Flamsteed designation

The Flamsteed designations are used in astronomy parallel to the Bayer designations for the systematic naming of stars. They were introduced by the British astronomer John Flamsteed.

The designation consists of the Flamsteed number followed by the genitive of the Latin name of the constellation in which the star is, for example, 13 or 23 Ursae Lyrae Maiori. Also common is the use of the abbreviation of the constellation name with three letters, such as 13 Lyr, 23 UMa. Flamsteed numbered the naked- eye stars ascending order of right ascension; due to precession is this order, however, now in places breached.

This type of designation first appeared in Flamsteed's Historia coelestis Britannica, published in 1712 by Edmond Halley and Isaac Newton, but without the consent of Flamsteed. After Flamsteed's death appeared in 1725 an expanded edition of Halley more. The Flamsteed numbers gained in popularity in the 18th century and are also used these days where there is no Bayer designation for a star exists. Since Flamsteed his astronomical observations undertook only from the UK, his catalog contains only the visible stars there, but not of the southern sky.

As with Bayer designations there are a number of stars whose Flamsteed designations would assign them other than normal today constellations due to the reclassification of the official constellation boundaries by the IAU. They were therefore no longer used.