Mirzam, a blue giant star in Canis Major
Mirzam is a blue giant star in the constellation Canis Major. At 492 light years away, it is the 48th brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 1.98.
Mirzam (HIP 30324)
Mirzam is a blue giant star in the constellation Canis Major. At 492 light years away, it is the 48th brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 1.98. Mirzam is the primary component of a multiple-star system and an intrinsic variable star that varies between magntitudes 1.88 and 1.91 over a period of 6 hours. The iron abundance of Mirzam is -0.41 (38.9% of the Sun). It is moving through the Galaxy at a speed of 33.8 km/s relative to the Sun. Its projected Galactic orbit carries it between 21,400 and 24,600 light years from the center of the Galaxy. It came closest to the Sun 4.4 million years ago when it had brightened to magnitude -3.78 from a distance of 35 light years.
Sky position: RA 6h 22.7m, Dec -17° 57.6'
Common designations: Mirzam, Beta Canis Majoris, 2 Canis Majoris, HIP 30324, HD 44743
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Brightest stars in Canis Major:
(list all)
1
| -1.44
) Sirius
| Rank | Mag. | Star |
| 2 | 1.50 | Adhara |
| 3 | 1.83 | Wezen |
4
| 1.98
) Mirzam
| Rank | Mag. | Star |
| 5 | 2.45 | Aludra |
| 6 | 3.02 | Furud |
| 7 | 3.02 | Omicron-2 Canis Majoris |
| 8 | 3.49 | Sigma Canis Majoris |
| 9 | 3.50 | Kappa Canis Majoris |
| 10 | 3.89 | Omicron-1 Canis Majoris |
| 11 | 3.95 | Nu-2 Canis Majoris |
| 12 | 4.01 | Omega Canis Majoris |
| 13 | 4.08 | Theta Canis Majoris |
| 14 | 4.11 | Muliphein |
| 15 | 4.34 | Xi-1 Canis Majoris |
| 16 | 4.36 | Iota Canis Majoris |
| 17 | 4.37 | Tau Canis Majoris |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Mirzam
(compared to the Sun)
E
ccentricity: 6.9% vs. 16.0%Angle φ : -156.5°vs. 26.0°
Semi-major axis : 7,061 pc vs. 8,686 pc
Semi-minor axis: 7,044 pc vs. 8,574 pc
Focus-to-center
: 488 pcvs. 1,388 pcSemilatus rectum : 7,027 pc vs. 8,464 pc
Perigalacticon: 6,573 pc vs. 7,297 pc
Apogalacticon
: 7,548 pcvs. 10,074 pcSome Tabulated XHIP Data for Mirzam
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 95.67494722° ±0.15 mas | -3.23 ±0.19 mas/yr. |
| Declination: | -17.95591681° ±0.15 mas | -0.78 ±0.20 mas/yr. |
| Galactic Longitude: | 226.05984606° | -0.62 mas/yr. |
| Galactic Latitude: | -14.26803976° | -3.26 mas/yr. |
Parallax: 6.62 ± 0.22 mas
Spectrography
Spectral Type: B1III 2009A&A...501..297Z.
Radial Velocity: 33.70 ±0.50 km/s [A rating] 2006AstL...32..759G.
Iron Abundance [Fe/H]:
-0.41 dex
1992ApJ...387..673G.
Photometry
| band | magnitude | Abs. Mag. |
| U | 0.77 | -5.12 |
| B | 1.74 | -4.15 |
| V | 1.98 | -3.91 |
| R | ||
| I | 2.17 | -3.72 |
| J | ||
| H | ||
| K |
B-V: -0.24 V-I: -0.19
Derivations
Heliocentric distance: 150.86 pc (3.3% margin of error)
Galactocentric distance: 7,502 pc
Transverse velocity: 2.4 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -101.5 pc | -105.3 pc | -37.2 pc |
| Velocity (U, V, W) | -22.6 km/s | -22.8 km/s | -10.6 km/s |