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kevin M13
sage


Reged: 03/07/09

Loc: Upstate NY
Frustrating Lyra Doubles
      #3953971 - 07/30/10 07:03 PM

I was out a few nights recently including last night with mixed results on some new summer doubles. One thing I love about doubles, is that I have been observing them for many years, and I still am seeing new ones all the time and some of them are very pleasant surprises.

Frustrating ones first from last night and previous 3 nights out. As a test, I started out with Delta Cygii. Could sense duplicity at 100x in my C11, but very tight split with companion as a tiny pinpoint at 200x so seeing was pretty good in my neck of the woods. No diffraction rings could be seen around Epsilon. Usually requires very steady night and lots of mag in C11 to see that.

OS 525- in Lyra, up to 700x last night in C11, and I could not see the B component. My reference NSOG lists this as a triple. The AC components are really nice though. Seeing P5.

B648 in Lyra caught glimpses of the companion last night in partial diffraction ring (arc's) at 500x at a PA I looked up after and verified, but I would want to see it again and cleaner than this to call it split. My reference lists this one as .7".

17 Lyra- no luck. I am quite surprised I can't get this given data in NSOG. Anybody know what the current sep is and has anybody gotten this one recently? C11, 500x.

On the bright side, I "discovered" Struve 2470/2474 the other double double in Lyra for the first time. I never looked at those before. What a cool set of doubles.

Clear skies,
Kevin


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Dave Mitsky
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Reged: 04/08/02

Loc: PA, USA, Planet Earth
Re: Frustrating Lyra Doubles new [Re: kevin M13]
      #3954069 - 07/30/10 07:47 PM

Quote:



On the bright side, I "discovered" Struve 2470/2474 the other double double in Lyra for the first time. I never looked at those before. What a cool set of doubles.






Struve 2470/2474 is perhaps my favorite multiple star.

Dave Mitsky


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blb
Post Laureate


Reged: 11/25/05

Loc: Piedmont NC
Re: Frustrating Lyra Doubles new [Re: Dave Mitsky]
      #3954155 - 07/30/10 08:49 PM

Yes I would agree with that. I think that Struve 2470/2474 are much more enjoyable to look at than epsilon Lyra (the double-double).

Buddy


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John Fitzgerald
In Focus
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Reged: 01/04/04

Loc: AR
Re: Frustrating Lyra Doubles new [Re: kevin M13]
      #3954208 - 07/30/10 09:25 PM

Quote:

OS 525- in Lyra, up to 700x last night in C11, and I could not see the B component. My reference NSOG lists this as a triple. The AC components are really nice though. Seeing P5. Clear skies,
Kevin




I have been looking for the close companion of OS 525 for some time in order to complete the AL Double Star Club list. No luck with my 6" refractor in the dome, but seeing has not been really good since I have been trying. Next time I am at the dark site with my 15" Dob on RT Platform, I will try OS 525 again. and bump up the power to maybe 500x or so. On unequal doubles, the smaller the central obstruction, the better. That's why refractors work so well on unequal, close pairs.


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Rich (RLTYS)Moderator
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Reged: 12/18/04

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Re: Frustrating Lyra Doubles new [Re: John Fitzgerald]
      #3954871 - 07/31/10 07:48 AM

I was able to resolve the "B" component with my 10" refl back in 2008. At 348x I could see it about 30% of the time. A difficult star to observe. The "A" "C" components are also cataloged as SHJ 282. (South and John Hershel)

Rich (RLTYS)


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John Fitzgerald
In Focus
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Reged: 01/04/04

Loc: AR
Re: Frustrating Lyra Doubles new [Re: Rich (RLTYS)]
      #3955018 - 07/31/10 10:10 AM

In excellent seeing (a big IF) with my 15" the "B" component of OS 525 should be steadily seen. I tried aome other pairs last night with similar magnitudes but wider separation and they were still difficult in the 6" refractor. These were Antares, Struve 2665, and Ho 131, the latter two in Delphinus. The comes of Ho 131 was not seen with any certainty, likely due to LP and bright moonlight. Might be better in a darker sky. Needs more contrast.

