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Separation Gamma Equ

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#151 Cotts

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Posted 23 October 2013 - 09:53 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

#152 Cotts

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Posted 30 October 2013 - 08:11 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

#153 Asbytec

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Posted 30 October 2013 - 08:43 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... :)

#154 Cotts

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Posted 30 October 2013 - 10:25 AM

Sure, request away!!

Dave

#155 Asbytec

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Posted 30 October 2013 - 10:31 AM

BU 9AB, 1 and 13 Del. :)

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

Saw your diagonal thread, too.

#156 Cotts

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Posted 31 October 2013 - 08:27 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

#157 Asbytec

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Posted 31 October 2013 - 09:33 AM

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

#158 drollere

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Posted 04 November 2013 - 06:54 PM

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.

#159 WRAK

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Posted 27 July 2014 - 03:52 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

#160 azure1961p

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Posted 27 July 2014 - 08:41 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

#161 fred1871

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Posted 27 July 2014 - 09:30 PM

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

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....

#162 David Gray

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Posted 27 July 2014 - 11:15 PM

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.

#163 fred1871

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Posted 28 July 2014 - 12:45 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.

#164 David Gray

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Posted 28 July 2014 - 02:40 AM

Yes Fred I still ponder the possible variability explanation - a short period late K early M dwarf W UMa system would be fascinating - maybe even the occasional flare........ :grin: :question:

#165 azure1961p

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Posted 28 July 2014 - 10:42 PM

Its too bad we haven't other observers with at least 12" aperture to have hand at it. I know we had one observer reporting glimpses with a 10" newt. - having seen the numbers in this and reports though - I think even 12" is optimistic.

With all the large dobs out there these days its regrettable we don't have these folks here - and with potentially amazing reports.

Pete

#166 fred1871

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Posted 28 July 2014 - 11:40 PM

The large Dobs would need to be planetary-optimised scopes; otherwise I suspect the users would find, as someone else did, that an 8-inch f/9 can outperform a 10-inch f/5.

A lot of the big dobs I've seen were not good double star scopes. They were fine for faint fuzzies. The better ones these days are like the scope Cotts mentioned using - very good optics (Zambuto), small OC, etc. Now if only his Zambuto mirror was f/8 instead of f/5 :grin:

Despite it being still controversial, long-f-ratios, all else being equal, do seem for whatever reasons to give better images in some respects. That improves the chance of seeing the more elusive double star secondaries.

This one is very elusive, and the possible variability of the companion can't be ruled out. Looking through the estimates and measures of its brightness, there's a bigger range than usual - the Tycho number, giving 4.0 magnitudes, is about the smallest in visual light - for the 2002 measure 3.8 in red or near-IR. Because the secondary seems to be orange, and the primary is white, that will expectedly reduce the delta-m in R or near-IR.

Interestingly, Hipparcos disagreed with Tycho more than usual with Gamma Equ - Hipparcos gave 4.25 mags difference, versus Tycho at 3.99.

Early 20th century observers were typically in the 6 to 7 magnitude difference. Even allowing for the usual effect of much fainter, close companions looking dimmer than they really are, that might suggest a larger delta-m than 4.0, at least some of the time.

We shall see what comes out of further studies of this unusual object.

#167 WRAK

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Posted 18 August 2014 - 03:37 AM

My first attempt with the 12" Meade LX200 did not work out as I had hoped for.

While the sky in the mountains is spectacular dark with NEML better than +5.5mag and TML beyond +14mag the seeing was only moderate fair.

After getting somewhat familiar with the parallactic GoTo mount (had expected a fork mount with the option of manual control) I located with some difficulties Gam Equ (no direct GoTo target with this rather old software version available here, so I had to use faint galaxy NGC7015 as target and go then ~1° east and then ~1° south to have Gam Equ in my field of view).

 

With a magnification of x430 I got first hints of a diffractions pattern and with x610 a very bright pattern with 3 to four visible rings but very unstable. It was then impossible to find any hint of a faint companion as expected between the 1. and 2. ring. May be a higher magnification might have been useful but I had no eyepiece with less than 5mm focal length available as I did not expect such a need.

 

Used then the Meade for the kind of observations it seems most usefull - deep sky objects like globular and open cluster. Especially M11 (wild duck cluster) was spectacular - so it was a nice observing session even if "only looking at nice targets" without any agenda is not my preferred session mode.

 

Hope for another clear night to try again Gam Equ and do maybe some more double star observing.

Wilfried



#168 R Botero

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Posted 19 August 2014 - 07:10 AM

Enjoy the mountains Wilfried!  :FarmerRon:  Too bad on Gamma Equ  :p

 

Roberto


Edited by R Botero, 19 August 2014 - 07:10 AM.


