Cambridge Double Star Atlas - New Horizons!

[cloudsweeper]

I haven't concentrated much on Doubles, but they are a very interesting, wide and varied class of celestial objects - especially when pollution and poor transparency generally rule out the fuzzies.

To assist in the exploration, I have bought (and just received) the Cambridge Double Star Atlas.  It lists 2,500 binary/multiple gravitationally-bound systems within reach of an amateur telescope.  They are described as "astronomically local", and the finest 330 of them are indicated by a star (what else?).

There is a long and informative introduction, followed by charts then lists of doubles, arranged by constellation.  The lists state the components of each system, their separations (Greek rho) in arcseconds, and other data.

The CDSA shows similar stellar detail to Sky and Telescope's Pocket Sky Atlas (PSA), but more than that in the Cambridge Star Atlas (CSA).  But the latter two volumes both predictably show fewer doubles as such (each indicated by a spot with a bar through) than the CDSA.  The CDSA also gives catalogue designations.

An interesting point is given in the intro on page 14, namely that in poor seeing, doubles benefit from increased mag since the Airy Disc of bright stars can been seen through the turbulence.  Furthermore, at higher mag, the improved contrast helps with spotting faint components otherwise lost in diffraction rings.

I look forward to enjoying more of these treasures over coming sessions.

Here are images from the CDSA, PSA, and CSA for comparison.

Doug.

 

[rwilkey]

Hi Doug, yes, the CDSA is a brilliant piece of kit and a great guide, the maps are so detailed that it makes it easy for any amatuer to search the sky and tease out the little gems. 

[cotterless45]

Plenty multiple stars , just drop down the forum to Science " Observing and imaging double and variable stars " . Some links ,

http://users.compaqnet.be/doublestars/

http://eaglecreekobservatory.org/eco/doubles/

Wish those with light pollution would consider stars , they're fairly immune to light pollution and give super rewards,

Nick.

[John]

I recently acquired the Cambridge Double Star Atlas as well. It's pretty good but I'm not finding that I'm using it all that much. I seem to prefer Interstellarium where the layout gives you an indication of the tightness of the separation on the atlas itself whereas you have to look it up separately in CDSA. 

It's not a big quibble and I expect the CDSA is more comprehensive but it's a little niggle that keeps it on the shelf more than it deserves

[chiltonstar]

I like the charts - the tables at the back less so, as they are sometimes a little confusing, and including only proven gravitationally bound pairs can be an annoyance. But a brilliant book though, and I always marvel at the skills and patience of authors of works like CDSA.

Chris

[F15Rules]

Great acquisition Doug?.

I had the CSA (not the CDSA) and have the PSA. I let the CSA go and kept the PSA as my eyes seemed to prefer the latter outdoors under red light..a very personal thing which might be the opposite with other observers. Certainly the CSA was/is beautifully produced.

I haven't used the PSA much as yet and I've also now got Double Stars for Small Telescopes by Sissy Haas, which lists over 2000 doubles together with useful notes and comments. Sissy used a small (3 or 4" I think) refractor for her observing but the selection includes doubles that need a 5" or 6" aperture (one of the reasons I bought it, as my main scope is a 5" Tak), so I'm really looking forward to testing the Tak on many of these over winter and into 2018.

My main enemy is time at the moment. I feel that for me it would be best to put together a planned observing program, maybe one constellation at a time, so that I am disciplined and focused and can really get to grips with non-standard pairs in the way Nick (Cotterless) clearly can. As I only get short sessions as a rule, I often end up looking at the usual suspects, Albireo, Double Double, Mizar, Delta Cygni, as well as M42, M13, M57 and other "celestial lollipops" etc just because I might only have an hour and can find all these very quickly and instinctively.

I'm hoping that in retirement, I hope in early 2019, I can get more, longer sessions to really put these great star atlas resources to better use!

Thanks for posting your thoughts Doug☺..

Dave

[cloudsweeper]

15 minutes ago, F15Rules said:

Great acquisition Doug?.

I had the CSA (not the CDSA) and have the PSA. I let the CSA go and kept the PSA as my eyes seemed to prefer the latter outdoors under red light..a very personal thing which might be the opposite with other observers. Certainly the CSA was/is beautifully produced.

