Star Catalogues

From Stellarium Wiki
Revision as of 23:25, 1 November 2007 by Johannes (Talk | contribs)
Jump to: navigation, search

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 applies for the case of ordinary catalog loading at startup, and is an estimate. (MNG managed to load file 7 with 512 M ram, but only just. YMMV). For mmap loading system memory is not a limit any more, see next section.

File name Star Count Magnitude Range File Size RAM needed Availability 5,013 m < 6.0 138K 256M In default package 21,999 6.0 <= m < 7.5 602K 256M In default package 151,516 7.5 <= m < 9.0 4.1M 256M In default package 434,064 9.0 <= m < 10.5 4.2M 256M In default package 1,725,497 10.5 <= m < 12.0 17M 512M Separate download 7,669,011 12.0 <= m < 13.5 44M 512M Separate download 26,615,233 13.5 <= m < 15.0 153M 512M Separate download 57,826,266 15.0 <= m < 16.5 333M 512M (just!) Separate download 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 I recommend 1GB of RAM, and for 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:

cat_file_name_00       =
cat_file_name_01       =
cat_file_name_02       =
cat_file_name_03       =
cat_file_name_04       =
#you can use mmap loading, if you do not want to load all stars
#immediately into RAM:
cat_file_name_05       =
cat_file_name_06       =
cat_file_name_07       =
cat_file_name_08       =
cat_hip_sp_file_name   =
cat_hip_cids_file_name =

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


Prior to version 0.9.1 the files and were falsely called and 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.

Personal tools
in this wiki
other languages