Henry Draper Catalogue

The Henry Draper Catalogue is an astronomy catalogue with positional and spectroscopic data about more than 225,000 stars.

The catalogue was first published between 1918 and 1924 by Annie Jump Cannon and her co-workers at Harvard College Observatory under the supervision of Edward C. Pickering, and was named in honour of Henry Draper, whose widow donated the money required to finance it.

Stars contained in the catalogue are of medium magnitude, down to about 9^m (about 50 times dimmer than the faintest stars visible with the naked eye). This makes them average-looking in amateur telescopes, and bright stars for professional instruments. The catalogue covers the whole sky and is notable as the first large-scale attempt to catalogue spectral types of stars.

HD numbers are widely used today for stars which have no Bayer or Flamsteed designation. Stars numbered 1-225300 are from the original catalogue and are numbered in order of right ascension for 1900.0 epoch. Stars in the range 225301-359083 are from the 1949 extension of the catalogue. The notation HDE is used only for stars in this extension, but even these are usually denoted HD as the numbering ensures that there can be no ambiguity.