Vega, HR 7001
|Right Ascension|| 18 : 36 : 56.2 (h:m:s)
|Declination|| +38 : 47 : 01 (deg:m:s)
|Distance|| 26.3 (ly)
|Visual brightness|| 0.03 (mag)
|Spectral type|| A0 Va
Vega, the brightest star in Lyra and one of the brightest in the Northern Sky, is prominent as one of the stars forming the Summer Triangle. It was, since mid 19th century, taken as a norm for gauging stellar magnitudes in all spectral ranges (thus, for norming brightness and color): Its apparent magnitude was defined as magnitude 0.0 in all spectral ranges (so by definition, all color indices for Vega and stars of same spectral type are 0.00). Refined modern magnitude definitions have moved Vega slightly away from the zero point to mag +0.03. Still, stars of same spectral type A0 have color indexes 0, e.g. B-V=0.00.
A remarkable coincidence made Vega accumulate a number of firsts in the history of astronomical discovery and observation:
Precession of Earth's axis will make Vega the Pole Star of the years around 14000 AD.
IRAS detected IR dust disk in 1983, probably a protoplanetary system, where perhaps planets (or planet-like bodies) are going to form.
Hartmut Frommert [contact]