Known Stars UpdateThe number of Known Stars in the database has been increased from approximately 4,500 to over 63,000. This includes every star within 775 light years of Sol, plus a few hundred further out. This doesn't change theoretical game size, as the game will still only generate systems you discover, but it creates a much larger sandbox in which to play.
The basis of the data is an Access database of the Hipparcos Catalogue (HIP), created by the European Space Agency, plus a LOT of parsing and data cleansing by me to sort out misclassifications, duplications, positional errors, etc., before converting everything to something that Aurora can use. A lot of the HIP data (spectral class, naming, etc.) is free text, which can make parsing tricky and is prone to simple typing errors.
In addition, the Hipparcos Catalogue tracks binaries as two separate stars without any link between them and often doesn't use the same nomenclature for linked stars. Fortunately, the Gliese catalogue does have A and B designations and HIP includes the Gliese designation where it exists (although Gliese only has 3800 stars). Even so, figuring out which are binaries has been an significant task. At some point, I am going to do a proximity check on Celestial coordinates and use any close matches as a basis to find some more. This is a lot more difficult further out as many stars are listed by Simbad (see below) as Spectroscopic binaries, so we only know there are two or more stars because the spectrum changes as we are unable to resolve them visually.
The distance also changes the mix of star types. There are a lot of known red dwarves within a hundred light years, but far less further out because we can't detect them.
I've made extensive use of the Simbad database, created by the Strasbourg Astronomical Data Center, which is more up to date, in the data cleansing effort. Simbad is very useful if you know the star designation you need. At first I thought it lacked some key information, until I found out how to calculate distance from parallax information and how to estimate binary separation by using observed arc seconds and distance from Sol
Below is an example page for Simbad. If you know Right Ascension and Declination (the ICRS coordinates), which is the position in the sky, and Parallax, which is how that position changes as Earth orbits the Sun, you can calculate a 3D coordinate relative to Sol. The further away the star, the less accurate the original measurements, but its fine for Aurora. The bottom section is all the different names for this single, relatively obscure, star. The HIP data mixes up names from many different existing catalogues, but provides a new HIP ID as well and Simbad has HIP, so it acts as a Star Catalogue Rosetta stone
I am sure there are still going to be errors in data, although they should not cause bugs. If you do pick up any obvious mistakes - like Antares turning up as a red dwarf - then let me know. In addition to the new information, I've also done a thorough revision of the existing data to correct a few errors.
