Henry Draper Catalogue

The Henry Draper Catalogue (HDC) is a comprehensive star catalog that categorizes stars based on their brightness and spectral characteristics. Compiled in the late 19th and early 20th centuries under the direction of Dr. Edward Charles Pickering, it includes data on over 300,000 stars. The catalog is named after Henry Draper, a pioneer in astrophotography. It serves as a crucial resource for astronomers, helping them understand the composition, temperature, and distances of stars. The HDC was one of the first systematic classifications of stars and laid the groundwork for modern astronomy research.