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rookie
Good Night Nurse
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Reged: 01/14/06

Loc: St. Petersburg, FL
Re: Frustrating Lyra Doubles new [Re: John Fitzgerald]
      #3955031 - 07/31/10 10:16 AM

A microfocuser is extremely helpful for viewing difficult doubles. It's a good reason to upgrade for anyone who has not made that step.

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kevin M13
sage


Reged: 03/07/09

Loc: Upstate NY
Re: Frustrating Lyra Doubles new [Re: Rich (RLTYS)]
      #3955039 - 07/31/10 10:26 AM

Thanks for the reports. I will get my refractor out as it has been a little while, and but I had been working with the more recently acquired c11 on a slew of doubles I was never able to get with the refractor, but since OS525 was a new attempt in general, I was still using the C11.

Persistence pays off though. Out for the 4th time with these among others, I met with some success.

B648 in Lyra, I verified what I saw the other night. 500X was needed and during moments of steadier seeing I could see the split on this estimating the PA WNW. This unequal is listed in my reference as 5.4/7.5 .7" sep. Not sure if this is accurate today.

OS525- no luck up to 700x. Just can seem to see the B component.

17 Lyra- Once I got to the right mag, I found it easier than B648. At 500x I could see the companion in similar orientation to 648. Seems much closer than the 3.4" my NSOG lists it at which is greater separation than delta cygnii which was easy at 200x. It lists the mags at 5.2/9.3 which is a greater difference than Delta which may be why.

Clear skies,
Kevin


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John Fitzgerald
In Focus
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Reged: 01/04/04

Loc: AR
Re: Frustrating Lyra Doubles new [Re: rookie]
      #3957099 - 08/01/10 11:47 AM

I am attempting to get a Moonlite focuser with the 8:1 fine focus. EDIT: Just bought the Moonlight refractor focuser with fine focus and lock on Astromart. It seems that STT 525 in Lyra (close to M57) may need more aperture and darker sky, which is why I am going to attempt it from my dark site observatory with the 15" Dob. That B component is pretty close and faint. Excellent seeing will also be required.

Edited by John Fitzgerald (08/01/10 01:31 PM)


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kevin M13
sage


Reged: 03/07/09

Loc: Upstate NY
Re: Frustrating Lyra Doubles new [Re: John Fitzgerald]
      #3957708 - 08/01/10 05:56 PM

Good luck John, let us know how you make out. I will keep trying. I bagged a bunch of new ones again last night in and around Lyra, but unfortunately 525 would still not yield.

Kevin


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John Fitzgerald
In Focus
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Reged: 01/04/04

Loc: AR
Re: Frustrating Lyra Doubles new [Re: kevin M13]
      #3961519 - 08/03/10 01:29 PM

Last night with my 6" Achro at 200x I saw the faint companion of 17 Lyrae in good seeing. Checked the PA later, and I was seeing it in the proper place (about 270 deg).

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C_Moon
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Reged: 10/23/09

Loc: Beneath the arms of Cassiopeia
Re: Frustrating Lyra Doubles new [Re: Dave Mitsky]
      #3978784 - 08/12/10 12:30 PM

Quote:

Quote:



On the bright side, I "discovered" Struve 2470/2474 the other double double in Lyra for the first time. I never looked at those before. What a cool set of doubles.






Struve 2470/2474 is perhaps my favorite multiple star.

Dave Mitsky




Saw this pair two nights ago for the first time. It is a gem! Thanks for motivating me to take a look.


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John Fitzgerald
In Focus
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Reged: 01/04/04

Loc: AR
Re: Frustrating Lyra Doubles new [Re: C_Moon]
      #3979448 - 08/12/10 06:38 PM

In my light polluted skies, I have difficulty seeing a companion thet is 10th mag or fainter when closer than about 20" to a 6 mag or brighter star. Not enough contrast due to LP; almost like observing near a bright moon. (6" Achro)

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geminijk
scholastic sledgehammer


Reged: 04/03/08

Loc: TN
Re: Frustrating Lyra Doubles new [Re: John Fitzgerald]
      #3980169 - 08/13/10 04:17 AM

17 lyrae - Found this tonight and was surprised at how easy it was to see. Secondary is dim and blinking a bit, but I could clearly see it with direct vision. LS 8 ACF w/14mm UWA 145x.

