Henry Draper Catalogue (HD)

The Henry Draper Catalogue (HD) is a catalogue of the spectral types and positions of 225,300 stars, down to about magnitude 8, compiled by Annie Jump Cannon and her coworkers at Harvard College Observatory between 1918 and 1924 and named in honor of Henry Draper, whose widow donated the money needed to finance it. HD numbers are widely used today, especially for stars that have no Bayer designation or Flamsteed number. Stars numbered 1 to 225300 are from the original catalogue and are numbered in order of right ascension for 1900.0. Stars in the range 225301 to 359083 are from the Henry Draper Extension (HDE), published in 1925-1936 and 1949. The notation HDE is used only for stars in this extension, but even these are usually denoted HD as the numbering ensures there can be no ambiguity.