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The letters HD with a number.
Also known as: HD number, HD 209458 style designation
The designation of a star in the Henry Draper catalogue, which classified stars by spectrum rather than position.
Designates a star in the Henry Draper catalogue.
Contexts: History
Covers stars far too faint for a Bayer or Flamsteed name, so an HD number is often the only designation a star has and is the one a research paper uses. It is the designation most stars actually carry.
Contexts: History
Two capital letters followed by a number of up to six digits.