Gamma Columbae
Star in the constellation Columba
Gamma Columbae , Latinized from γ Columbae, is a possible wide binary star system[2] in the southern constellation of Columba . It is visible to the naked eye with an apparent visual magnitude of 4.36.[5] Based upon an annual parallax shift of 3.75 mas ,[1] it is located roughly 870 light years from the Sun .
The primary component is an evolved [6] B-type subgiant star with a stellar classification of B2.5 IV.[3] It is a candidate slowly pulsating B-type star with a mean longitudinal magnetic field strength of 94± 28 G .[6] The star has nearly six times the mass of the Sun and close to five times the Sun's girth .[6] It is radiating over 2,000 times the solar luminosity from its outer atmosphere at an effective temperature of 12,904 K.[9] The estimated age of this star is around 24 million years.[11] At this age, it is thought to be the remnant of a once more massive star that just finished hydrogen fusion , and is undergoing structural readjustment. This process is extremely short, on the order of ten thousand years, making it a rare object.[10]
The visual magnitude 12.664[2] companion is a G-type main sequence star with a classification of G8 V.[4] It lies at an angular separation of 33.8 arc seconds from the primary, which corresponds to a projected physical separation of 8,844 AU .[2] Despite the young age of these stars, there has been no X-ray emission detected.[2]
References
^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653–664, arXiv :0708.1752 , Bibcode :2007A&A...474..653V , doi :10.1051/0004-6361:20078357 , S2CID 18759600 .
^ a b c d e f g Gerbaldi, M.; et al. (November 2001), "Binary systems with post-T Tauri secondaries", Astronomy and Astrophysics , 379 : 162–184, Bibcode :2001A&A...379..162G , doi :10.1051/0004-6361:20011298 .
^ a b Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars", Astrophysical Journal , 157 : 313–326, Bibcode :1969ApJ...157..313H , doi :10.1086/150069 .
^ a b Huélamo, N.; et al. (July 2000), "X-ray emission from Lindroos binary systems", Astronomy and Astrophysics , 359 : 227–241, arXiv :astro-ph/0005348 , Bibcode :2000A&A...359..227H .
^ a b c Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1999), "UBVRIJKL photometry of the bright stars", Commission Lunar and Planetary Laboratory , 4 : 99, Bibcode :1966CoLPL...4...99J .
^ a b c d e Hubrig, S.; et al. (April 2009), "New magnetic field measurements of β Cephei stars and slowly pulsating B stars", Astronomische Nachrichten , 330 (4): 317, arXiv :0902.1314 , Bibcode :2009AN....330..317H , doi :10.1002/asna.200811187 , S2CID 17497112 .
^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication , Carnegie Institution for Science , Bibcode :1953GCRV..C......0W , LCCN 54001336 .
^ 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 , S2CID 119257644 .
^ a b 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 :1208.2037 . Bibcode :2012MNRAS.427..343M . doi :10.1111/j.1365-2966.2012.21873.x . S2CID 118665352 .
^ a b c Irrgang, Andreas; Przybilla, Norbert; Meynet, Georges (2022). "γ Columbae as a recently stripped pulsating core of a massive star". Nature Astronomy . 6 (12): 1414–1420. arXiv :2211.00358 . Bibcode :2022NatAs...6.1414I . doi :10.1038/s41550-022-01809-6 . S2CID 253244604 .
^ a b Tetzlaff, N.; et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society , 410 (1): 190–200, arXiv :1007.4883 , Bibcode :2011MNRAS.410..190T , doi :10.1111/j.1365-2966.2010.17434.x , S2CID 118629873 .
^ "gam Col -- Variable Star" , SIMBAD Astronomical Database , Centre de Données astronomiques de Strasbourg , retrieved 2016-12-19 .
External links
Kaler, James B. (January 29, 2016), "Gamma Columbae" , STARS , University of Illinois, retrieved 2016-12-21 .