HD 50064 is a blue supergiant located in the constellation of Monoceros, easy to see with small telescopes.

HD 50064
Observation data
Epoch J2000      Equinox J2000
Constellation Monoceros
Right ascension  06h 51m 34.1060s[1]
Declination +00° 17′ 50.438″[1]
Apparent magnitude (V) 8.21[2]
Spectral type B6Ia[3]
U−B color index −0.31[4]
B−V color index 0.76[4]
Variable type LBV?[2]
Proper motion (μ) RA: 0.1[5] mas/yr
Dec.: 0.3[5] mas/yr
Distance>2,900[6] pc
Mass45[2] M
Radius200[2] R
Luminosity1,260,000[2] L
Surface gravity (log g)1.5[2] cgs
Temperature13,500[2] K
Other designations
HD 50064, BD+00°1651, MWC 536, 2MASS J06513410+0017503, GSC 00148-02328
Database references


Although it appears quite close to the open cluster NGC 2301 it is much farther away and is not a member of the cluster. It is at least 2,900 parsecs away, more than twice the distance of NGC 2301[6]

HD 50064 has variously been assigned spectral types of B6, B9, and B1, and is readily seen to have a bright supergiant luminosity class. It also shows Hα emission lines with P Cygni profiles, indicating mass loss through a powerful stellar wind.[6]

HD 50064 shows small-amplitude semi-regular pulsations. One strong period of 37 days has been interpreted as a strange mode oscillation and used to calculate the physical structure of the star. A luminosity of approximately 1,260,000 times that of the Sun -placing it among the brightest stars of the Milky Way-, a radius 200 times that of the Sun, and a mass 45 times larguer than the Sun, are derived. The pulsations and its spectrum are similar to those of Luminous blue variables (LBVs). The moderate mass loss suggests that it is an LBV caught pulsating and creating a circumstellar shell.[2]


  1. ^ a b Hog, E.; Kuzmin, A.; Bastian, U.; Fabricius, C.; Kuimov, K.; Lindegren, L.; Makarov, V. V.; Roeser, S. (1998). "The TYCHO Reference Catalogue". Astronomy and Astrophysics. 335: L65. Bibcode:1998A&A...335L..65H.
  2. ^ a b c d e f g h Aerts, C.; Lefever, K.; Baglin, A.; Degroote, P.; Oreiro, R.; Vučković, M.; Smolders, K.; Acke, B.; Verhoelst, T.; Desmet, M.; Godart, M.; Noels, A.; Dupret, M.-A.; Auvergne, M.; Baudin, F.; Catala, C.; Michel, E.; Samadi, R. (April 2010). "Periodic mass-loss episodes due to an oscillation mode with variable amplitude in the hot supergiant HD 50064". Astronomy and Astrophysics. 513: L11. arXiv:1003.5551. Bibcode:2010A&A...513L..11A. doi:10.1051/0004-6361/201014124.
  3. ^ Kohoutek, L.; Wehmeyer, R. (1997). "Catalogue of stars in the Northern Milky Way having H-alpha in emission". Abhandlungen aus der Hamburger Sternwarte. 11. Bibcode:1997AAHam..11.....K.
  4. ^ a b Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
  5. ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862. ISBN 0333750888.
  6. ^ a b c Halbedel, Elaine M. (1990). "Photometry of HD 50064 - A Be supergiant star with a P Cygni profile at H-alpha". Publications of the Astronomical Society of the Pacific. 102: 99. Bibcode:1990PASP..102...99H. doi:10.1086/132612. ISSN 0004-6280.