My Columbae

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Star
μ Columbae
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Dove
Right ascension 05 h 45 m 59.9 s
declination -32 ° 18 ′ 23.2 ″
Apparent brightness 5.18 likes
Typing
B − V color index −0.28 
U − B color index −1.06 
R − I index −0.27 
Spectral class O9.5 V
Astrometry
Radial velocity (109.0 ± 1.8) km / s
parallax (2.15 ± 0.16)  mas
distance 1,500  ly
450  pc
Visual absolute brightness M vis −2.9 mag
Proper movement 
Rec. Share: (2.98 ± 0.16)  mas / a
Dec. portion: (−22.24 ± 0.20)  mas / a
Physical Properties
Dimensions 12  M ☉
radius 4.5  R ☉
Luminosity

23 300  L ☉

Effective temperature 33 700  K
Rotation time <1.5 days
Age 2.7 million  a
Other names
and catalog entries
Bayer name μ Columbae
Cordoba Survey CD -32 ° 2538
Bright Star Catalog HR 1996 [1]
Henry Draper Catalog HD 38666 [2]
Hipparcos catalog HIP 27204 [3]
SAO catalog SAO 196149 [4]
Tycho catalog TYC 7061-1617-1 [5]Template: Infobox star / maintenance / specification of the TYC catalog
2MASS catalog 2MASS J05455989-3218232 [6]
annotation
  1. ↑ Estimated from apparent brightness and distance.

My Columbae (μ Col / μ Columbae) is a star of the spectral class O9.5 in the constellation Dove, about 1500 light years from Earth . With an apparent magnitude of 5.2 mag, it is still visible to the naked eye. According to its spectral class, My Columbae rotates fairly quickly with a period of rotation of less than 1.5 days. For example, the sun, with a diameter that is almost five times smaller, takes 25.4 days for one full revolution. Due to its strong stellar wind , My Columbae loses 0.1 millionths of the solar mass per year.

Together with AE Aurigae and 53 Arietis , My Columbae belongs to the group of so-called runaway stars . The three stars are moving away from the Orion association at high space velocities . Their speeds and directions of movement suggest that they were around 2.5 million years ago in the vicinity of today's trapezoid in the constellation Orion, were driven out of the Orion association and flew away in different directions. According to one theory, the three stars originally formed a multiple system in Orion with a more massive fourth star, until this fourth component exploded as a supernova due to its large mass and the energy released in the process ejected the other three stars from the Orion association. My Columbae, for example, then moved very quickly from its place of origin in Orion to its current position in the constellation Dove, as seen from Earth. Another theory is that the three runaway stars may have been thrown out of the Orion association by gravitational interaction due to accidentally too close proximity to other massive stars.

However, based on new calculations, Professor Jim Kaler assumes that only AE Aurigae and My Columbae were part of two binary star systems that came too close to each other 2.5 million years ago near today's trapezoidal stars (which did not exist then), so that the two runaway Stars were thrown away and now strive away from each other at 200 km / s, while the other two stars remained behind and formed today's double star Nair Al Saif in Orion.

Due to its large mass (about 12 times that of the Sun), My Columbae will explode as a supernova and later, as a pulsar, move unusually quickly high above the galactic plane.

literature

  • Runaway stars. In: The Brockhaus. Astronomy . 2006, p. 395.

Individual evidence

  1. ↑ a b c d mu. Col. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 3, 2018 .
  2. ↑ a b c Bright Star Catalog
  3. ↑ Pulkovo radial velocities for 35493 HIP stars
  4. ^ Hipparcos, the New Reduction (van Leeuwen, 2007)
  5. ↑ a b c d e f Mu Col. Jim Kaler, accessed November 3, 2018 .
  6. ↑ So the article Runaway Stars in Brockhaus Astronomie (2006), p. 395.