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Old 08-18-2018, 08:15 PM   #1
acrosome
 
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Default Stellar Mapping

Not sure where to put this, but ultimately it is for GURPS, so...

Where can I find a complete dataset for all stellar objects within 10 parsecs of Sol? I need RA, DEC and parallax. I'm trying to make an up-to-date Astrosynthesis file, and I know that this 10pc list is sort of the whole purpose of RECONS, which had an update this year. Yes, I know that there are real-life stellar maps already available for Astroynthesis (from Evil Doctor Ganymede, generally) but they all date to 2012 and a LOT of objects have been added since then, mostly various dwarfs.

I found this RECONS set, but it is limited to certain spectra (looks like L, M, and WD, and a few K) and excludes stars on the RECONS list of 100 nearest stars. I'd like EVERYTHING within 10pc. Basically, I want a list of everything on the RECONS census. The 100 Nearest list goes out to about 22.7ly, and 10pc is 32.6ly, so there have to be more A, F, G, and K stars out there...

I can't find RECONS on the Vizier website. Is there something else that it might be named?

Actually, if I could get a list as accurate as RECONS for everything within 43ly that would be even better. Then I could make eight sectors that are 25ly cubes. But I doubt that such a data set exists.

Last edited by acrosome; 08-20-2018 at 08:55 AM.
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Old 08-18-2018, 09:02 PM   #2
David Johnston2
 
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Default Re: Stellar Mapping

http://stellar-database.com/
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Old 08-18-2018, 09:09 PM   #3
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Default Re: Stellar Mapping

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Originally Posted by David Johnston2 View Post
A very neat resource. But...

It only lists 208 stars for a 32ly search, so it obviously does not include the up-to-date RECONS data, which should list 428 stars. Even removing companion stars to only lists stellar systems it should be 317.

Last edited by acrosome; 08-20-2018 at 08:22 AM.
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Old 08-20-2018, 08:55 AM   #4
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Default Re: Stellar Mapping

I know that there is a Big Brain on this forum somewhere who knows the answer... :)

RECONS publishes their data- or at least the three data that I need (RA DEC parallax). I just can't find it.

Should I just use Hipparcos (or Gliese? which is better?) and add in all those dwarfs from CTIOPI?

EDIT-- Dammit. Hipparcos doesn't list the stellar class... It lists BVI color index, magnitude, and luminosity, but I cannot easily translate that into class. Also, Vizier is truncating all of my searches to 50 stars, and I can't figure out how to get a full list.

I didn't list it above, but I sort of assumed any catalogue would have stellar class, luminosity, and magnitude, all of which I want as well.

Last edited by acrosome; 08-20-2018 at 09:46 AM.
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Old 08-20-2018, 11:21 AM   #5
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Default Re: Stellar Mapping

I found some other archives where you can search stellar datasets (other than Vizier). Here is one from the Gaia project. And here is one from NASA.

So I'll get this eventually, but for now I'm still struggling. For instance, searches are often truncated to 1000 or 2000. But I'm only expecting several hundred star systems, so that should work, yet I keep hitting the max on my searches. The Hipparcos search doesn't let you limit the search by parallax, just RA and DEC, so that's a bother since otherwise it has everything I want. Some datasets do let you limit a search by parallax, but I am clearly not understanding how that works or something because when I try to limit my search to 10 parsecs in the Gaia dataset I get 1722 objects, of which 63 appear to be closer than Proxima Centauri. (And, yes, I am converting milliarcsec to arcsec.)

And I keep seeing parallaxes that are listed as a negative number! How in the hell do you get a negative parallax?!?

Grrr. As I said, I'm not understanding something.
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Old 08-22-2018, 01:58 PM   #6
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Default Re: Stellar Mapping

Quote:
Originally Posted by acrosome View Post
I found some other archives where you can search stellar datasets (other than Vizier). Here is one from the Gaia project. And here is one from NASA.

So I'll get this eventually, but for now I'm still struggling. ... The Hipparcos search doesn't let you limit the search by parallax, just RA and DEC, so that's a bother since otherwise it has everything I want. ...
For future reference (e.g., other searches using the Vizier interface), you can limit the search by parallax, or any other quantity in the database. In the main body of the search page, there's a long list of columns in the database (for Hipparcos, this includes "recno", "HIP", "Comp", "Classes", etc.). Each row has a tickbox for "Show", a radio button for "Sort", the "Name" of the specific database column, and then a text box ("Constraint"), where you can enter a constraint for your search. Whether or not the data in a particular column shows up in the results depends on whether the "Show" box has been ticked.

So if you want only stars between 5 and 6 parsecs, you could enter "5..6" in the "Dist" row (20th row, I think). To get all stars with distances <= 10 pc, you'd enter "<= 10" in the box. At the top of the list of columns, there's a link "Constraints (?)" which will give you a pop-up window explaining the formatting of how to specify constraints.
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Old 08-20-2018, 11:21 AM   #7
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Default Re: Stellar Mapping

Have you written to RECONS to ask them? Todd Henry ( toddhenry28@gmail.com ) was the lead author on the most recent paper.

A negative parallax could be the result of high proper motion or noisy data with large error bars.
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Old 08-22-2018, 05:24 AM   #8
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Default Re: Stellar Mapping

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Originally Posted by thrash View Post
A negative parallax could be the result of high proper motion or noisy data with large error bars.
You can get wacky parallaxes from telescopic binaries, too.
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Old 08-21-2018, 01:13 AM   #9
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Originally Posted by acrosome View Post
Should I just use Hipparcos (or Gliese? which is better?) and add in all those dwarfs from CTIOPI?
If you are adding objects manually, start with the Extended Hipparcos dataset XHIP.

Quote:
Also, Vizier is truncating all of my searches to 50 stars, and I can't figure out how to get a full list.
There is a sidebar on the left with an "preferences" box in it that ought to let you do useful things like set the number of results returned, sort the returns, specify format etc. You can also get it to calculate some values for you, but sadly not spectral type.

Quote:
I didn't list it above, but I sort of assumed any catalogue would have stellar class, luminosity, and magnitude, all of which I want as well.
Special-purpose astronomical catalogues can be startlingly single-minded. That's what makes XHIP so lovely.
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Old 08-21-2018, 02:27 PM   #10
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Default Re: Stellar Mapping

Have you tried this catalog search? It does list the spectral type for stars in hipparcos:

https://heasarc.gsfc.nasa.gov/db-per...n=More+Options
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