: With the companion outside of the first ring with 178mm the resolution should really be not this difficult even with smaller aperture and with ~1.4" separation even the 152mm of Roberto come again into the realm of plausibility


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azure1961p
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Re: Separation Gamma Equ new [Re: WRAK]
      #6144410 - 10/18/13 08:45 AM

I'm looking forward to Cotts results in Florida.


Pete


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David Gray
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Re: Separation Gamma Equ new [Re: WRAK]
      #6146090 - 10/19/13 05:37 AM Attachment (27 downloads)

With another clear night in prospect I delayed posting my Oct 15th good view but passed on a preview (minus graphics) of my impressions via PMs to Wilfried & Fred.

I had pretty much decided to leave it alone as other observing matters were being sidelined. Last night [15th], however, was the first clear for some days, and very good seeing, so I thought I’d give it another go – just to get a look at something…..!!

Again I got the impression of a smokey-orange speck involved/impinging with the first ring: see text accompanying a graphic

To stick my neck out and give my best estimates on this date: mag. 9.5-10; sep: 0.55”-0.65” ; p.a. 200º-220º. If it is that close then it could well be 8.7 but looking fainter/overwhelmed by proximity.

What I contemplate posting is some thoughts on possible variability of the companion. Perhaps not that unusual a variable: an eclipsing one comes to mind; possibly a W UMa type. If this had a period close to 1 day (or even 0.5 day) then it could be that we from our respective locations would be catching it at a particular phase – me conceivably when it is near a minima??! A 0.5 day W UMa EB would fit with a G-K dwarf also.

Looks like some big-scope guys might sort it soon: and if its grossly away from what we are reporting then we have some issues to address – but I can only report what I believe to be seeing!

[Further PM (extract) to Wifried/Fred] I had further good views last night [17th] but after initial near convincing views with a 285mm square aperture mask and in particular when adding a W#15 filter. All I can say as the seeing got to 8/10 I was less persuaded. Then with full aperture it was doubtful to gone in the best moments; with this latter if it was there it was very tight-in; same PA spread though! This was spread over some 3 hours - maybe I caught during a fade.

The square mask gave a very neat Airy: rings subdued similar to the apodizer! Little change evident as regards the disk size: I suppose that the effective resolution would be determined by the diagonal of the square (403mm) which seems borne out by the disk similarity. How the 79mm CO figures with this is outside my knowledge! Further the mask + filter gave me a near pure split of Delta Equ with x535 – clearer than I got it on the 15th (on the graphic to be posted).


I was going to sit a while on this latter report, pending more checks (mask); but a showery regime is setting in here for some days they forecast.....

As long as I keep getting less positive views with improving condtions I have to remain guarded. Maybe the theme of Pete's thread: "Seeing - when less is more?" touches on my experiences?!

David.

Edited by David Gray (10/19/13 06:07 AM)


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David Gray
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Re: Separation Gamma Equ new [Re: David Gray]
      #6146094 - 10/19/13 05:48 AM

Variability of Gamma Equ B: I followed up with these thoughts: elaborated further here

Just as an afterthought on the companion being a W UMa type: presumably we would have two fairly equal stars. This would imply that they were even later than early K – nearer to M perhaps. A stronger ruddy hue then indicated.

I have had some others [family/friends] view my “smokey-orange” (on the graphic) and some are calling it lilac. This brings to mind some old descriptions of Eta Cas B – a red dwarf, as purple, (a lovely red-orange to me). This seems counterintuitive but a shorter step to blue than orange/red. Similarly with red dwarf pair Mu Her BC “cerulean blue”; but again simply red-orange to me Though I feel where less light is involved a seemingly grey comes can be (mis)interpreted as bluish purplish/lilac?.

More thoughts: if Gamma B is a red dwarf pair, do they occasionally flare [YY Gem/Castor C]? As they close to the [intensely magnetic-field of the] primary are they stirred to more activity?!

Time to lie down now…….. or contact Kaler!

The primary is classed as a low-amplitude variable – perhaps hidden in the ‘noise’ is a contribution of B’s possible variability.

It might be worthwhile to see how the inevitable scatter of Gamma B's estimated magnitudes compares with those of similar doubles?

Strange results in the past have sometimes been found to have a cause not anticipated. The 1940/50s colour photometry of Io comes to mind: “ Variable colours”……. “exceptional behaviour of Io” – and now we know why……!!.



