Pi2 Columbae

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Pi2 Columbae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Columba
Right ascension 06h 07m 52.85895s[1]
Declination −42° 09′ 14.5489″[1]
Apparent magnitude (V) 5.50[2]
Spectral type A0 V + A[3]
B−V color index +0.00[2]
Radial velocity (Rv) +31.0±3.7[4] km/s
Proper motion (μ) RA: −11.00[1] mas/yr
Dec.: −16.40[1] mas/yr
Parallax (π) 13.43 ± 0.23[1] mas
Distance 243 ± 4 ly
(74 ± 1 pc)
Absolute magnitude (MV) +1.17[5]
Mass 2.64 M
Luminosity 31[7] L
Surface gravity (log g) 4.38±0.14 cgs
Temperature 11,223±382 K
Rotational velocity (v sin i) 274 km/s
Age 98 Myr
Other designations
π2 Col, CD−42° 2351, HD 42303, HIP 29064, HR 2181, SAO 217730[8]
Database references

Pi2 Columbae is a binary star[9] system in the southern constellation of Columba. It is a dim but visible to the naked eye with an apparent visual magnitude of 5.50.[2] Based upon an annual parallax shift of 13.43 mas as seen from Earth,[1] this star is located about 243 light years from the Sun. The pair have an angular separation of 0.1[3] arc seconds with the primary being an A-type main-sequence star of spectral class A0 V,[3] while the secondary component is a similar A-type star.[9] The system is a source of X-ray emission with a luminosity of 184.3×1020 W, which is considered unusual since A-type stars are not expected to display magnetic activity.[3]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa, 27: 11, Bibcode:1968MNSSA..27...11C. 
  3. ^ a b c d Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars", Astronomy and Astrophysics, 475 (2): 677−684, Bibcode:2007A&A...475..677S, doi:10.1051/0004-6361:20077429. 
  4. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048Freely accessible, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61. 
  5. ^ Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694−706, arXiv:1606.09028Freely accessible, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035. 
  6. ^ David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154Freely accessible, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146. 
  7. ^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037Freely accessible, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x. 
  8. ^ "pi02 Col". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-28. 
  9. ^ a b Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878Freely accessible, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.