Alpha Columbae

Alpha Columbae
Location of α Columbae (circled)
Observation data
Epoch J2000      Equinox ICRS
Constellation Columba
Right ascension 05h 39m 38.94103s
Declination −34° 04′ 26.7950″
Apparent magnitude (V) 2.645
Characteristics
Spectral type B9Ve or B7 IV
U−B color index −0.44
B−V color index −0.125
R−I color index −0.09
Variable type γ Cas?
Astrometry
Radial velocity (Rv)+35.0 km/s
Proper motion (μ) RA: −1.58 mas/yr
Dec.: −24.82 mas/yr
Parallax (π)12.48±0.36 mas
Distance261 ± 8 ly
(80 ± 2 pc)
Absolute magnitude (MV)−1.87
Details
Mass4.5 M☉
Radius7±0.14 R☉
Luminosity3,311 L☉
Surface gravity (log g)3.5±0.04 cgs
Temperature12,200±122 K
Rotational velocity (v sin i)176 km/s
Age93 Myr
Other designations
Phact, α Col, NSV 2549, CD−34 2375, CPD−34 703, FK5 215, GC 7078, HD 37795, HIP 26634, HR 1956, SAO 196059, PPM 281732, CCDM  J05396−3404 A
Database references
SIMBADdata

Alpha Columbae is a third magnitude star in the southern constellation of Columba. It has the proper name Phact (/ˈfækt/); Alpha Columbae is the Bayer designation, which is Latinized from α Columbae. This star has an apparent visual magnitude of 2.6, making it the brightest member of Columba. Based upon parallax measurements made during the Hipparcos mission, Alpha Columbae is located at a distance of around 261 light-years (80 parsecs).

Nomenclature

α Columbae, Latinized to Alpha Columbae, is the star's Bayer designation. It is abbreviated Alpha Col or α Col.

The traditional name of Phact (also rendered Phad, Phaet, Phakt) derives from the Arabic فاختة fākhitah 'ring dove'. It was originally applied to the constellation Cygnus and later transferred to this star. The etymology of its name hadāri (unknown meaning) has also been suggested. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Phact for this star.

In Chinese, 丈人 (Zhàng Rén), meaning Grandfather, refers to an asterism consisting of α Columbae and ε Columbae. Consequently, α Columbae itself is known as 丈人一 (Zhàng Rén yī, English: the First Star of Grandfather). From this Chinese name, the name Chang Jin has appeared.

Properties

This is believed to be a solitary star, although it has a faint optical companion at an angular separation of 13.5 arcseconds, making it a double star. The stellar classification of Alpha Columbae is B9Ve, matching a B-type main-sequence star. The spectrum shows it to be a Be star surrounded by a hot gaseous disk, which is generating emission lines because of hydrogen recombination. Like most if not all such stars, it is rotating rapidly with a projected rotational velocity of 176 km s−1. The azimuthal equatorial velocity may be 457 km s−1. It is a suspected Gamma Cassiopeiae type (GCAS) variable star, with its apparent magnitude varying from 2.62m to 2.66m.

References

  1. 1 2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015 XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 7 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  3. 1 2 3 4 Cousins, A. W. J. (1972). "UBV Photometry of Some Very Bright Stars". Monthly Notes of the Astronomical Society of Southern Africa. 31: 69. Bibcode:1972MNSSA..31...69C.
  4. 1 2 3 Levenhagen, R. S.; Leister, N. V. (2006). "Spectroscopic analysis of southern B and Be stars". Monthly Notices of the Royal Astronomical Society. 371 (1): 252–262. arXiv:astro-ph/0606149. Bibcode:2006MNRAS.371..252L. doi:10.1111/j.1365-2966.2006.10655.x. S2CID 16492030.
  5. ↑ Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 3. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1982mcts.book.....H.
  6. ↑ Hoffleit, D.; Warren, Jr., W. H. "HR 1956 database entry". The Bright Star Catalogue (5th Revised Ed. (Preliminary Version) ed.). Retrieved 2009-04-21. CDS ID V/50
  7. 1 2 Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. GCVS 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 255195566.
  8. ↑ Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institute of Washington D.C. Bibcode:1953GCRV..C......0W.
  9. ↑ Kaler, James B. "Phact". STARS. Retrieved 2026-05-17.
  10. 1 2 3 Arcos, C.; et al. (January 3, 2018). "Stellar parameters and H α line profile variability of Be stars in the BeSOS survey". Monthly Notices of the Royal Astronomical Society. 474 (4): 5287–5299. arXiv:1711.08675. Bibcode:2018MNRAS.474.5287A. doi:10.1093/mnras/stx3075. ISSN 0035-8711.
  11. ↑ Balona, Luis A.; Ozuyar, Dogus (2021). "TESS Observations of be Stars: General Characteristics and the Impulsive Magnetic Rotator Model". The Astrophysical Journal. 921 (1): 5. arXiv:2008.06288. Bibcode:2021ApJ...921....5B. doi:10.3847/1538-4357/ac1a77.
  12. 1 2 3 Oudmaijer, R. D.; et al. (October 2008). "Sub-milliarcsecond precision spectro-astrometry of Be stars". Astronomy and Astrophysics. 489 (2): 627–631. arXiv:0807.3673. Bibcode:2008A&A...489..627O. doi:10.1051/0004-6361:20079117. S2CID 10317142.
  13. ↑ "alf Col". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 21, 2009.
  14. ↑ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
  15. ↑ Mamajek, Eric. "IAU Catalog of Star Names". University of Rochester. Retrieved 28 July 2016.
  16. 1 2 Hoffleit, D.; Warren, Jr., W. H. "Note of HR 1956 database entry". The Bright Star Catalogue (5th Revised Ed. (Preliminary Version) ed.). Retrieved 2009-04-21. CDS ID V/50
  17. ↑ Davis, Jr., G. A. (1971). Pronunciations, Derivations, and Meanings of a Selected List of Star Names (Reprint ed.). Cambridge, MA: Sky Publishing Corp. p. 11.
  18. ↑ Kunitzsch, P. (1959). Arabische Sternnamen in Europa. Wiesbaden: Otto Harrassowitz. pp. 191–192.
  19. ↑ Laffitte, R. (2005). Héritages arabes: Des noms arabes pour les étoiles (2éme revue et corrigée ed.). Paris: Librairie Orientaliste Paul Geunthner / Les Cahiers de l'Orient. p. 223.
  20. ↑ Kunitzsch, P.; Smart, T. (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, MA: Sky Pub. p. 30. ISBN 978-1-931559-44-7.
  21. ↑ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 167. Retrieved 2026-05-17. ISBN 0-486-21079-0.
  22. ↑ "IAU Working Group on Star Names (WGSN)". International Astronomical Union. Archived from the original on 10 June 2016. Retrieved 22 May 2016.
  23. ↑ Mamajek, Eric. "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). University of Rochester. Retrieved 28 July 2016.
  24. ↑ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  25. ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2011-01-30 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
  26. ↑ Allen, Richard Hinckley. "Columbae". Star Names — Their Lore and Meaning. Retrieved 2026-05-17.
  27. ↑ 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:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
  28. ↑ Dommanget, J.; Nys, O. (2002). "CCDM J05396-3404 database entry". Catalogue of the Components of Double and Multiple Stars. Retrieved 2009-04-21.