Editing Flamsteed designation (section)

==Description==
{{See also|IAU designated constellations}}
[[File:Atlas Coelestis-14.jpg|thumb|left|[[Orion (constellation)|Orion]] and [[Taurus (constellation)|Taurus]] from Atlas Coelestis]]Flamsteed designations for [[star]]s are similar to [[Bayer designation]]s, except that they use numbers instead of Greek and Roman letters. Each star is assigned a number and the Latin [[genitive]] of the [[constellation]] it lies in (see [[88 modern constellations]] for a list of constellations and the genitive forms of their names). Flamsteed designations were assigned to 2554 stars. 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]]'' published by [[Edmond Halley]] and [[Isaac Newton]] in 1712 without Flamsteed's approval.<ref>{{cite web
 | url = http://www.iau.org/public_press/themes/naming/ | title = Naming Astronomical Objects
 | publisher = [[International Astronomical Union]] (IAU)
 | access-date = 2015-09-10 }}</ref><ref>{{cite web
 | url = http://spider.seds.org/spider/Misc/naming.html | title = Naming Stars
 | publisher = [[Students for the Exploration and Development of Space]] (SEDS)
 | access-date = 2009-01-30 }}</ref> The final version of Flamsteed's catalogue published in 1725<ref>{{cite book |first=John |last=Flamsteed |title=Historia Coelestis Britannica |url=https://archive.org/details/bub_gb_8q9FAAAAcAAJ|publisher=H. Meere |date=1725}}</ref> after his death omitted the numerical designations altogether. The numbers now in use were assigned by the French astronomer, [[Jérôme Lalande|Joseph Jérôme de Lalande]] and appeared in his 1783 almanac, ''Éphémérides des mouvemens célestes'' which contained a revised edition of Flamsteed's catalogue.<ref>{{cite book |first=Joseph Jérôme |last=de Lalande |title= Éphémérides des mouvemens celestas |url=https://books.google.com/books?id=pZAAAAAAMAAJ&pg=PR133|publisher=Hérissant |date=1783 |page=cxxxiii}}</ref> Lalande noted in his Introduction that he got the idea from the unofficial 1712 edition.<ref>{{cite book |first=Joseph Jérôme |last=de Lalande |title= Éphémérides des mouvemens celestas |url=https://books.google.com/books?id=pZAAAAAAMAAJ&pg=PR133|publisher=Hérissant |date=1783 |page=xxv}}</ref>

Flamsteed designations gained popularity throughout the eighteenth century, and are now commonly used when no Bayer designation exists.  Where a Bayer designation with a Greek letter does exist for a star, it is usually used in preference to the Flamsteed designation. (Flamsteed numbers are generally preferred to Bayer designations with ''Roman'' letters.) Examples of well-known stars that are usually referred to by their Flamsteed numbers include [[51 Pegasi]], and [[61 Cygni]]. Flamsteed designations are often used instead of the Bayer designation if the latter contains an extra attached number; for example, "[[55 Cancri]]" is more common than "Rho<sup>1</sup> Cancri".

There are examples of stars, such as [[10 Ursae Majoris]] in [[Lynx (constellation)|Lynx]], 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.

Flamsteed's catalogue covered only the stars visible from [[Great Britain]], and therefore stars of the far southern constellations have no Flamsteed numbers. Some stars, such as the nearby star 82 Eridani, were named in a major southern-hemisphere catalog called ''Uranometria Argentina'', by [[Benjamin Gould]]; these are [[Gould designation|Gould numbers]], rather than Flamsteed numbers, and should be differentiated with a G, as in [[82 G. Eridani]]. Except for a handful of cases, Gould numbers are not in common use.  Similarly, Flamsteed-like designations assigned by other astronomers (for example, [[Hevelius]]) are no longer in general use. (A well-known exception is the [[globular cluster]] [[47 Tucanae]] from [[Johann Elert Bode|Bode]]'s catalog.)

84 stars entered in Flamsteed's catalog are errors and proved not to exist in the sky:<ref name=wagman/> All of them except 11 Vulpeculae were plotted on his star charts.
* Flamsteed observed [[Uranus]] in 1690 but did not recognize it as a [[planet]] and entered it into his catalog as a star called "34 Tauri".
* [[11 Vulpeculae]] was a nova, now known as [[CK Vulpeculae]].
* Many of them were caused by arithmetic errors made by Flamsteed.