Beta Crucis
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| Observation data Equinox J2000 |
|
|---|---|
| Constellation | Crux |
| Right ascension | 12h 47m 43.2s |
| Declination | −59° 41' 19" |
| Apparent magnitude (V) | 1.30 |
| Characteristics | |
| Spectral type | B0.5 IV |
| U-B color index | −1.00 |
| B-V color index | −0.15 |
| Variable type | Beta Cephei |
| Astrometry | |
| Radial velocity (Rv) | +15.6 km/s |
| Proper motion (μ) | RA: −48.24 mas/yr Dec.: −12.82 mas/yr |
| Parallax (π) | 9.25 ± 0.61 mas |
| Distance | 350 ± 20 ly (108 ± 7 pc) |
| Absolute magnitude (MV) | −3.92 |
| Details | |
| Mass | 14 M☉ |
| Radius | 8 R☉ |
| Luminosity | 34,000 L☉ |
| Temperature | 28,200 K |
| Metallicity | 80% Sun |
| Rotation | |
| Age | ? years |
| Other designations | |
| Database references | |
| SIMBAD | data |
Mimosa or Becrux (β Cru / β Crucis / Beta Crucis) is the second brightest star in the constellation Crux and one of the brightest stars in the nighttime sky.
Since Beta Crucis is at roughly −60° declination, it is only visible south of the Tropic of Cancer and therefore didn't receive an ancient traditional name. "Mimosa" is a recent name based on its color; "Becrux" is simply a combination of the "Be" in Beta plus Crux. It is known as 十字架三 (the Third Star of the Cross) in Chinese.
Beta Crucis is located approximately 353 light years from Earth's Solar System. It is a spectroscopic binary with components that are too close together to resolve with a telescope. The pair take 5 years to orbit each other, and are separated by about 8 AU. Beta Crucis, being of spectral type B0.5IV, is believed to be the hottest first-magnitude star.
[edit] External links
- MIMOSA. Stars. Retrieved on November 28, 2005.
- Beta Crucis. Alcyone Ephemeris. Retrieved on November 28, 2005.
