First thought upon seeing this add-on - very nice, gotta try it.
Second thought after reading through the thread, trying to load it and quitting after a 3 minute wait - this will simply not stand!
And thus I have converted all 1 million star coordinates, types and luminosities into a .dat file (
M31.dat, 11.4 MB packed, 19 MB unpacked) for everyone to enjoy with quick loading times:
https://docs.google.com/open?id=0BwLaKHFs5JgxV2p5eEdHYnhiOUEUnfortunately, it's not an exact replica - the positions of the stars differ slightly from the original, probably due to the fact that the coords in the .dat files are stored as 4-byte floats in light-years and the distances from the Sun are so huge that this level of precision is not enough. However the errors seem to be on the smaller side (0 - 0.15 ly from the original position), and the loading times are much faster so I think it's a fair trade-off.
I have also created another .dat file (
MW_M31.dat, 43.2 MB packed, 58.6 MB unpacked) - it's a result of the merger between 2.1C Star Database and this one, for anyone who wants to keep the Milky Way stars and enjoy the Andromeda Galaxy at the same time!
https://docs.google.com/open?id=0BwLaKHFs5JgxaEVpMnVQM2hSa3MThe new stars are numbered HIP 10000001 to 11000000 - this maps to some Tycho identifiers, but if you put in "HIP 11000000" in the search box it will find it just fine.
HOW TO USE IT - you probably know it already, but for anyone in need:
0. Unpack the downloaded file.
1. For Andromeda Galaxy alone - backup your original
Celestia/data/stars.dat file, rename
M31.dat to
stars.dat and put it in the
Celestia/data folder.
OR
1'. For Milky Way and Andromeda Galaxy goodness - backup your original
Celestia/data/stars.dat file, rename
MW_M31.dat to
stars.dat and put it in the
Celestia/data folder.
Lastly - two questions to the author:
What does the "CM1" spectral type represent? I couldn't find any info on it, and since Celestia seemed to map it to M1 I did so as well during the conversion.
The other matter is a technicality - there seem to be almost no stars in the core region of the M 31, was it like this in the original distribution too or did the conversion mess it up?