Edited by David Gray (10/19/13 06:50 AM)


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Cotts
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6150310 - 10/21/13 05:51 PM

Quote:

I'm looking forward to Cotts results in Florida.


Pete




Oh, the responsibility........

During my week at Chiefland Gamma Equ will be transiting around 8:30EDT in the evening and be at 70 degrees altitude in the south, high enough to get really good seeing and transparency....

Thanks to Norme and Wilfried I now know that for my TEC 8-incher the following numbers apply, to reasonable accuracy.

Radius to first minimum of diffraction pattern -- 0.62"
Radius to first maximum of diffraction pattern --0.90"
Radius to second minimum ------------------1.36"
Radius to second maximum------------------1.53"

So, if GammaB Equ is anywhere from 1.0" or more it will lie in pretty much dark sky for me, assuming the second ring is virtually invisible, which it should be for a 5th magnitude star....

I will be bringing eyepieces for very high power: 9mm orthoscopic (344x), and my 6mm-3mm Nagler zoom giving 517x, 620x, 775x and 1033x at the click-stops.

And a 1.8x Barlow.....

Dave

Edited by Cotts (10/21/13 05:52 PM)


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WRAK
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Re: Separation Gamma Equ new [Re: Cotts]
      #6151127 - 10/22/13 06:08 AM

Dave,
if advertised data and observations of Bill is to be confirmed then you should get a nice diamond ring with the companion sitting on the first ring. If John reported correct then it would be an easy resolution in the second minimum. Can it be this easy?
If David's report reflects reality you will get a negative result but to confirm it you will need another scope.
Wilfried


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Asbytec
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Re: Separation Gamma Equ new [Re: Cotts]
      #6151141 - 10/22/13 06:34 AM

It would be interesting to know if you could nab Gamma Equ visually between the rings (or where ever it is) or image it. I think the data above would help us figure out where it is and why it's so hard...and if between the rings makes detection easier. I'm curious to know if the dark space makes detection easier even if the rings nearby are not seen. Something keeps the companion hidden: glare or interference?

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banatop
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Re: Separation Gamma Equ new [Re: WRAK]
      #6151856 - 10/22/13 03:11 PM

Quote:

Dave,
if advertised data and observations of Bill is to be confirmed then you should get a nice diamond ring with the companion sitting on the first ring. If John reported correct then it would be an easy resolution in the second minimum. Can it be this easy?
If David's report reflects reality you will get a negative result but to confirm it you will need another scope.
Wilfried




Actually Wilfried, I said (as quoted by Bill)"The view was almost exactly like the left hand one in the Pdf, which Bill posted on the 27th of September, except that the diffraction ring was visible most of the way round ,save for a break where the companion was (the companion was slightly outside of the diffraction ring). I went back to the star the following day when conditions were the same with an identical result."

The companion was very close to the first diffraction ring and gave a very nice diamond ring effect as drawn by Bill. As I said, my observation was almost identical to Bill's and It wasn't difficult due to the seeing. ( Please note that there is a subtle but real difference between the terms "easy"which I didn't use and "not difficult" which I did.) The reason that I said it was "not difficult" is that the companion was simply there and required no special effort to see it, certainly due to the seeing. Anyway, good luck to Dave and I'm sure, given excellent seeing, he'll succeed. Best, John


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WRAK
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Re: Separation Gamma Equ new [Re: banatop]
      #6152993 - 10/23/13 05:30 AM

Quote:

... the companion was slightly outside of the diffraction ring...




John, thanks for clarification - I then misinterpreted your quote above as may be slight but in terms of separation distinctive deviation from Bill's observation of the companion sitting directly on or in a gap of the first diffraction ring.
Wilfried


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azure1961p
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Re: Separation Gamma Equ new [Re: David Gray]
      #6153314 - 10/23/13 10:07 AM

David,

I think you nailed it well when proposing that stars seeming toward a shade of grey can be confused with lilac or blue even though its orange. The lack of a certain or brighter coloring allows it to be more subject to color contrast illusion effects. I actually learned color illusion effects from Alan MacRobert in one of his star hop articles I had at the scope one night . His mentioning a neighboring star to a yellow was lavender and Ive seen the suggestion of that there and elsewhere since. A greyish star that fan seem to go either way in color is subject to that Ive found - particularly when its faint. But it needs yellow to kick it off. On fairness MacRobert wasn't implying lavender stars but merely the effect .