#169 WRAK

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Posted 19 August 2014 - 10:20 AM

Tried last night again. Early in the evening clear sky so I opened the roof of the small observatory to cool down the scope and attached the dew cap. When the sky got black I started my session. Two star alignment plus two additional calibration stars took their time and when I had finally Gam Equ in the field of view of my eyepiece conditions had deteriorated and within a few minutes the sky was cloudy. This was it. Today weather is rainy so this was my last chance.

 

Lessions learned:

- Not new but confirmed: Very dark sky is spectacular for the naked eye and binoculars but no guarantee for good seeing

- Simple equipment like refractor with Alt/Az mount has the clear advantage of shortest possible setup - else you are prone to waste valuable clear sky time with equipment issues

- Now I understand fully why easy to use tools for scope control like SkySafari are this attractive for observers with parallactic GoTo mounts.

 

So nothing new regarding Gam Equ but I enjoyed the moutains and had some nice days here.

 

Gam Equ will have to wait until end of September to come this season again in my field of view in Vienna and will stay here for about one month. Within this timeframe I should have the 200mm DK in use and have with it a realistic chance to resolve Gam Equ if the current WDS data is valid.

 

Wilfried



#170 R Botero

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Posted 21 August 2014 - 03:40 AM

Wilfried

 

I was out last night with the TEC 250 f/20 Mak and had a go at Gamma Equ.  Could not see the companion although there was, as per my previous observation with the 6" f/7.5 refractor, a bump in the first diffraction ring in the direction of the assumed secondary.   Conditions last night were average with good transparency and very good seeing early in the evening but by the time Gamma Equ had cleared my neighbours' roof fully, seeing had deteriorated.  I shall be able to observe Gamma Equ weather permitting for some weeks now so will be praying for that night of perfect seeing.  The 10" Mak can certainly take in magnification without breakdown.

 

Roberto



#171 WRAK

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Posted 21 August 2014 - 01:44 PM

250mm f/20 ... sounds interesting. The companion of Gam Equ should with 1" separation then sit exactly in the second minimum between 1. and 2. ring.

Wilfried



#172 R Botero

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Posted 21 August 2014 - 03:02 PM

Wilfried 

 

Well the 2nd ring was not clearly discernible by then as the seeing had deteriorated. But your expectation matched closely the bump in the primary ring I was seeing.

Roberto



#173 payner

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Posted 21 September 2014 - 02:01 PM

I observed this system 19 September 2014 with a 9" RuMak.  Skies were clear and seeing was estimated a Pickering 6, so not great but decent.  I used magnifications of 238, 396 and tried a ridiculous (given seeing) 596 on Gamma Equulei. My observations were negative, but I can't get this seeming enigma of a system out of my mind.  I will be attempting this again over the fall in hopefully better seeing.  I am hoping to confirm my observation of last October made in better seeing conditions; I suppose with all the additional observers getting negative results cast a bit of doubt in my own observation.  I want to encourage the 'group' to continue this quest.

 

Best,
Randy



#174 Cotts

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Posted 21 September 2014 - 03:23 PM

Sep 19 and Sep 20 at Okie Tex.  With my 202mm f/15.5 MakCass at up to 640x -  100% negative result.   Seeing both nights was 4-7 out of 10 Pickering and it was breezy.

 

I also tried 'lucky imaging' Gamma Equ with my Canon 60Da and got no hint of a companion.  Note that on one of the nights (20th) I visually split an 0.6" pair  and have decent video images of STF 2289 (1.22" delta 0.56 mags) and STT 338 (0.844" delta 0.17 mags).  I will be posting those images in another thread presently.

 

I've 'put the word out' here at Okie for Gamma Equ and 90 Her.  Let's keep at it!!!

 

Dave



#175 WRAK

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Posted 19 October 2014 - 03:56 AM

Still waiting for my 200mm DK scope and season for observing Gam Equ slowly passes by. Fred's remark about using the large refractor of the Vienna observatory lingers in the back of my head. Learned so far that this scope is currently not operable but I might be allowed to use a 300mm Clark refractor - again with some technical issues but at least in good shape optically. Will see ...

 

Last night I had again a look at Gam Equ with my 140 mm refractor without trying the impossible but to get familiar with the star field around Gam Equ and may be to resolve BU 71 (Gam Equ C). Was also not successful here (had this one resolved already a few weeks ago) but made a small sketch of the star field to compare with an UCAC4 star map and and the DSS image. Found to my surprise a +10.31mag fake star UCAC4-501-139884 about 23" north of Gam Equ not existing in my sketch and also missing in the DSS image. Just another riddle.

 

Wilfried

 

PS: Left part of the image is the UCAC4 star map with the stars part of my sketch labelled. Right part is the negative DSS image with identical orientation

Attached Files


Edited by WRAK, 19 October 2014 - 04:10 AM.







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