My main enemy is time at the moment. I feel that for me it would be best to put together a planned observing program, maybe one constellation at a time.

Thanks for posting your thoughts Doug☺..

Dave

Thanks Dave!

Yes, planning a session is a very good idea.  I'm doing just that with the CDSA for Gemini, noting the classifications such as 2+2+2 sextuple, 2+1 triple, 2+2 quadruple, etc., where the 2 represents a binary proper.

I'm keeping all three volumes, since they each have their own merits.  CDSA for emphasis on doubles of course, but with much detail for many objects, and large format.  The CSA has additional charts and tables and summary tables of objects opposite each star chart.  But I reckon the one I favour most for general use is the PSA because it has a little more all-round detail, albeit on smaller charts.

BTW - I'm sure you'll enjoy retirement; it'll soon be here!

Doug.

 

[alan potts]

I do have the double star atlas and the normal one which personally I do not rate at all but like John I prefer Interstellarium, it is just so much better.

Alan

[Paz]

I use the tables at the back of the cdsa to identify nice targets when I know I'll be observing in a particular patch of sky. Then I tag them in sky safari.

[davyludo]

Thanks for posting this Doug. I have PSA but personally I find the print just slightly too small to be able to easily read in the dark without putting on some reading glasses....which I don't need for observing. 

So I have actually been looking at getting CSA for my xmas....however I've recently acquired a mak and have started looking at some doubles (attacked a few in Orion at the weekend and it was actually more enjoyable than previous experience with doubles). 

I'm now trying to work out if CDSA would be a better investment - and whether it would really be more like PSA but larger areas and larger text (looks like CDSA shows more stars that CSA).

I assume it still has DSOs like the "normal" CSA version and can still be used as a regular star atlas? Probably a stupid question!

 

[cloudsweeper]

1 hour ago, davyludo said:

Thanks for posting this Doug. I have PSA but personally I find the print just slightly too small to be able to easily read in the dark without putting on some reading glasses....which I don't need for observing. 

So I have actually been looking at getting CSA for my xmas....however I've recently acquired a mak and have started looking at some doubles (attacked a few in Orion at the weekend and it was actually more enjoyable than previous experience with doubles). 

I'm now trying to work out if CDSA would be a better investment - and whether it would really be more like PSA but larger areas and larger text (looks like CDSA shows more stars that CSA).

I assume it still has DSOs like the "normal" CSA version and can still be used as a regular star atlas? Probably a stupid question!

 

Thanks, Davy!  I would say so (highlighted above) - the charts are a lot bigger, although the text size is not noticeably so.  And Yes, the CDSA does show other objects - there's the usual key above each two-page chart indicating stellar magnitudes, doubles, variables, open and globular clusters, planetary, dark, and diffuse nebulae, and galaxies.

So - the PSA is smaller, and has marginally more detail/objects, but the CDSA is bigger, and still has much detail.  I suppose the one I could actually do without would be the CSA but it has handy tables of all objects right next to each chart, which I like!  The decision is yours!  As for me, I reckon I'll keep 'em all!

Doug.

[melsmore]

I have the PSA, CDSA and SkyAtlas 2000. I use the PSA the most. I see there is now the "Jumbo PSA" too - don't' know what it's like https://www.shopatsky.com/jumbo-pocket-sky-atlas. Does Anyone have it?

[davyludo]

Good to know that CSA and CDSA are different enough that one doesn't become obsolete of you have both. 

Might add them both to my Amazon wish list and see which one Santa brings! Astro roulette, exciting 

[davyludo]

24 minutes ago, melsmore said:

I have the PSA, CDSA and SkyAtlas 2000. I use the PSA the most. I see there is now the "Jumbo PSA" too - don't' know what it's like https://www.shopatsky.com/jumbo-pocket-sky-atlas. Does Anyone have it?

I had noticed the jumbo was available now as well. I'd thought about getting it because I find text in the pocket size one ever so slightly too small for me. But have decided to try CSA or CDSA instead so that I don't have basically 2 of the exact same star atlas.

Would be useful to know what others think about it though. 

