Beta Canis Majoris
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 06h 22m 41.98535s |
| Declination | −17° 57′ 21.3073″ |
| Apparent magnitude (V) | 1.985 (1.97 - 2.01) |
| Characteristics | |
| Spectral type | B1 II-III |
| U−B color index | −0.99 |
| B−V color index | −0.235 |
| Variable type | β Cep |
| Astrometry | |
| Radial velocity (Rv) | +33.7 km/s |
| Proper motion (μ) | RA: −3.23 mas/yr Dec.: −0.78 mas/yr |
| Parallax (π) | 6.62±0.22 mas |
| Distance | 490 ± 20 ly (151 ± 5 pc) |
| Absolute magnitude (MV) | −4.1 |
| Details | |
| Mass | 12 or 12.6 M☉ |
| Radius | 7.4 or 8.2 R☉ |
| Luminosity | 25,700+3,800 −3,300 L☉ |
| Surface gravity (log g) | 3.78±0.08 cgs |
| Temperature | 24,700±300 K |
| Metallicity [Fe/H] | 0.04 ± 0.10 dex |
| Rotation | 13.6±1.2 days |
| Rotational velocity (v sin i) | 31 ± 5 km/s |
| Age | 12.2 or 13.8 Myr |
| Other designations | |
| Mirzam, Murzim, Mirza, 2 Canis Majoris, HR 2294, BD−17°1467, HD 44743, SAO 151428, FK5 243, HIP 30324, GC 8223, CCDM 06227-1757 | |
| Database references | |
| SIMBAD | data |
Beta Canis Majoris (β Canis Majoris, abbreviated Beta CMa, β CMa), also named Mirzam /ˈmɜːrzəm/, is a star in the southern constellation of Canis Major, the "Great Dog", located at a distance of about 500 light-years (150 parsecs) from the Sun. In the modern constellation it lies at the position of the dog's front leg.