Kappa Tucanae
Quadruple star system in the constellation Tucana
Kappa Tucanae , Latinised from, κ Tucanae, is a quadruple[5] star system in the southern constellation Tucana . It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of either +4.25[2] or +4.86,[3] depending on the source. The system is located approximately 68 light years from the Sun based on parallax , and is drifting further away with a radial velocity of +8 km/s.[2]
The system consists of two binary pairs separated by 5.3 arcminutes . The brightest star, Kappa Tucanae A, is a yellow-white F-type subgiant with an apparent magnitude of +5.0. Its binary companion, Kappa Tucanae B, has a magnitude of 7.74 and is located about 6″ away from the primary. It completes an orbit around the primary every 857 years.[7]
The other binary pair, the magnitude +7.8 C, and the magnitude +8.4 D, are closer to one another, at 1.12 arcseconds , or at least 23 astronomical units . They orbit each other once every 86.2 years.
References
^ a b c d e 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 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 Hoffleit, D.; Warren, Jr., W. H. (1991), The Bright Star Catalogue (5th Revised ed.), retrieved 2019-09-16 .
^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal , 122 (6): 3466, Bibcode :2001AJ....122.3466M , doi :10.1086/323920 .
^ 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 :0806.2878 , Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x , S2CID 14878976 .
^ a b c d Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics , 542 : A116, arXiv :1204.2459 , Bibcode :2012A&A...542A.116A , doi :10.1051/0004-6361/201118724 , S2CID 53666672 .
^ a b "Sixth Catalog of Orbits of Visual Binary Stars" . United States Naval Observatory . Archived from the original on 2017-08-01. Retrieved 2017-07-01 .
^ a b Tokovinin, A.; Kiyaeva, O. (2015). "Eccentricity distribution of wide binaries". Monthly Notices of the Royal Astronomical Society . 456 (2): 2070. arXiv :1512.00278 . Bibcode :2016MNRAS.456.2070T . doi :10.1093/mnras/stv2825 .
^ "kap Tuc -- Double or multiple star" , SIMBAD Astronomical Database , Centre de Données astronomiques de Strasbourg , retrieved 2017-04-21 .