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Double Star SAO Database for Stellarium and GoTo mounts

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#1 aa6ww

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Posted 19 December 2019 - 04:09 AM

I went through the Stelle Doppie double star listings and created a database using all the doubles that were also listed as SAO objects. 

I am always struggling to find a complete, easy to use database which is easy to read, use and understand.

 

Being a recent Celestron Avx GoTo owner, having a database I can use where I can just punch in an SAO object is a big win for me for backyard observing in my light polluted skies. Without GoTo, I'm extremely limited to what I find lately. I see people asking all the time for this, who own GoTo mounts. I've never seen a double star listed focused on SAO objects.

 

Unfortunately, no one I know other then those in this forum, are interested in double star observing because there is no database that is easy for the casual astronomer to look at, and instantly start using without having to call up some other source of information also as a cross reference. 

 

Struve listings are the norm, but converting a Struve object into something usable on Stellarium for example, just doesn't exist for me.

 

So I hope this database helps. I have it separated into three folders.

 

The first folder has everything listed by Constellation, which is the most usable for me.

 

The second  folder is listed by the Star Name. This is handy when the double star experts out here casually use star names instead of catalog designators.

 

The third folder is listed by the Washington Double Star Catalog (WDS) or just by their star Catalog ID. This is where some of the Struve (STF) designators are found alone with other ID's.

 

I hope this helps. Once the skies clear, I'll give this a try. 

 

....Ralph

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Edited by aa6ww, 19 December 2019 - 04:30 PM.

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#2 ButterFly

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Posted 19 December 2019 - 05:19 AM

Excellent list.  Thanks.

 

 

 

Struve listings are the norm, but converting a Struve object into something usable on Stellarium for example, just doesn't exist for me.

 

FYI, for example: ** STF 208A or ** STF 3090A in the search box.  One needs internet for this.

 

Stellarium uses SIMBAD, which is made by astronomers for astronomers.  As such, it makes no sense and the explanation makes even less sense.

 

** is the double star signifier;

STF is the catalogue abbreviation for the ordinary Struve catalog;

the numbers are the numbers: and,

the A is the A star of the system.

 

Try to figure all that out from the SIMBAD Dictionary of Nomenclature, then get the proper catalogue abbreviation from the broken link they provide, which is fortunately on the archives!

 

So, yeah, the list is rather handy.  Thanks again.


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#3 ButterFly

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Posted 19 December 2019 - 05:54 AM

For the convenience of those who still use Burnham's Celestial Handbook

 

Σ     =     STF

OΣ  =     STT

β     =     BU

Δ     =     DUN

 

edit: that does not look right

Sigma    =     STF

O Sigma  =     STT

Beta     =     BU

Delta     =     DUN


Edited by ButterFly, 19 December 2019 - 05:55 AM.


#4 coopman

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Posted 19 December 2019 - 08:04 AM

Thanks for this.  



#5 eklf

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Posted 19 December 2019 - 08:34 AM

Awesome!!

 

That is a great list.

 

A further small request.  If you already have the list from Stelle Doppie..would it be possible to output this list as a skysafari list?  I like to starhop, and often times use skysafari to do so.  To have this list displayed on skysafari as I go from one double to the other would be great.

 

Thanks in advance..



#6 khingdheano

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Posted 19 December 2019 - 11:00 AM

Excellent! Thank you!



#7 aa6ww

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Posted 19 December 2019 - 11:40 AM

 I'm not familiar with Skysafari though I know its well known and preferred by many. Since I use Stellarium and it accepts SAO objects, that is why I came up with this SAO Database. Also, now that I have an Avx mount, direct entry into the  hand controller using SAO objects should be nice also.

Normally, I have a laptop or tablet running beside my mount, with Stellarium opened in one window and one of these Excel databases open in a second window. Having everything available in one window would be nice, as  you are asking about.

 

One thing I like about this list is the star names. Many out here refer to doubles under names only, so searching by name only is a nice added feature. Something simple like the Porrima or Bet Mon is easy to find now.

 

..Ralph

 

 

Awesome!!

 

That is a great list.

 

A further small request.  If you already have the list from Stelle Doppie..would it be possible to output this list as a skysafari list?  I like to starhop, and often times use skysafari to do so.  To have this list displayed on skysafari as I go from one double to the other would be great.

 

Thanks in advance..


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#8 goodricke1

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Posted 19 December 2019 - 03:14 PM

Great work, thanks.



#9 ButterFly

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Posted 19 December 2019 - 08:43 PM

Awesome!!

 

That is a great list.

