Uploaded my own star data files

IceAgeTom

Hello all, have been playing around with AstroSyn for a while now and only now decided to join this forum. I found about AstroSyn when I looking for 3-D star mapping info, first discovered Winchell Chung's Project Rho site, which led me to this fine program. Then I learned about the HabCat dataset from Jill Tarter and Margaret Turnbull and the HYG dataset from David Nash, and I had an idea. Like others, I wanted to map the stars in these files using AstroSyn, but the Astrosyn files I've found were just raw data dumps and not what I wanted. So I set about to make my own maps, but unlike others I wanted to create my own sort-of database of the stars, calculating lots of data values and including many catalog numbers for cross-referencing. I also wanted to create a basis for my own SF universe, a little creative experiment of mine, so I also added calculations for various habitability values like habitable zone distance, the orbit period at that distance, tidal force and such (thanks to Stephen L. Gillett's book "World-Building: A writer's guide to constructing star systems and life-supporting planets"; I got the formulas from that nifty book) as well as grouping stars into "Tiers" my own design. I made a spreadsheet which automatically created a Notes field for AstroSyn that contained all of the stellar data, both given and calculated, so in addition to mapping the stars you have access to that data from within AstroSyn. Also, I wanted multiple star systems to be properly formatted for AstroSyb, as well as convering standard galactic coordinates to AstroSyn's format (they're not too different: AstroSyn's X is Xg (galactic X), AstroSyn's

I've uploaded the first public-ready result of this project, space 60ly.zip. It contains two AstroSyn .csv files, one up to 20 light years from Sol that contains almost every known star, minus brown dwarfs and the possible odd red dwarf or two; the other file goes from 20 to 60 light years and has an absolute magnitude cutoff of 9.50. Eventually I'll make a file for the rest of the stars, which are red dwarfs plus some white dwarfs, but right now they aren't that imporant to, plus they make the maps much bigger. I've also included the OpenOffice.org v3.2.1 .ods spreadsheet files used to create the AstroSyn files (OpenOffice is free, so it's what I use), they function as a database and provide the formuals in case you want to make your own files without doing the work.

These are not just data dumps, each star was manually researched using various websites like The Internet Stellar Database, SolStation's star list, ARICNS, RECONS, Atlas Of The Universe, and James Kaler's star page at the Univ. of Illinois, along with the Stellarium software. I didn't strictly adhere to reality either, for instance I standardized spectral types, absolute magnitudes and masses for main sequence class "V" stars, and incorporated a built-in bolometric correction of my own for non-giant stars of type G8 and lower. I was pleasantly surprised to see that my values closely matched "reality" in most cases, spectral types only varied by one or two subdivisions (e.g. a K0 became a G9 or K1). The masses are probably off by more, but I wanted a smooth progression using magnitude "bins" down the spectral types; the "floor" is abs. magnitude 19.5 and .10 solar masses, the very last M9 type. For fictional use they are quite sufficient, and far less messy than reality is.

I am now working on the stars from 60 to 100 light years, got up to 78 light years already, the rest will follow, but it's a LOT of stars.

Tom

Ed_NBOS

Very cool, Tom!

IceAgeTom

Thank you, Ed! It's a personal project of mine, but I think it might be useful to others. If anything, I've already done the work of the coordinate conversion.

I've uploaded the 60-78 light year section, and am now working on the part from 78-90 ly's.

Tom

IceAgeTom

An update, I've uploaded the next installment, Space3 78-90ly, covering 78-90 light years from Sol. Also included is an updated .sector map file containing all three parts, 0 to 90 light years. Next up is doing the 90-100 ly section!

Tom

IceAgeTom

I've uploaded the next installment, Space4 90-100ly, covering 90 to 100 light years from Sol. 586 records in that mere 10ly span, and doesn't include the fainter red dwarfs, not that there's a lot of them at that distance in the HYG database. I've again included an updated .sector map file which has all of the stars in the installments in one map, color-coded and complete with galactic direction markers.

Next up are all of the red and white dwarfs fainter than absolute magnitude 9.5 that I've left out so far, and there are a lot of them in the HYG database, at least 1500. This will take a while, for I have less time right now to devote to this project, but will be working on it.

gilbone

Sweet. Are you a gamer? Writer? Astronomer?

IceAgeTom

gilbone wrote:

Sweet. Are you a gamer? Writer? Astronomer?

Thank you!