This is a vexing star to be sure .


Pete


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Cotts
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Re: Separation Gamma Equ new [Re: azure1961p]
      #6153425 - 10/23/13 10:53 AM

I'll have a stab at the colours I see as well. Stars down around 9th mag or fainter pretty much all look pale green-white to me, probably because that's the colour our eyes are most sensitive to....

I will also do a video and lucky imaging too.

While I'm in chiefland I may even look at some other objects.....

Dave


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Cotts
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Re: Separation Gamma Equ new [Re: Cotts]
      #6165959 - 10/30/13 09:11 AM

Two nights in chiefland and the seeing has not been better than Pickering 6. I've spent some considerable time on it and no hint of a companion at 391x. Higher magnifications are not supported by the seeing. The diffraction rings are moving quite a bit, sometimes gathering on one side of the spurious disc, sometimes flaring into fuzz and sometimes very symmetrical and still ( but never for long enough times to really stare at it...)

I made three videos (varying exposure and ISO) for lucky imaging and will be processing them today.

The dew here is biblical in quantity.....

Dave


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Asbytec
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Re: Separation Gamma Equ new [Re: Cotts]
      #6166027 - 10/30/13 09:43 AM

Hurry up, will ya? (In jest )

Thank you for taking the time and effort. Hope you got something.

Are you taking requests? Got a few...


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Cotts
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Re: Separation Gamma Equ new [Re: Asbytec]
      #6166194 - 10/30/13 11:25 AM

Sure, request away!!

Dave


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Asbytec
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Re: Separation Gamma Equ new [Re: Cotts]
      #6166207 - 10/30/13 11:31 AM

BU 9AB, 1 and 13 Del.

Kind of jivin with ya waiting for your results. But, hey..

Saw your diagonal thread, too.


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Cotts
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Re: Separation Gamma Equ new [Re: Asbytec]
      #6168013 - 10/31/13 09:27 AM

Well, it appears to be a bust, weather-wise. Last night was very hazy until well past 1:30 am. I did try to observe the two Delphinus pairs but the air was very unsteady again, worst of the three nights here.

My 'lucky imaging' results on Gamma Equ showed no hint of a companion star.

Tonight iappears cloudy and Friday night and most of Saturday there will be thundershowers, by all accounts. Thus, I will be leaving friday at noon...

It is nice to be sitting here in shorts and a t-shirt, though...

Dave


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Asbytec
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Re: Separation Gamma Equ new [Re: Cotts]
      #6168144 - 10/31/13 10:33 AM

Well, I am sure we all appreciate your attempt. I do. Maybe it's a clue to how difficult these are.

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Re: Separation Gamma Equ new [Re: fred1871]
      #6176056 - 11/04/13 06:54 PM

Quote:

Note the details I and others gave in discussing the pair in the earlier thread. The separation is now pretty definitely LESS than 1.0".




this makes a useful point. it never hurts to mention the epoch of measurement (or catalog), or at least be aware that the source doesn't give the epoch.

many double stars are "fixed", and most barely change over decades or more, but improved measurements can change the picture. it never hurts to know the epoch.


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Re: Separation Gamma Equ new [Re: drollere]
      #6655522 - 07/27/14 04:52 PM

In a few weeks I will be up in the mountains with the possibility to use a Meade LX200 12" for a look at Gamma Equ under a black and hopefully clear sky. If seeing is cooperative resolution should be possible and if 1" separation is correct the companion should sit centered on the second diffraction ring. With 1.1" separation the companion should sit outside on the second ring and with 0.9" inside. Looking forward to this opportunity. Regrettable the large CO of ~0.35 does not allow the use of masks to determine the limit aperture to resolve Gamma Equ under the given conditions.
Wilfried


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azure1961p
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Re: Separation Gamma Equ new [Re: WRAK]
      #6656074 - 07/27/14 09:41 PM

Its nice to see this double thread come up again here. By the time I was considering a look the jetstream was beginning to shift south again. That said and based on all accounts from different CN observers with the same or substantially more aperture than I, Im not expecting much with my own attempts . Ill give it a good summer seeings try however.

Good luck Wilfreid.

Pete


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fred1871
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Re: Separation Gamma Equ new [Re: WRAK]
      #6656196 - 07/27/14 10:30 PM

Now you've done it, Wilfried - mentioned again (or raised from the dead?) the one who must not be named.

