BD+40° 4210

From Wikipedia, the free encyclopedia
Jump to: navigation, search
BD+40° 4210

Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cygnus
Right ascension 20h 31m 4.6s
Declination +40° 30′ 57.05″
Apparent magnitude (V) 10.45
Spectral type B1III:e[1]
Apparent magnitude (K) 4.466
B−V color index 1.68
Variable type candidate LBV[1]
Proper motion (μ) RA: -3.8 mas/yr
Dec.: -2.8 mas/yr
Distance 4,700[1] ly
(1,450 pc)
Absolute magnitude (MV) -7.66
Mass 54 M
Luminosity (bolometric) 630,000[2] L
Other designations
BD+40° 4210, IRAS 20292+4020, PPM 60064, AG+40 2061, 2MASS J20310464+4030568, TYC 3157-679-1
Database references

BD+40° 4210 is a blue supergiant star located in the constellation Cygnus


This star, heavily reddened and extinguished by the interstellar dust of the Milky Way and little studied until now, has turned out to be one of the most luminous stars of the Cygnus OB2 association, with an absolute magnitude of -7.66[1] and a bolometric luminosity more than 600,000 times that of our Sun.[2]

Its location on the Hertzsprung-Russell diagram put it in the same place as quiescent luminous blue variable stars, suggesting it may be a star of that kind; other peculiarities of its spectrum suggest the same too.[1]

BD+40° 4210 is located close in projection (at 4.8 parsecs) to another luminous blue variable candidate, G79.29+0.46; however, unlike the latter which is surrounded by an extensive ring-shaped nebulosity, no nebula has been found around this star.[1]


  1. ^ a b c d e f Comerón, F.; Pasquali, A. (2012). "New members of the massive stellar population in Cygnus". Astronomy & Astrophysics 110: 2715. Bibcode:2012A&A...543A.101C. doi:10.1051/0004-6361/201219022. 
  2. ^ a b In and around the rich association Cygnus OB2