Etoiles

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Dans Stellarium version 0.9.0, les catalogues d'étoiles sont réparties en 9 fichiers qui contiennent des étoiles de luminosité variables. Ces fichiers peuvent être trouvés dans <répertoire d'installation>/ étoiles / default / . Seuls les quatre plus petits fichiers sont livrés avec Stellarium dans le paquet principal afin de conserver la taille gérable.

Environ 99% de toutes ces étoiles viennent du catalogue NOMADE (Naval Observatory Merged Astrometric Dataset version 1, par USNO). Les autres (les plus lumineuses) de Tycho2 et de Hipparcos. Veuillez lire le fichier README de stellarium pour les conditions dans lesquelles vous pouvez redistribuer ces données provenant du NOMADE

Voici une liste de tous les catalogues. La colonne RAM nécessaire s'applique pour le cas ordinaire de catalogue chargement au démarrage, et est une estimation. (MNG réussi à charger le fichier 7 avec 512 M de mémoire vive, mais tout juste. YMMV). Pour mmap système de chargement de la mémoire n'est pas une limite, pas plus, voir la section suivante.


Nom du fichier Nb d'étoiles Echelle de magnitude Taille fichier RAM nécessaire Disponibilité
stars_0_0v0_1.cat 5,013 m < 6.0 138K 256M par défaut
stars_1_0v0_1.cat 21,999 6.0 <= m < 7.5 602K 256M par défaut
stars_2_0v0_1.cat 151,516 7.5 <= m < 9.0 4.1M 256M par défaut
stars_3_1v0_0.cat 434,064 9.0 <= m < 10.5 4.2M 256M par défaut
stars_4_1v0_0.cat 1,725,497 10.5 <= m < 12.0 17M 512M A télécharger
stars_5_2v0_0.cat 7,669,011 12.0 <= m < 13.5 44M 512M A télécharger
stars_6_2v0_0.cat 26,615,233 13.5 <= m < 15.0 153M 512M A télécharger
stars_7_2v0_0.cat 57,826,266 15.0 <= m < 16.5 333M 512M (just!) A télécharger
stars_8_2v0_0.cat 116,923,084 16.5 <= m < 18.0 674M 1024M? A télécharger



Contents

How to add catalogs

0.10.1

Stellarium 0.10.1 will have an automatic download feature built into the program. To use it, hit [F2] or click on the Configuration button on the left panel. Click on the Tools tab. At the bottom of the dialog, a box called "Star catalog updates" should say "Checking for new star catalogs". After a moment, a button labeled "Get star catalog x of y" should appear. Click on this button to download the first catalog. Once the download completes, the button will appear again if there are more catalogs available. Keep clicking on this button to download all extra catalogs.

Note that you can still manually edit stars.ini, as in previous versions.

0.9.0 - 0.10.0

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 of 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

Memory-mapped 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.

0.10.1

In config.ini, under the [stars] heading, set the key "max_memory" to the maximum amount of memory, in megabytes, to use to load star catalogs directly (the old way). Any catalogs that would push the total memory used over that value will be memory mapped. If unset, the value defaults to 128.

0.9.1 and 0.10.0

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.

Caveat: when using mmap loading, you must use catalog files that match your computers hardware architecture and the compiler used for building stellarium. The ordinary .cat files can be used with little endian computers and gcc: this applies to all PC (i368 and x86_64 architectures) and the newer Intel macs. Nigel Kerr has made a program for converting .cat files into .bcat files, which can be used with big endian computers and gcc (primarily for the older macs with PPC architecture). All others must use my program ConvertCatToNative.C (in the util directory) for converting .cat (or .bcat) files into a native format appropriate for their architecture and compiler.

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.


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