Less satirically - Brian Mason at the USNO (keeper of the WDS) told me recently that a new measure of Gamma Equ has been made, but the raw data is not yet reduced. He intends encouraging those who did the work to reduce the data to a final measure - separation and angle - sooner rather than later. That way we won't have the situation that occurred previously, when the measure made in 2002 was not published until many years afterwards.

So, there's a late-2013 measure in the pipeline, but we'll have to wait, unfortunately, for it to emerge.

For now I'm still expecting the pair to have continued closing since 2002. Anyone re-reading this long thread can see why I'm reading it that way (past history of the double, Dave Gray's observations, etc). But, whatever the result, it will be interesting. More interesting, if indeed this binary is moving into the closest part of the orbit.

I'm not convinced a Meade 12-inch SCT is the preferred telescope type for this double. Cotts 16-inch Zambuto with small CO, Dave Gray's 16.3-inch DK with small CO, seem to be more likely useful as weapons of attack. Even so, report what you find. The right mountain location might help; some mountains don't.

Hmmm.... a pity, Wilfried, that you can't get a telescope such as the 27-inch (69cm) Vienna refractor to use for this exercise. It would appear to be the ideal type of telescope for the attempt. Big enough (probably), and no CO....


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David Gray
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Reged: 08/06/12

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Re: Separation Gamma Equ new [Re: fred1871]
      #6656357 - 07/28/14 12:15 AM

I have confided off-forum with Pete (Azure) about my continuing quest with this. Still the same certainties/uncertainties.

A pair of new eyepieces (x610/x490+focal reducers/x890+extenders) are giving very nice clean views at those powers.

Might even say I lean a little more to the certainty side since recommencing the double in early June. All I can say if it is anywhere near 1” I just do not understand why I find 27 Psc so easy above Pickering 4 and 85 Peg 7 and above but Gamma Equ still toys with me in my, so far, best views at Pickering 8.

By and large little to add to those graphics depicting my best impressions I submitted earlier in this thread. Sticking my neck out my best impressions: 190º-220º, 0.4”-0.5” mag. 8.5-9.0. Comparing my experience with 85 Peg I would conjecture that Gamma B is on or just proud of the 1st ring and perhaps very slightly fainter than it. Often when I feel/sense (!) it is showing there is a slight thickening of the ring there in an arc of some +30º.

As a control I have been viewing single stars of similar brightness, such as Gamma Del – two single stars that bracket Gamma Equ; and especially Xi Peg. The brighter of these, if there is an optical effect present with Gamma Equ, might be expected to show such more clearly. I have also on occasion used Delta Equ which is elongated at best in my scope currently.

As I say my neck is out and if the new measures are way off my impressions I may well confine myself to planets in future! After my struggles last season with Gamma it was refreshing some nights following on with something easier – seeking detail on Uranus!!

Not a hint a couple of hours back with Gamma E in P/6 (too near houses maybe) but Uranus was slightly more obliging in A/II-III!

Dave.


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fred1871
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Reged: 03/22/09

Loc: Australia
Re: Separation Gamma Equ new [Re: David Gray]
      #6656468 - 07/28/14 01:45 AM

Dave, thanks for the new observations. And, consistent with previous ones by you, with the useful checking by comparing with other stars and other doubles.

Your graphics from late last year (earlier in this thread) are I think sufficient indication that Gamma Equ is going to be closer now than it was in 2002. Simply plotting the measures, as you did, shows a pattern, including the expectable scatter of old measures on what even then, when it was wider, would be a somewhat difficult double to measure given the large delta-m. The later measures suggest a closer pair, though how close - 0.8"? or 0.6"? or 0.5"? remains uncertain from the graphics. Your observations suggest it's likely in that range. But a new measure with a very large scope using the more accurate techniques now available - speckle or adaptive optics - should give a clear measure of the change. In this case, adaptive optics appears more likely, given past failures with speckle - large delta-m is problematic for that technique, and the failure might suggest delta-m even larger than recently suggested (variability??).

Unfortunately, this pair has been semi-neglected in recent decades, due to not showing much movement over short periods in the past. This sometimes happens - doubles reach a part of their orbit where change in our line of sight becomes quicker, and what needed a measure once in twenty years to record a small change, starts showing obvious change in five or ten years.

Okay - we'll see what other observers find, while we wait for the big-scope result.


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