Beta Canis Majoris

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**Beta Canis Majoris**
Observation data Epoch J2000
Image:Position Beta Cma.png Location of Β CMa.
Constellation	Canis Major
Right ascension	06^h 22^m 42^s
Declination	-17° 57′ 21.3″
Apparent magnitude (V)	1.98
Characteristics
Spectral type	B1 II-III
B-V color index	-0.23
U-B color index	-0.98
Variable type	Beta Cephei
Astrometry <tr valign=top><td>Radial velocity (R_v)</td><td>34 km/s</td></tr><tr valign=top><td>Proper motion (μ)</td><td> RA: -3.45 mas/yr Dec.: -0.47 mas/yr </td></tr><tr valign=top><td>Parallax (π)</td><td>6.53 ± 0.66 mas</td></tr><tr valign=top><td>Distance</td><td>approx. 500 ly (approx. 150 pc)</td></tr><tr valign=top><td>Absolute magnitude (M_V)</td><td>-3.95</td></tr>
Details
Mass	? M_☉
Radius	? R_☉
Luminosity	19,000 L_☉
Temperature	22,000 K
Metallicity	?
Rotation	36 km/s.
Age	? years
Other designations
Murzim, Murzam, Mirza, 2 Canis Majoris, HR 2294, BD−17°1467, HD 44743, SAO 151428, FK5 243, HIP 30324, GC 8223, CCDM 06227-1757

Beta Canis Majoris (β CMa / β Canis Majoris) is a star in the constellation of Canis Major. It also has the traditional name Murzim or Murzam.

The traditional name is Arabic (مرزم) for 'The Herald', and probably refers to its position, heralding Sirius in the night sky (ie, rising before it). Murzim is a magnitude blue-white giant star. The brightness of Murzim varies between 1.95 and +2.00 in a six-hour period. It is a Beta Cephei variable star.