John


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Svezda
scholastic sledgehammer


Reged: 06/01/07

Loc: Texas
Re: Frustrating Lyra Doubles new [Re: geminijk]
      #5943741 - 06/27/13 08:11 PM

I have been searching for info on Burnham 648 (BU648 in the new form that unfortunately discarded the use of the traditional designations including Greek letters). I found this one completely by chance while looking around the region surrounding M57 with my 14.5-inch Teleport (Zambuto mirror).

I noticed with a casual glance with my Docter 12.5mm eyepiece (x130) that this star might be double, but I wasn't sure. I checked at x260 with a 2x Powermate and easily saw that it was a very close binary. This was a very, very good night for seeing and the B component was cleanly split though extremely close.

Since it was split cleanly, I had estimated the sep. at >1arcsec but not much more than that. I noticed that the primary was yellowish and the secondary warm-toned or 'ruddy'. I checked my atlases and books and Megastar and noted that besides BU648 there are no other similar doubles with a bright (5th mag) primary and very close companion.

The data I had at hand (Cambridge DS Atlas and Kepple and Sanner's guide, vol.2) (the Haas book doesn't list it) had sep. at 0".7 or 0".6, if I remember correctly. This seemed a bit tighter than what I saw, but this is a short-period binary (very exciting to watch these) and so the sep. could easily have changed significantly in a few years.

Next, I checked the WDS. It is strange that the entry for A-B shows 'sep. now' as 0".39! There is a cool orbit solution shown (two possibilities, actually) that even has a data point for today's date (27 June 2013).

However, also on the same page (the WDS searchable database mentioned elsewhere in this forum, not the WDS itself) shows sep. first as 0".6 (Burnham's discovery meas.) and 'sep. last' as 1".1, which is a lot closer to what I saw. I don't know which to believe - sep. last (meaning last known meas.) or 'sep. now', which is given as 0".39, and which seems /impossible/ for me to have seen so readily, if at all, at only x260, in spite of the very good night of seeing which I had.

Can anyone shed some light on this very interesting double? This is the first one I've observed where what I saw vs. what is the most recent data differed by enough to see at the eyepiece due to orbital motion.


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fred1871
scholastic sledgehammer


Reged: 03/22/09

Loc: Australia
Re: Frustrating Lyra Doubles new [Re: Svezda]
      #5943902 - 06/27/13 10:19 PM

Nice find - quite near to Gamma Lyrae, but BU 648 is not a greek letter star so we can go with the standard double star descriptor, by discoverer, of BU 648.

Looking at the WDS and 6th orbit catalog, the calculated orbit has a period of 61.4 years (though it's quoted as 22430 days!). The other orbit listed is not relevant - it's an astrometric orbit for the secondary star which is an ultra-close short period binary (1016 days) - you'll find the listed separation for that (Ba,Bb) is 0.0".

Returning to the visible pair - the stars, mags 5.34 and 7.96 are changing in separation and angle over time, and at present are in a wider part of the orbit. The last measure is for 2010, PA 255 deg at separation 1.1". The separation is increasing presently, so the ephemeris - 1.2" in PA 248 for 2013.0, looks pretty good.

When you read the WDS, it's important to notice the dates for the measures listed - it gives first (often the discovery) measure, plus the most recent currently on file. Hence the big difference here between 1878 (discovery by Burnham) and 2010 (most recent on file). The gap of 132years does not have the period of 61.4 years as a simple fraction so the measures won't match up - different parts of the orbit are referred to.

Back in 1997 the measure for BU 648 was 0.6" in PA 317, not much different from the discovery numbers - it's obviously widened a lot since then, with decreased PA (317 is NW, 255 is slightly S of W). Once again, the year when you look at these binaries can make quite a difference.

I don't know where the "separation now 0.39"" comes from - that certainly does NOT apply to 2013. Doing a quick check of the orbit, I get a separation of 0.39" listed for the year 2032. And this appears to be the minimum separation in the orbit.

So, what you're seeing is a good match for the listed data in both WDS and the 6th orbit catalog.