 

A further small request.  If you already have the list from Stelle Doppie..would it be possible to output this list as a skysafari list?  I like to starhop, and often times use skysafari to do so.  To have this list displayed on skysafari as I go from one double to the other would be great.

 

Thanks in advance..

SkySafari already has a well cross-referenced internal list, so this SAO list will not benefit you very much.  You are better off using the SkySafari search feature to do what this list does (and also further refine if you wish).

 

The AVX uses the NexStar+ handcontroller, which has NO cross-referencing and just the SAO catalogue.  I would manually convert the entries in Burnham's from B1950 to JNow so I can enter the RA/Dec.  This list just makes it a lookup and entry job instead, and it can replace Burnham's in many respects.

 

But say you have the doubles from somewhere else.  For example, PSA Jumbo Chart 33 shows OΣ229, Σ1374, and Σ1338.  In SkySafari, one can just search STT229, STF1374, and STF1338, in airplane mode, and get the results, then do a goto if wifi-ed to the mount.  In Stellarium, one would search **STT229, **STF1374, and **STF1338, but would need internet to connect to SIMBAD.  With the NexStar+, one cannot enter those at all.  You need the SAO number.  Look them up if they exist.


Edited by ButterFly, 19 December 2019 - 08:44 PM.

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#10 ssmith

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Posted 20 December 2019 - 11:12 AM

SAO numbers are all well and good but hand controllers don’t usually have a complete catalog of SAO numbers and not all double stars have SAO designations.

The best solution in my experience is to use Sky Safari on your tablet in conjunction with the SkyFi wireless controller. You eliminate interfacing with the hand controller entirely (which can get a bit wonky in cold temperatures) and you control the scope from your tablet.

Just select any object on the screen and the scope slews to that object. Build your observing lists and they are displayed on the screen. Just touch and go! I’ve never looked back.

img_0178.jpg

#11 aa6ww

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Posted 20 December 2019 - 02:46 PM

The hand controller allows me to enter in coordinates also, so for the 760 plus objects in the database I created, that should more then enough for me.

I prefer using the hand controller and prefer working off the list, so I don't really even need a starchart when I feel like being lazy and using my GoTo mount.

Its never that cold in California.

 

...Ralph


Edited by aa6ww, 20 December 2019 - 02:51 PM.


#12 fred1871

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Posted 20 December 2019 - 07:57 PM

Useful list, Ralph, for those who want to go SAO.... grin.gif

 

I like Steve's suggestion, for those who want to use Sky Safari. Not my choice but it works for a lot of folk.

 

Generating the SAO list made me wonder about the need, rather than the liking, for such an approach. I started with double stars as a teenager long ago, in the days before home computers and go-to systems. I used star-hopping and atlases, and lists of doubles from Norton's Atlas, Webb's Celestial Objects, the Atlas Coeli-II Katalog; and used the Skalnate Pleso Atlas. Other sources were added in later years as they became available. 

 

Moving on some decades, in the mid-1990s I was using star-hopping, with star atlases (including Sky Atlas 2000 and Uranometria) and lists such as the older Saguaro Club lists along with Sky Catalog 2000 volume 2. By then I could computer compile lists of objects by constellation. At home, it was star hopping. At a public observatory where I had a part-time job, push-to with DSS and using RA and Dec from my lists. 

 

These days, I use Celestron and Sky Watcher go-to systems, and I input RA and Dec for go-to. Same lists I started with, though with added objects (computer created and edited).

 

If I were starting out now I suspect I'd be using go-to (bad back, doesn't like star-hopping), using the Sissy Haas book and similar sources. Again, entry of RA and Dec, and without making it part of the scope's data base, which is too limited in size. I've observed around 6,000 doubles, many of them more than once, some multiple times - showpieces, or changing pairs.

 

So, I wonder why finding doubles seems so difficult for some observers. Various ways to skin a cat, as with most things in life. I know that doubles were often unrewarding for the older light-bucket Dobs with mediocre to poor optics, or for SCTs out of collimation or thermally handicapped (or both). But those are fixable issues with the telescopes.

 

I do recognise that the software behind various programs - Stellarium, Sky Safari, etc - makes things more obscure by not using the standard names for doubles, the Struve and similar names. But you can still go by position, RA and Dec.

 

Of course, if those who love obscure star names refer to doubles only by those, you have an extra layer to find your way through - to choose a non-obscure example, STF 1670 is Gamma Virginis is Porrima. Personally, I don't use the proper names alone except for a few commonly known - Sirius, Rigel, etc.  So if I were writing about Delta Corvi I would NOT refer to it as Algorab - the atlas page is in front of me, but is not in front of readers, and memorising 400 or so star names seems to me an unproductive effort. I would likely add that Delta Cor is Sh 145 (a James South/John Herschel double from their collaboration in the early 1820s). That would make it easier to look up for the reader, if they used catalogues instead of, say, Stellarium which doesn't encourage that approach.