[cloudsweeper]

37 minutes ago, melsmore said:

I have the PSA, CDSA and SkyAtlas 2000. I use the PSA the most. I see there is now the "Jumbo PSA" too - don't' know what it's like https://www.shopatsky.com/jumbo-pocket-sky-atlas. Does Anyone have it?

Wish you hadn't reminded me of this - I'm trying to avoid more duplication and expenditure - but it is probably an excellent work!!

Doug.

[davyludo]

From what I have read, the jumbo version is exactly the same as the pocket version in terms of the contents.....but less pocket friendly, more jumboish. 

[Ruud]

Hi Doug, 

+1 for the Cambridge double star atlas. Beautiful charts by Tirion! Definitely my favourite.

I also have a few other double star books. Found them all together on a second hand book market:

• Mullaney, James - Double and Multiple Stars and How to Observe Them
• Argyle, Bob (Ed.) - Observing and Measuring Visual Double Stars
• Haas, Sissy - Double Stars for Small Telescopes
• Webb Society - Deep Sky Observer's Handbook vol.1 Double Stars

Of these, Haas' book is the most interesting. It describes the telescopic appearance of many hundreds of double stars.

[cloudsweeper]

9 minutes ago, Ruud said:

Hi Doug, 

+1 for the Cambridge double star atlas. Beautiful charts by Tirion! Definitely my favourite.

I also have a few other double star books. Found them all together on a second hand book market:

• Mullaney, James - Double and Multiple Stars and How to Observe Them
• Argyle, Bob (Ed.) - Observing and Measuring Visual Double Stars
• Haas, Sissy - Double Stars for Small Telescopes
• Webb Society - Deep Sky Observer's Handbook vol.1 Double Stars

Of these, Haas' book is the most interesting. It describes the telescopic appearance of many hundreds of double stars.

Yes, Ruud - I've heard Sissy Haas's book is very good!  And good to hear you favour the CDSA.

Doug.

[Special K]

On 02/11/2017 at 13:52, John said:

I recently acquired the Cambridge Double Star Atlas as well. It's pretty good but I'm not finding that I'm using it all that much. I seem to prefer Interstellarium where the layout gives you an indication of the tightness of the separation on the atlas itself whereas you have to look it up separately in CDSA. 

I’ve just bought this recently as well @cloudsweeper and it looks great!  I did some shopping around and the other contender was Sissy Hass’ Double Stars for Small Telescopes. Both atlases fared well in a test I conducted of Boötes where I compared them with Interstellarum. Like @John I prefer those charts and CDSA has most of the doubles shown, though there are some differences between the two atlases.  There were differences with Haas as well. However I bought CDSA mainly for the data.  Interstellarum is great but it cannot hold all the data really needed to seriously observe, as I found myself wasting time on things I could not see.  I also like to compose an observing list including the mags, separations, etc and didn’t want to rely on being online for that information.  (I love books!!!!)

I’ve got the second edition and understand that’s an improvement over the first.  Of course it’s a useful atlas for all the other objects in the sky and is at a good scale. Looking back I should have just got this instead of starting with the CSA. But CSA is useful for a ‘zoom out’ view when needed. I had no idea CDSA and the Pocket Sky Atlas are on the same scale and that’s useful to know, thanks!  

EDIT:  I forgot to mention my sudden interest in doubles is borne from a recent acquisition of a 6mm Fujiyama orthoscopic!   In testing this against my other EPs I found a new interest in the information about doubles, hence buying the book!

[F15Rules]

On 07/11/2017 at 18:15, melsmore said:

I have the PSA, CDSA and SkyAtlas 2000. I use the PSA the most. I see there is now the "Jumbo PSA" too - don't' know what it's like https://www.shopatsky.com/jumbo-pocket-sky-atlas. Does Anyone have it?

Yes, I'd be interested to know what are the main differences in the Jumbo version..is the print text the same font size, or is it larger?

I've never seen Interstellarium before, but at between c £60 and £75 it does seem very expensive, so it ought to be very good!

Dave

 

[wookie1965]

Here are a couple of pictures of PAS and the jumbo version. 

[cloudsweeper]

Thanks @wookie1965 - the Jumbo version is on my list!

Doug.