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WRAK
Pooh-Bah


Reged: 02/18/12

Loc: Vienna, Austria, Europe
Re: Frustrating Lyra Doubles new [Re: John Fitzgerald]
      #5944352 - 06/28/13 08:04 AM

Quote:

In my light polluted skies, I have difficulty seeing a companion thet is 10th mag or fainter when closer than about 20" to a 6 mag or brighter star. Not enough contrast due to LP; almost like observing near a bright moon. (6" Achro)



John - what is your average naked eye magnitude limit at your location and what is your telescope magnitude limit with these conditions?
Wilfried


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Svezda
scholastic sledgehammer


Reged: 06/01/07

Loc: Texas
Re: Frustrating Lyra Doubles new [Re: fred1871]
      #5945476 - 06/28/13 07:49 PM

Quote:

Nice find - quite near to Gamma Lyrae, but BU 648 is not a greek letter star so we can go with the standard double star descriptor, by discoverer, of BU 648.
Quote:


Fred, of course this isn't a Bayer Greek-letter star. I meant that the new designations for doubles started by someone a couple decades or more ago (I assume due to the difficulty of making machine-readable databases with Greek letters) are unfortunate. They really should have kept the original double star discoverer designations, such as a Greek Beta + 648 for the double currently known as BU648.

To me this is as if the IAU had discarded the traditional constellation names and decided to call them English names like 'The Big Bear' since English is the 'international language'. I guess that I'm just a traditionalist.

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Svezda
scholastic sledgehammer


Reged: 06/01/07

Loc: Texas
Re: Frustrating Lyra Doubles new [Re: Svezda]
      #5945486 - 06/28/13 07:59 PM

Fred, thanks for looking up all that info! I was not using the WDS, rather I was using the WDS searchable database mentioned elsewhere in this DS forum. I am a newbie at looking at the WDS though I've observed doubles for any years, thus my errors thinking that 'sep. now' shown as 0".39 was really for 2013. I still don't know why that data is listed as 'now' when it's for 2032. I knew that what I saw was an arcsecond or so, not much below an arcsecond (I have a good eye for guessing these, and I could see that the PA was something like 260deg since it was almost equal to the drift direction). The value you quoted of 255 is close. The ones that are close to 270 are easy to estimate with a Dob since the drift gives a nice imaginary line at 270deg.

I'm just getting more serious these days due to the fact that they are one of the only classes of celestial objects that I can easily observe from my backyard in the suburbs (NELM at zenith on a really good night with my nighttime myopia-corrected glasses (with crown glass lenses) is about 5. 4.5m is more typical for an average clear night.

I bought an old Darbinian bifilar micrometer and hope to get it calibrated and in use this year. I don't like that it has only one option for an eyepiece, an old surplus 25mm binocular Kellner. This means I will be using a 2x or 4x Barlow with it, but it still may not have enough mag. I don't know if it will even reach focus in my Newtonian with a Barlow. This would be a shame, as the Zambuto mirror yields pinpoint stars like a refractor even at f/4.5 and is great on subarcsecond doubles. My TEC apos won't resolve as close as the 14.5-inch scope, but they should work well with the micrometer.


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Nucleophile
super member


Reged: 05/24/13

Loc: United States
Re: Frustrating Lyra Doubles new [Re: Svezda]
      #5945503 - 06/28/13 08:10 PM

Quote:

Fred, thanks for looking up all that info! I was not using the WDS, rather I was using the WDS searchable database mentioned elsewhere in this DS forum. I am a newbie at looking at the WDS though I've observed doubles for any years, thus my errors thinking that 'sep. now' shown as 0".39 was really for 2013. I still don't know why that data is listed as 'now' when it's for 2032.




If you are using Stelle Doppie (which it sounds like you may be), be careful as some of these "sep. now" values are erroneous----as I learned recently with Zeta HER.


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Svezda
scholastic sledgehammer


Reged: 06/01/07

Loc: Texas
Re: Frustrating Lyra Doubles new [Re: Nucleophile]
      #5945510 - 06/28/13 08:13 PM

ohhhh - thanks for the warning. When I read the Stelle Doppie intro, it sounded like he was even more detail-oriented than I am so I didn't consider that here would be significant errors there...guess I need to learn how to navigate the actual WDS...will read this forum more often and try to learn more about that.

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Nucleophile
super member


Reged: 05/24/13

Loc: United States
Re: Frustrating Lyra Doubles new [Re: Svezda]
      #5945610 - 06/28/13 09:23 PM

Quote:

ohhhh - thanks for the warning. When I read the Stelle Doppie intro, it sounded like he was even more detail-oriented than I am so I didn't consider that here would be significant errors there...guess I need to learn how to navigate the actual WDS...will read this forum more often and try to learn more about that.




