USNO A2.0 Catalogue

The USNO A2.0 Stellar Catalog is a catalogue of 526,280,881 stars covering the entire sky from -90 to +90 degrees in declination, down to magnitude 19+. More information can be found here.

The AstroPlanner version of this catalogue is 8.8GB in size, and contains the RA/Dec and red Magnitude for each star. To keep the size of this catalogue to a reasonable level and to make it available on a single Flash Drive, other information has been omitted. The included information is unchanged from the original.

Since AstroPlanner is currently limited to catalogue files of size less than 2GB, the catalogue has been broken into 24 zones of 7.5° of declination (as in the original distribution from USNO). Each file is treated as a separate catalogue internally, but AstroPlanner treats the catalogues together as a whole in many cases. This also means you only need install the zones you need (e.g. only those zones visible from your latitude).


  1. The catalogue is supplied on a Flash Drive, in compressed form. It is not usable directly from the Flash Drive, and requires 8.8GB of hard disk space for (a complete) installation.
  2. In theory, the catalogue (or parts thereof) could be burned onto a DVD-ROM and used directly from there, but access would be extremely slow.
  3. The catalogue is in a format only understandable by AstroPlanner, and cannot be used by other applications that might be able to use the original USNO A2.0 catalogue (on 11 CD-ROMS).

Screen shots

Info for USNO A2.0 catalogue

Showing coverage of one zone (-30° to -22.5° declination)

A 0.5° field of view around M11, showing magnitudes down to +19