Nearby stars are included in the distribution package of Celestia from version 1.4.0pre5 onwards - so you SHOULD NOT install this add-on if you have Celestia 1.4.0pre5 or a later version. Using this add-on with v1.4.0 will cause a horrible mess.
Two versions of NearStars are available.
nearstars1.zip, which includes the three missing stars, and defines brown dwarfs as the lowest available class, M9V.
nearstars2.zip, which omits the three additional stars (because they are already available in
stars.dat), and assigns the correct spectral classes to brown dwarfs.
If you are in any doubt about which release of Celestia 1.3.1 you have,
out the following test. Open Celestia. Hit [Return] and type "Alula
(careful of the spelling!) and then hit [Return] again. Now press
takes you to the star Alula Australis, you have the newer version of
and therefore need to download
If Celestia goes nowhere, you
have the older version of stars.dat, and need
nearstars1.zip(6.5KB, 13 June 2003, updated 22 Sep.'03)
nearstars2.zip(6KB, 13 June 2003, updated 28 Aug.'04)
Unzip one of these files into your Celestia root directory. It will create a directory called "NearbyStars" in your extras directory, containing two files:
nearstars.stc, containing definitions for nearby non-Hipparcos stars
stellarcompanions.ssc, containing orbital definitions for companion stars
Between them, these files make a fairly complete definition of stellar systems in the neighbourhood of Sol: out to ~25ly. Orbits are derived mainly from the Sixth Catalogue of Orbits of Visual Binary Stars, and have been converted to Celestia coordinates so that their appearance is correct when seen from Sol. However, observations usually leave some doubt as to whether a particular node on the plane of the sky is ascending or descending - this means that the 3D orientation of the orbit may be incorrect in its tilt towards or away from Sol. For some orbits, only the period of revolution is known - in these cases, a plausible semimajor axis has been worked out from the estimated mass of the stars involved. When no orbital data are available, companion stars have been defined in their current positions in space.
Because of the current limitations of Celestia, stars in orbit around other stars have to be defined as emissive "planets", so their appearance is rather unsatisfactory, but their orbital behaviour is interesting.
Grant Hutchison June 2003
Archive: nearstars1.zip Length Date Time Name -------- ---- ---- ---- 0 06-12-03 19:47 extras/NearbyStars/ 1430 06-13-03 13:16 extras/NearbyStars/nearbystars-readme.txt 6967 06-12-03 19:33 extras/NearbyStars/nearstars.stc 13514 06-10-03 00:49 extras/NearbyStars/stellarcompanions.ssc 0 06-13-03 13:15 extras/ -------- ------- 21911 5 files Archive: nearstars2.zip Length Date Time Name -------- ---- ---- ---- 1443 03-05-04 20:21 NearbyStars/nearbystars-readme.txt 6832 06-11-04 20:08 NearbyStars/nearstars.stc 13873 09-22-03 17:04 NearbyStars/stellarcompanions.ssc 0 02-16-04 17:56 NearbyStars/ -------- ------- 22148 4 files
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