Stelle Doppie is amazing for compiling lists--it has changed how I compile lists of targets. But it is good to double check the data.

Here is how I check the online WDS if the name is known:

1. Find the RA value of the binary and open the correct volume
2. do a find (on mac this is apple + f keys) or cntrl f I think on PC
3. type in double name with (initially) no spaces ; eg, STF2452
4. next, insert spaces one at a time in the "find" window between the discoverer code and the numerical designation (eg STF 2452) to redo the search until hit(s) show up in the search window---some take a few spaces like the Ho binaries.

I am sure there are better ways than what I have described--but it works for me.
Also, dont give up if your star has an RA of 12h and it doesnt show up--there are two volumes containing 12h binaries.
(and even then the job isnt done if the binary is rapidly changing--for this consult the 6th orbital catalog which is found on the same home as the WDS.

Hope this helps.


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Svezda
scholastic sledgehammer


Reged: 06/01/07

Loc: Texas
Re: Frustrating Lyra Doubles new [Re: Nucleophile]
      #5954792 - 07/04/13 01:43 PM

Thanks Mark for your detailed and helpful reply. Very useful as I get more serious about double star observing.

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Nucleophile
super member


Reged: 05/24/13

Loc: United States
Re: Frustrating Lyra Doubles new [Re: Svezda]
      #5954859 - 07/04/13 02:36 PM

You are welcome.

Let me add that I have yet to come across a fast moving binary in Stelle Doppie that has correct info in the "sep. now" field---this is clearly a bug in the system. This is odd because for all binaries for which a table a projected separations by year are listed, the data is listed with fidelity from the original data as listed in the 6 th orbit catalog.

I will send the creator of Stelle Doppie a note alerting him to this problem.


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ggalilei
scholastic sledgehammer
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Reged: 09/01/11

Loc: Kentucky
Re: Frustrating Lyra Doubles new [Re: Nucleophile]
      #5966829 - 07/12/13 04:42 AM

Is any of these doubles in Lyra the same as SAO 67612 (big number but easy to locate)? I have tried that one a couple of times with my 18" Dob and could split but it wasn't pretty: I need to learn how to collimate better. I believe the separation is somewhere below 1" and magnitudes are 5.2 and 8.4.
Edit: It seems that SAO 67612 could be B648 (also = HD 176051)? This would be the brighter star next to Sufalat, between beta and gamma, correct?

Edited by ggalilei (07/12/13 09:31 AM)


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7331Peg
Sirius Observer
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Reged: 09/01/08

Loc: North coast of Oregon
Re: Frustrating Lyra Doubles new [Re: ggalilei]
      #5967639 - 07/12/13 03:20 PM

Just checked the Bright Star Catalog (go to the WDS info after you enter the SAO number in the search box at the bottom of the page) and you're correct, SAO 67612 is BU 648. The separation for 2013 is 1.206" (from the WDS Ephemerides table, which is HERE). You'll need to scroll the left column down to 18570+3254 to see the data.

The magnitudes are 5.34 and 7.96, so it's definitely a tough one.


John


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ggalilei
scholastic sledgehammer
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Reged: 09/01/11

Loc: Kentucky
Re: Frustrating Lyra Doubles new [Re: 7331Peg]
      #5967772 - 07/12/13 04:43 PM

Thanks for the info John! I'll try it again: it was a difficult split in the 18" aperture, partly due to my approximate collimation methods. It will make a nice challenge for smaller and better collimated scopes.

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inZet
member


Reged: 02/12/09

Loc: Milan, Italy
Re: Frustrating Lyra Doubles new [Re: Nucleophile]
      #6069936 - 09/08/13 05:06 PM

Quote:

You are welcome.

Let me add that I have yet to come across a fast moving binary in Stelle Doppie that has correct info in the "sep. now" field---this is clearly a bug in the system. This is odd because for all binaries for which a table a projected separations by year are listed, the data is listed with fidelity from the original data as listed in the 6 th orbit catalog.

I will send the creator of Stelle Doppie a note alerting him to this problem.




I thought I corrected this bug. Or not?
Send me an email to inzet -at- yahoo dot com with details.

Gianluca


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