27 Canis Majoris

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27 Canis Majoris A/B
Observation data
Epoch J2000.0
Constellation
(pronunciation)
Canis Major
Right ascension 07h14m15.2s
Declination −26°21′09″
Apparent magnitude (V) +4.42 (+4.9/+5.4)
Absolute magnitude (V) -4.00 (-3.5/-3.0)
Distance 1580 ± 450 ly
(480 ± 140 pc)
Spectral type B3IIIe
Other designations
27 CMa, EW Canis Majoris (component B), HR 2745, HD 56014, BD −26° 4057, HIP 34981, SAO 173264, GC 9608, CCDM J07143-2621

27 Canis Majoris, also called 27 CMa, is a star system in the constellation Canis Major. It is approximately 1580 light years from Earth and has a mean apparent magnitude of +4.42.

The primary component, 27 Canis Majoris A, is a blue-white B-type giant with an apparent magnitude of +4.9. It is also a spectroscopic binary with an orbital period of 0.262 days.

The second component, 27 Canis Majoris B, is separated from the primary by 0.1 arcseconds and has an orbital period of 31 years. Its apparent magnitude is +5.4 and it is classified as a Gamma Cassiopeiae type variable star. Due to its variable nature, the brightness of the system varies from magnitude +4.42 to +4.82.