Star Catalogues

In Stellarium version 0.9.0, star catalogues are split into 9 files, which contain stars of varying brightness. These files can be found in the <installation directory>/stars/default/. Only the smaller four of these files come with Stellarium in the main package to keep the size manageable.

About 99% of all these stars come from the NOMAD catalog (Naval Observatory Merged Astrometric Dataset version 1, by USNO). The rest (brighter ones) from Tycho2 and Hipparcos. Please see the stellarium README file for the conditions, under which you may redistribute data files originating from NOMAD.

Here is a list of all available catalogues. The RAM needed column is an estimate. (MNG managed to load file 7 with 512 M ram, but only just. YMMV).

File name	Star Count	Magnitude Range	File Size	RAM needed	Availability
stars_0_0v0_1.cat	5,013	m < 6.0	138K	256M	In default package
stars_1_0v0_1.cat	21,999	6.0 <= m < 7.5	602K	256M	In default package
stars_2_0v0_1.cat	151,516	7.5 <= m < 9.0	4.1M	256M	In default package
stars_3_1v0_0.cat	434,064	9.0 <= m < 10.5	4.2M	256M	In default package
stars_4_1v0_0.cat	1,725,497	10.5 <= m < 12.0	17M	512M	Separate download
stars_5_2v0_0.cat	7,669,011	12.0 <= m < 13.5	44M	512M	Separate download
stars_6_2v0_0.cat	26,615,233	13.5 <= m < 15.0	153M	512M	Separate download
stars_7_2v0_0.cat	57,826,266	15.0 <= m < 16.5	333M	512M (just!)	Separate download
stars_8_2v0_0.cat	116,923,084	16.5 <= m < 18.0	674M	1024M?	Separate download

To try out the large catalogue files download them from here, and put then in the stars/default sub-directory of the Installation Data Directory.

NOTE: when downloading from this page, do not right-click and save as - left click. These are not direct download links - they are links to the list of download mirrors. Left click on them, and wait for your download to start.

For using stars_7_2v0_0.cat i recommend 1GB or RAM, and for stars_8_2v0_0.cat at lease 1.5GB. In version 0.9.0 the catalogs are just loaded into RAM, and if you do not have enough of it, swapping will start. Add up the star catalog sizes, compare with your amount of RAM, and your common sense will tell you how many files you can load. Yours, Johannes

mmap loading

Since version 0.9.1 you can instruct your computer to load all the stars into main memory not at startup, but to load groups of stars when they are displayed for the first time. This is done using the operating systems mmap function, hence the name "mmap loading". Using this technique you can use all of the star catalogs even if you have very little RAM. Also the initial startup time is greatly decreased. The drawback is that your computer loads the stars during normal program operation, when they are used for the first time. Therefore the scrolling and zooming will not be so smooth as when you load all catalogs at startup in advance.

For each catalog file that you want to use, you can decide if you want to load it at startup or using mmap by prefixing the catalog name with "mmap:" in stars.ini:

[stars]
cat_file_name_00       = stars_0_0v0_1.cat
cat_file_name_01       = stars_1_0v0_1.cat
cat_file_name_02       = stars_2_0v0_1.cat
cat_file_name_03       = stars_3_1v0_0.cat
cat_file_name_04       = stars_4_1v0_0.cat
#you can use mmap loading, if you do not want to load all stars
#immediately into RAM:
cat_file_name_05       = mmap:stars_5_2v0_0.cat
cat_file_name_06       = mmap:stars_6_2v0_0.cat
cat_file_name_07       = mmap:stars_7_2v0_0.cat
cat_file_name_08       = mmap:stars_8_2v0_0.cat
cat_hip_sp_file_name   = stars_hip_sp_0v0_0.cat
cat_hip_cids_file_name = stars_hip_cids_0v0_0.cat

In this example mmap loading is configured for stars_5,...,stars_8 only.

Errata

Prior to version 0.9.1 the files stars_3_1v0_0.cat and stars_5_2v0_0.cat were falsely called stars_3_0v0_0.cat and stars_5_1v0_0.cat. Now this misnaming is fixed. The contents of the files is unchanged, just the names have been fixed in order to reflect the contents, which is stars of type 1 and of type 2, respectively. All you have to do is make sure your file stars.ini lists the names of your star catalog files, no matter whether you use the new names or the old ones.