These are links to the actual star catalogs which were used to generate SkySafari's stellar databases. Again, all of these are highly technical resources.
SKY2000 Master Star Catalogs - NASA Flight Dynamics' Star Catalog Database. A complete and comprehensive catalog of the brightest 300,000 stars in the sky, to magnitude 9; it includes data from Hipparcos and Tycho, below, and is kept well-maintained and up to date by NASA. This is SkySafari and SkyGazer's basic source of stellar data.
The Hipparcos Space Astrometry Mission - European Space Agency's mission site for the landmark Hipparcos astrometry satellite, which provided stellar parallax and proper motion measurements with unprecedented accuracy in the early 1990s - and are still the best available today.
The Hipparcos and Tycho Catalogues - ESA, 1997; hosted at the CDS in Strasbourg. The official results of the Hipparcos mission. The Hipparcos catalog contains the highest-precision measurements on 120,000 or so stars; the Tycho catalog augments this with lower-precision data on just over 1 million stars. SkySafari 4's database augments NASA's SKY2000 catalog with data from Hipparcos and Tycho.
The Tycho-2 Catalog - Erik Høg. An updated version of Tycho, released in 2000, containing improved positions and proper motions for over 2.5 milion stars by combining Tycho data with earlier ground-based observations. Still the definitive standard for stars not already included in Hipparcos.
Catalogs and Surveys Branch - of the Space Telescope Science Institute. Home of the Digitzed Sky Survey and the Guide Star Catalogs.
Guide Star Catalog, version 1.2 - at the Space Telescope Science Institute. The original Guide Star Catalog, containing data on 19 million objects (of which 15 milion are stars), created to support the Hubble Space Telescope. For many years, the largest star catalog in existence.
Guide Star Catalog, version 2.3 - at the Space Telescope Science Institute. The second-generation Guide Star Catalog. Containing data in multiple color passbands, as well as proper motions, and reduced errors, for nearly 1 billion objects; complete to at least magnitude 19 or so.
General Catalog of Variable Stars - Sternberg Astronomical Institute, Moscow, Russia. The definitive source of data on variable stars and suspected variables.
Washington Double Star Catalog - Brian D. Mason, Gary L. Wycoff, and William I. Hartkopf, Astrometry Department, U.S. Naval Observatory, Washington, DC. The world's principal database of astrometric double and multiple star information, for the components of over 100,000 systems.
Sixth Catalog of Orbits of Visual Binary Stars - William I. Hartkopf & Brian D. Mason, U.S. Naval Observatory, Washington, DC. The authoritative compilation of visual binary star orbits, including orbits for just over 2000 currently-known visual binary stars. From the WDS folks.
Neaby Stars Database (NStars) - at Northern Arizona University. The most current, complete and accurate source of scientific data on stars within 25 parsecs; at present this includes approximately 2600 stars.
Research Consortium on Nearby Stars (RECONS) - Todd J. Henry, Professor of Physics and Astronomy, Georgia State University, Atlanta, GA. The mission of RECONS is characterize all stars within 10 parsecs (32.6 light years). Contains a nice data table of the 100 nearest star systems.