 a bayer designation is a stellar designation in which a specific star is identified by a greek letter, followed by the genitive form of its parent constellation's latin name. the original list of bayer designations contained 1,564 stars. most of the brighter stars were assigned their first systematic names by the german astronomer johann bayer in 1603, in his star atlas uranometria. bayer assigned a lower-case greek letter, such as alpha (Î±), beta (Î²), gamma (Î³), etc., to each star he catalogued, combined with the latin name of the starâs parent constellation in genitive (possessive) form. (see 88 modern constellations for the genitive forms.) for example, aldebaran is designated Î± tauri (pronounced alpha tauri), which means "alpha of the constellation taurus".the letters of the greek alphabet were used in antiquity as numerals, however in a different way. a single constellation may contain fifty or more stars, but the greek alphabet has only twenty-four letters. when these ran out, bayer began using latin letters: upper case a, followed by lower case b through z (omitting j and v), for a total of another 24 letters. bayer never went beyond z, but later astronomers added more designations using both upper and lower case latin letters, the upper case letters following the lower case ones in general. examples include s carinae (s of the constellation carina), d centauri (d of the constellation centaurus), g scorpii (g of the constellation scorpius), and n velorum (n of the constellation vela). the last upper-case letter used in this way was q. ==is alpha always the brightest star?== for the most part, bayer assigned greek and latin letters to stars in rough order of apparent brightness, from brightest to dimmest, within a particular constellation. since in a majority of constellations the brightest star is designated alpha (Î±), many people wrongly assume that bayer meant to put the stars exclusively in order of their brightness, but in his day there was no way to measure stellar brightness precisely. traditionally, the stars were assigned to one of six magnitude classes, and bayer's catalog lists all the first-magnitude stars, followed by all the second-magnitude stars, and so on. within each magn
Astronomical_catalogues Bayer_objects