 

Okay, I'm getting too lengthy for a single note. My conclusion - find an easy way for getting to doubles, with a suitable telescope - multiple approaches are possible, some of them pretty easy. Ralph and Steve have suggested approaches, I've added others; there may well be more that are the preferred style for some observers.



#13 aa6ww

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Posted 21 December 2019 - 12:02 AM

  .....hence, the title of this thread...

 

 

Useful list, Ralph, for those who want to go SAO.... grin.gif



#14 ssmith

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Posted 21 December 2019 - 09:49 AM

I do recognise that the software behind various programs - Stellarium, Sky Safari, etc - makes things more obscure by not using the standard names for doubles, the Struve and similar names. But you can still go by position, RA and Dec.


Not the case for Sky Safari - you can search it’s database by STF, BU, ARY, etc as well as ADS or WDS identifiers.

My one gripe is that you can’t choose which identifier it uses to display on the screen. If you look at the screen-shot I posted above you can see that most objects are labeled by their Bayer or HD designation.

Edited by ssmith, 21 December 2019 - 09:53 AM.


#15 fred1871

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Posted 21 December 2019 - 06:21 PM

Not the case for Sky Safari - you can search it’s database by STF, BU, ARY, etc as well as ADS or WDS identifiers.

My one gripe is that you can’t choose which identifier it uses to display on the screen. If you look at the screen-shot I posted above you can see that most objects are labeled by their Bayer or HD designation.

That's my point - Sky Safari prefers not to use Struve, Burnham, etc as the first choice designations, instead leaving them to be found in the big bag of names, rather than giving primacy in the way the WDS and typical doubles-centred literature does. I have less problem with Bayer than HD, as it's usually easier/quicker to identify which double is referred to.


Edited by fred1871, 21 December 2019 - 06:22 PM.


#16 ButterFly

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Posted 22 December 2019 - 05:55 PM

The AVX, with good alignment, put doubles in the field of a 3-6 Nagler on a 900mm scope.  The bottleneck for me from lists was converting to JNow for RA/Dec entry because even J2000 misses in most parts of the sky.

 

By far, the best solution would be if Celestron let us import a custom observation list to the handcontroller. 

 

Short of that, one must take steps to work with either limited databases with no cross-referencing or coordinate conversion.  Otherwise, you're switching eyepieces to starhop and that just eats up time and defeats the purpose of goto.

 

Skysafari is great with the AVX.  It pops up everything in Burnham's without issue.  But I'd rather avoid a phone screen if I can.



#17 fred1871

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Posted 23 December 2019 - 01:30 AM

The AVX, with good alignment, put doubles in the field of a 3-6 Nagler on a 900mm scope.  The bottleneck for me from lists was converting to JNow for RA/Dec entry because even J2000 misses in most parts of the sky.

 

By far, the best solution would be if Celestron let us import a custom observation list to the handcontroller. 

 

Short of that, one must take steps to work with either limited databases with no cross-referencing or coordinate conversion.  Otherwise, you're switching eyepieces to starhop and that just eats up time and defeats the purpose of goto.

 

Skysafari is great with the AVX.  It pops up everything in Burnham's without issue.  But I'd rather avoid a phone screen if I can.

I'd say the bottleneck is largely a result of the small field of view of the 3-6mm Nagler, even at 6mm, giving 150x, because of the 50-degree afov. It works out to nearly 20 arcminutes field size. Given the usual approximations of affordable go-to systems like the AVX, it's not too surprising that modest pointing errors can add to the precession changes, even with 20-years ago J2000 positions. For 1950 positions (why?) I'd agree, for them converting the positions to Jnow is better.

 

Looking at precession for a 20 year period, it's mostly plus in RA, and typically 1 minute of RA (more or less) for the 20 years of change. Declination will usually shift a little, can be Northward or Southwards in direction, and change by zero to around 6-7 arcminutes. Not a huge difference. But with the approximations of typical go-to, plus these changes and a 20' field, yes, objects can be left outside the field. Of course, with a larger starting field size, objects will still be in the field using J2000 positions and the near-enough of typical go-to.
 

