🪐intro to astronomy review

Flamsteed number

Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025

Definition

Flamsteed number is a numerical designation assigned to stars in the order of their right ascension within a constellation. Named after the English astronomer John Flamsteed, these numbers help in identifying and cataloging stars.

AP course connection

Topic 19.2: 19.2 Surveying the Stars

Unit 19

5 Must Know Facts For Your Next Test

  1. Flamsteed numbers were introduced by John Flamsteed in his star catalog published in 1712.
  2. They are used for stars visible to the naked eye and are typically accompanied by the genitive form of the constellation name.
  3. Flamsteed numbers are applicable primarily to constellations in the northern hemisphere.
  4. The system was developed before Bayer designations but is less commonly used today compared to other modern catalogs.
  5. Flamsteed's catalog included over 3,000 stars, many of which still use their original Flamsteed numbers.
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