Flamsteed designation
Flamsteed designations for
stars are similar to
Bayer designations, except that they use numbers instead of Greek letters. Each star is assigned a number and the Latin
genitive of the
constellation it lies in (see
List of constellations for a list of constellations and the genitive forms of their names).
The numbers were originally assigned in order of increasing
right ascension within each
constellation, but due to the effects of
precession they are now slightly out of order in some places. This method of designating stars first appeared in a preliminary version of
John Flamsteed's
Historia coelestis Britannica which was published by
Edmond Halley and
Isaac Newton in
1712 without Flamsteed's approval. The final version of Flamsteed's catalogue published in
1725 after his death omitted any number designations altogether.
The designations gained popularity throughout the eighteenth century, and are now commonly used when no Bayer designation exists; however, where a Bayer designation does exist for a star it is used almost exclusively and the Flamsteed designation is almost never used. Examples of well-known stars which are usually referred to by their Flamsteed numbers include
51 Pegasi (see
Extrasolar planet), and
61 Cygni (see
Parallax).
There are examples of stars bearing Flamsteed designations for constellations in which they do not lie, just as there are for Bayer designations, because of the compromises that had to be made when the modern constellation boundaries were drawn up. It should also be noted that Flamsteed's catalogue covered only the stars visible from
Great Britain, and therefore stars of the far southern constellations have no Flamsteed numbers. (Two exceptions are the globular cluster
47 Tucanae and the nearby star
82 Eridani.)
Some entries in Flamsteed's catalog are errors: for instance, Flamsteed observed
Uranus in
1690 but did not recognized it as a
planet and it entered his catalog as "34 Tauri".
See also
*
star designation*
Flamsteed objects*
List of constellations
