Epsilon Canis Majoris

Epsilon Canis Majoris, officially known as Adhara, is a binary star system and the second brightest object in the constellation of Canis Major. Its name is a Bayer designation that is Latinised from ε Canis Majoris, and shortened as Epsilon CMa or ε CMa. Adhara is the 22nd brightest star in the night sky with an apparent magnitude of 1.50. About 4.7 million years ago, it was the brightest star in the night sky, with an apparent magnitude of −3.99.^[1] Based upon parallax measurements got during the Hipparcos mission, it is about 430 light years away from the Sun.^[2]

The two stars are named ε Canis Majoris A, officially named Adhara — the traditional name of the star system,^[3][4] and ε Canis Majoris B.

1. ↑ Tomkin, Jocelyn (April 1998). "Once and Future Celestial Kings" (PDF). Sky and Telescope. 95 (4): 59–63. Bibcode:1998S&T....95d..59T.^{[permanent dead link]}
2. ↑ Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M.; Grewing, M.; Van Leeuwen, F.; Van Der Marel, H.; Mignard, F.; Murray, C. A.; Le Poole, R. S.; Schrijver, H.; Turon, C.; Arenou, F.; Froeschlé, M.; Petersen, C. S.; et al. (1997). "The HIPPARCOS Catalogue". Astronomy and Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P.
3. ↑ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
4. ↑ "Naming Stars (including "List of IAU-approved Star Names as of January 1st, 2021")". IAU.org. Retrieved 28 February 2021.