Well, I am not a writer, but am into space and astronomy (have a large telescope) and have a strong interest in hard science fiction and "reality"-based SF universes. Stewart Cowley's Terran Trade Authority books had a huge impact on me, that was the kind of SF I was really into, far more than Star Trek actually. I got into world-building with a BASIC program that appeared in a 1983 issue of Creative Computing (ah, those were the days) that was a simple program to generate science-based planets around stars. Over the years I've had ideas for my own SF universe, it soon became sort of a thought experiment in making one, and I wanted something very heavily reality-based (with some creative license taken) Then I discovered (a little late) AstroSynthesis 2, and everything crystalized into this project. One thing to note, the "Tier" value that is listed for the stars is actually my own creation as a part of my fictional universe, it's a grouping of the stars according to desirability. Tier 1 and 2 stars (both the ones in the HabCat database as well as many of my "PlusCat" additions to it) have Earth-like habitable planets, Tier 1 being the most desirable (spectral types F5V to G7V) and Tier 2 being less so (spectral G8V to K5V, with a lowest mass of .66 Solar, the lowest value that still generates habitable worlds in StarGen, which is how I set the lower-limit for K5V). Tier 3 and 4 stars, being the numerous lower-mass K-type dwarfs and red dwarfs, only have Earth-like worlds if they're included in the HabCat database. It all ties into the larger fictional aspects of my universe, but it can be used by anyone (or changed to suit whatever purpose).

Oh, I still have the four TTA books, the artwork alone is reason enough to keep them. It's also amusing to look back now and see that most of the stars that Cowley used are completely unsuitable for hosting habitable worlds, for the most part they're class-A dwarfs or orange giants (which are usually class-A dwarfs that are dying). This is typical when using stars that have proper names or Bayer letters (especially Alpha, Beta and Gamma). I know they have the "name" value but are not usuable for fictional purposes. Oh yeah, and Proxima Centauri? It's a very low-mass red dwarf flare star that could plausibly host one wierd-type habitable world, but the rest of the planets in any system it might have would be ice balls.

IceAgeTom

An update on what I'm doing: While preparing to the remainder of the red and white dwarfs, I've decided to revise and update the earlier installments first, and when done will upload a consolidated .csv file. This project has been done in phases over the course of more than a year, and I've continually revised how I did some things, so the earlier sections aren't up to the standards of the later ones. For one, I started out with doing only the stars in the HabCat database, at first I thought that those would be enough. They weren't (way too many lower-K and red dwarfs in the HabCat), and so I then started on the non-HabCat stars in the HYG database using the formula template from the HabCat spreadsheet (ironically I looked up the Hipparcos numbers in the HabCat to identify them in the HYG, so I could have started out with the HYG from the beginning...ah, well). That actually resulted in a rather embarassing error with the galactic coordinates that I made, fortunately it had a minor effect on the results. It happened because the HabCat had Right Ascension and Declination in standard Hours-Minutes-Seconds (HMS) and Degrees-Minutes-Seconds (DMS) format, which I converted to decimal degrees format. The HYG database however has the RA and DEC in decimal hours and decimal degrees, which I then separaratly converted to HMS and DMS format, both for ease of changing when necessary and so I could use them in my existing HabCat-based spreadshdeet template. The error came from the fact that the HabCat's Declination has the the seconds value out to one decimal place, but my converted DMS format had the seconds value out to TWO decimal places, and I never updated the formula that converted it to decimal degrees format to account for that change (it was really simple, just needed to change a RIGHT(xx;4) to RIGHT(xx,5)). Since the RA and DEC were used to calculate the galactic coordinates, those weren't as accurate as they should have been. I've now fixed this error, by making the HabCAT stars' DEC seconds value out to two decimal places (just added a "0" to the end) to match that of my HYG stars' value, and using the proper formula.

Another area of revision is that I'm using the SIMBAD site for these earlier sections. I originally never used SIMBAD to do the HabCat stars, and only used it for the HYG stars with the later sections, and so missed a lot of secondary catalog numbers and other potenially helpful data. I've already deleted several stars that were actually non-existent (artifacts caused by scattered light from a brighter star) or no-motion background stars misidentified as a component of a double star. Some other stars are being revised to being double, or doubles going to being single if the data is rather inconclusive (I've already been doing that, but I've some more examples). Some display names for certain stars are being changed, masses for some old stars others are being revised to my current standards, some extra stars are being tagged with detected planets that I didn't know about before, and other various update and clean-ups are being done. The earlier files are still usuable and I'll leave them up for the time being, but this will be a final updated version--until I add the remaining red dwarfs--as well as being a single file for ease of use.

IceAgeTom

Progress so far......Finished the update through 60 light years, was rather extensive, just about every star had some change/edit applied to it. Some display names have been changed, and very many secondary (the Alt Name field) catalog numbers have been added through the use of SIMBAD. Multiple-star catalog numbers (the Struves, Burnhams, etc.) are now given, where possible, to the individual components of multiple stars in the Alt Name field as well, and a general secondary identifier instead is given to the "base" or parent star. I've also deleted some stars, errors in the existing data that I didn't catch earlier. Some were errors in the Hipparcos catalog (like non-existent stars that are artifacts caused by scattered light from a nearby bright star), others were dubious double stars based on faulty observations but are stil listed as double in some databases. I've even added a few fainter red dwarfs, might add a few more for this update.

When I finish this update through 100 light years, it will replace the four existing files, it's that extensive. The bulk of the fainter red dwarfs not included will be uploaded as separate files so they won't clutter up the main file (they don't really matter for my fictional purposes); I will also give them a special tag so that they can be found and treated separatey (liked being "turned off") within AstroSynthesis