A revised version of Celestia's default stars.dat, containing 114357 stars, is available at https://www.classe.cornell.edu/~seb/celestia/files/simbad-hipparcos_v114.zip  (about 1.9 MB, expands to  2.2 MB).

The star positions were obtained from the Simbad astronomical database, which uses Gaia DR2 positions for most of its stars. Simbad is available at http://simbad.u-strasbg.fr/simbad/. For details about Gaia, see http://sci.esa.int/gaia/