Omicron2 Canis Majoris
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h 03m 01.47134s |
| Declination | −23° 49′ 59.8583″ |
| Apparent magnitude (V) | 3.043 |
| Characteristics | |
| Spectral type | B3 Ia |
| U−B color index | −0.778 |
| B−V color index | −0.107 |
| Variable type | α Cyg |
| Astrometry | |
| Radial velocity (Rv) | 53.88±4.04 km/s |
| Proper motion (μ) | RA: −1.335 mas/yr Dec.: +3.803 mas/yr |
| Parallax (π) | 0.8715±0.3319 mas |
| Distance | 3,590 ly (1,100 pc) |
| Absolute magnitude (MV) | −7.3 |
| Details | |
| Mass | 21.4±2.2 M☉ |
| Radius | 65 R☉ |
| Luminosity | 220,000 L☉ |
| Surface gravity (log g) | 2.05 cgs |
| Temperature | 15,500 K |
| Rotational velocity (v sin i) | 58 km/s |
| Age | 7.4±1.0 Myr |
| Other designations | |
| 24 Canis Majoris, CD−23°4797, FK5 270, HD 53138, HIP 33977, HR 2653, SAO 172839 | |
| Database references | |
| SIMBAD | data |
Omicron2 Canis Majoris (ο2 CMa, ο2 Canis Majoris) is a star in the constellation Canis Major. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. It has an apparent visual magnitude of 3.043, making it one of the brighter members of the constellation. Based upon a distance modulus of 10.2, it is about 3,600 light-years from Earth.