Mu Columbae
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Columba |
| Right ascension | 05h 45m 59.9s |
| Declination | -32° 18′ 23″ |
| Apparent magnitude (V) | 5.15 |
| Characteristics | |
| Spectral type | O9.5 V |
| U−B color index | -1.06 |
| B−V color index | -0.28 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | +109.2 km/s |
| Proper motion (μ) | RA: 3.01 mas/yr Dec.: -22.62 mas/yr |
| Parallax (π) | 2.52 ± 0.55 mas |
| Distance | 1300 ly (400 pc) |
| Absolute magnitude (MV) | -2.84 |
| Details | |
| Mass | 12-15 M☉ |
| Radius | 4.5 R☉ |
| Luminosity | 23,300 L☉ |
| Temperature | 33,700 K |
| Metallicity | ? |
| Rotation | 1.5 days (~153 km/s.) |
| Age | 2.7 × 106 years |
| Other designations | |
Mu Columbae (μ Col, μ Columbae) is a star in the constellation of Columba. It is one of the few O-class stars that are visible to the unaided eye. The star is known to lie approximately 1,300 light years from the Solar System (with an error margin of a few hundred light years).
This is a relatively fast rotating star that completes a full revolution approximately every 1.5 days. (Compare this to our Sun, which at only 22% of this star's diameter rotates only once every 25.4 days.) This rate of rotation is fairly typical for stars of this class.
Based on measurements of proper motion and radial velocity, astronomers know that this star and AE Aurigae are moving away from each other at a relative velocity of over 200 km/s. Their common point of origin intersects with Iota Orionis in the Trapezium cluster, some two and half million years in the past. The most likely scenario that could have created these runaway stars is a collision between two binary star systems, with the stars being ejected along different trajectories radial to the point of intersection.
Etymology
In Chinese astronomy, Mu Columbae is called 屎, Pinyin: Shǐ, meaning Excrement, because this star is marking itself and stand alone in Excrement asterism, Three Stars mansion (see : Chinese constellation).[1] 屎 (Shǐ) westernized into She by R.H. Allen, with the meaning is "the Secretions" [2]
This star, along with ζ CMa, λ CMa, γ Col, δ Col, θ Col, κ Col, λ Col and ξ Col, were Al Ḳurūd (ألقرد - al-qird), the Apes.[3]
References
- A. Blaauw & W.W. Morgan, 1954, "The Space Motions of AE Aurigae and mu Columbae with Respect to the Orion Nebula", Astrophysical Journal, v.119, p. 625.
- R. Hoogerwerf, J.H.J. de Bruijne, P.T. de Zeeuw, 2000, "The origin of runaway stars", Astrophysical Journal, v.544, issue 2, pp. L133-L136.
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 15 日
- ↑ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Columbae
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
External links
- Mu Columbae by Professor Jim Kaler.