Why you start with 150x, for what is presumably a modest aperture, is what I don't know. It sounds like the Bruce McEvoy approach of using enough power to see the diffraction disc at first sight. Workable with small scopes, assuming a 1mm exit pupil, so 80x on an 80mm refractor and 100x on a 100mm. But when we get to a 12-inch scope, such as Bruce has, that's around 300x. Seems a bit extreme.

 

Personally I've always preferred to approach doubles "in context" - that is, use a lesser power that gives a field perhaps around 35' to 50' wide, using a wide-field eyepiece. That gives enough power to show what's in the field around the double, and to separate the easier pairs, if we're considering scopes in the 4-inch to 8-inch range, the "common telescopes" of our time.

 

Back when I had acccess to a 7-inch f/9 apo scope, my favourite eyepiece for the first look at a double was a 16mm Nagler II, giving ~100x with a 48' field. The power was enough to show pairs as pairs down to, say, 1.5" separation, It also gave a good field context of the pair. And you could then change eyepieces for higher powers for the tighter pairs.

 

At the same observatory, using a C14, I would start with a moderate power, say a 55mm Plossl or 32mm Wide-Field. That gave a field size on the sky between 30' and 40'. Again, add magnification according to taste for the closer doubles. 

 

Star-hopping with go-to (dratted system didn't find the object) is something I've only had to do on rare occasions when the system didn't synch properly with the initial settings and failed to say it had failed. In that case I would switch off and re-calibrate the go-to; so far, has worked each time.

 

Overall, then, what's necessary for easily finding doubles involves choices. Small fields put a strain on our friendship with semi-accurate go-to systems. In which case, starting with a bigger field size will help greatly and usually solve any finding issues, thereby restoring peace in the camp. So choose a wider-field-on-the-sky eyepiece as a starting point.


Edited by fred1871, 23 December 2019 - 02:06 AM.

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#18 ButterFly

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Posted 25 December 2019 - 05:27 AM


Why you start with 150x, for what is presumably a modest aperture, is what I don't know.

Convenience and efficiency.  The AVX puts it in the field once JNow is used.  One could, of course, use the wrong coordinates, hunt around at low power, then switch eyepieces, but I'd prefer to just have the mount go there and start observing.  Having the javascript convert the coordinates is much faster than hunting around at low power then switching eyepieces.  If one enjoys the hunt, hunt away.



#19 fred1871

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Posted 25 December 2019 - 08:57 PM

Convenience and efficiency.  The AVX puts it in the field once JNow is used.  One could, of course, use the wrong coordinates, hunt around at low power, then switch eyepieces, but I'd prefer to just have the mount go there and start observing.  Having the javascript convert the coordinates is much faster than hunting around at low power then switching eyepieces.  If one enjoys the hunt, hunt away.

Nice to know it can "put it in the field...". However I have the impression you've not understood what I was saying. My essential suggestion is to use a second eyepiece, additional to the Nagler zoom, which gives a much larger field so you start by seeing the double in its celestial context. This works for me with J2000 positions and common Celestron and Skywatcher go-to mounts. Object is in the field every time, no hunting needed.

 

It works with my C9.25 with a 24mm Panoptic, power 98x, field 40'. So I stay with 1.25" eyepieces, and no need for fiddly adapters for 2". It works with my older 140mm refractor, 10mm Pentax XW giving 80x and 50' field. Those are my usual "first view" eyepieces with those scopes. Easy enough to change to another eyepiece for more power.

 

It seems to me that you are keen to avoid field context, keen to see the diffraction disc of the star, and keen to use only one eyepiece. That leaves you with a need to convert J2000 to Jnow positions, to be sure of getting the object in the field first off. If that's your preferred style, so be it. I was pointing to other possibilities. You're free to try any approach you wish. I prefer less work (converting positions) and more possibilities in the observing. Why limit yourself to one eyepiece, even if it is a high quality zoom?
 



#20 aa6ww

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Posted 30 December 2019 - 01:41 AM

I had a chance a Friday night  to use my SAO Double Star database with my Avx mount. Using My SW-120ED I had a chance to locate about 40 double stars in the course of the night. Orion, Cassiopeia, Perseus, Auriga and Cepheus were all all visible constellations.

Selecting common names and random SAO Numbers from the SAO Database, every object I wanted to look for was there in my Starsense Database and the Avx with Starsense centered every object, using my 20mm 100 degs eyepiece as my starting point.

 

So far so good with this new SAO database.

 

...Ralph


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#21 ScottW

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Posted 08 February 2020 - 07:16 PM

Ralph,

 

Thanks a ton!

I too use my handbox and SAO numbers.  

That's enough technology for me.

You did a great job and service, thanks again.

 

Scott




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