A list of Struves

[AndyWB]

So Turn Left at Orion has lots of references to Struves - my first night out included splitting a couple - and the observing guide I've got mentions a lot, so I was wondering - does anyone know of a list of all of them?

(I quite enjoyed splitting Xi-Scorpii and nearby Struve 1999 last night, and it set me wondering what other ones are around)

[wxsatuser]

The Cambridge Double Star Atlas has Appendix C which lists all doubles with companions at or above mag 7.5.

They are listed with RA/DEC, MAG, separation and constellation.

In the list look for entries marked with Σ

Example...........Castor would be Σ 1110

You may see these listed elsewhere as STF 1110

STF for FGW Struve

Also there are listed Otto Struve doubles, these are marked O Σ

Example........Almaak would be O Σ 38

There are also first and second appendix doubles marked as follows.

1st appendix ..........Σ I

2nd appendix..........Σ II

Plus Pulkova appendix marked as O ΣΣ

[pbyrne]

Here's a couple of good sites for doubles, one is in French, but they are loaded with info.

www.astrosurf.com/agerard/observ.html

www.carbonar.es/s33/33.html

http://www.eaglecree...rg/eco/doubles/

[rwilkey]

I use the Cambridge Atlas of Double Stars, more than enough in here to get you well into doubles.

[AndyWB]

Thanks! Funny, I didn't even consider that there would be books with lists in them; the Cambridge atlas looks pretty good. I'd also not realised that there were the different types of struves.

[Qualia]

Ay, The Cambridge Double Star Atlas is a nice double-guide and atlas in general.

You might also finding the following useful:

Beautiful Doubles

Fun With Doubles

More Doubles

You might also want to try your own, manual hand at measuring them and working out their position angle. I wrote little topic of the game Measuring Doubles

[wxsatuser]

Ay, The Cambridge Double Star Atlas is a nice double-guide and atlas in general.

You might also finding the following useful:

Beautiful Doubles

Fun With Doubles

More Doubles

You might also want to try your own, manual hand at measuring them and working out their position angle. I wrote little topic of the game Measuring Doubles

Nice Links., thank you.

Yes the atlas is also a great general atlas that lists all the usual stuff that would keep most of us busy for a while.

[cotterless45]

Very nice readable book is from Sky and Telescope : "Double stars for small telescopes" by Sissy Haas. Not only includes the uthor's observations , but historical ones,

Nick.

[AndyWB]

You might also want to try your own, manual hand at measuring them and working out their position angle. I wrote little topic of the game Measuring Doubles

Thanks, that is interesting - and I have wondered about whether there was a way to measure angular distances.

Unfortunately, the eyepiece would cost as much as my scope(!) so it might have to wait a bit - still, a thought for the future...

[Qualia]

Ay, I agree the eyepiece is expensive and in today's market of cheapish cams and the such, I'm not convinced it is worth its asking price.

There is a great way of working out Position Angle which costs no more than a 360 protractor, a bit of card and double sided sticking tape, a couple of €s at tops. Follow these instructions (ignoring the stuff about the metric eyepiece) and then turn straight to page 3 about measuring the angle.

I think actively working with our gear and what we see by keeping a log book or sketching or working with doubles in this fashion is a great way of improving our skills as astronomers, for although it seems a waste of time in todays world of Hubble images and the such, doing these kind of simple things force us to participate and think about what we are viewing rather than just casually observing.

If you need any hand, just drop me a line.

[foundaplanet]

Here is another link for your mounting collection.

Ed; you already have it..

[AndyWB]

Hmm. I'm not sure I get how to measure angles like that without an eyepiece with some sort of guide? I mean, how do you 'point' it to the double? Also, I'm guessing that this would really need an EQ mount?

I'm with you on the log book thing - I'm not much of a sketcher, but keeping track of what you've found, how to find it, and so on seems good. It's also a way of checking you've seen what you think you've seen - e.g. I'm pretty sure I saw Vesta in M35, but I'd like to check M35 again to make sure it isn't there now, you know?

[chiltonstar]

The Cambridge atlas is good - the ring bound maps are also very helpful. Be aware though that star to star distances change with time, and even the position angle (PA), so some values in there may be out of date.

I occasionally estimate PA by turning off the drive, and then using the drift direction (W) to estimate the angle relative to that. Approximate, but useful.

Chris

[AndyWB]

Actually, thinking about this some more, my question should maybe have been "Is there a double star equivalent of the Messier/Caldwell/Herschel 400 lists?" One of the links above went to a list called the 'Coldfield 200' - is that any good?

[Qualia]

Actually, thinking about this some more, my question should maybe have been "Is there a double star equivalent of the Messier/Caldwell/Herschel 400 lists?" One of the links above went to a list called the 'Coldfield 200' - is that any good?

I'm aware that the beginning of the Cambridge Atlas give a nice list of around 133 showpiece gems, you can also enjoy working through something like the Coldfield 200 which won't let you down, but personally, I'd go with Camvridge's Mullaney and Tirion's insight who advise that "it's much more fun and exploratory to look at objects shown as doubles on the Atlas maps to see if they can be resolved, the number of companions visible and what colours if any are present before checking lists like those in the showpiece roster..."

[AndyWB]

"it's much more fun and exploratory to look at objects shown as doubles on the Atlas maps to see if they can be resolved, the number of companions visible and what colours if any are present before checking lists like those in the showpiece roster..."

Aye, there's something to be said for that - I stumbled across Delta and Zeta Lyrae while looking for the Ring Nebula the first time, and felt lucky for it. I guess it's just I'd like to have something to give a little 'shape' to what I'm looking for - and also 'cos doubles aren't always that obvious, either as they're too close or deviously far apart!

[Qualia]

That's a fair point, Andy and I find myself nodding in agreement with what you say. Such is the way of astronomy (just wait when you ask about EPs, you'll get more answers than replies ). I think you'll have a nice time with the Coldfield list, for example, but in the end, if doubles were to be a part of your session, I think the Cambridge Double Star Atlas would be a really nice treat. If your birthday is coming up soon, this might be a nice addition.

Last night I was out on the roof top and thought I'd take a gander around Collinder 399. There's a few doubles here you might want to check out: Σ 2504, 2871, 2521, 2585 and a small, but quite a pretty cluster like NGC 6823.

By pure coincidence, I came in after the session last night to swot up a little before going to bed and found that someone had had the same idea: Hanging out with the Coathanger. This might make a nice part of your session this week.