The system had a traditional nameMarkab,[13] from theArabic مركب,markab meaning "something to ride".[14] It was often spelledMarkeb[15] to distinguish it from similarly named stars such asAlpha Pegasi. In 2016, the IAU organized aWorking Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN approved the nameMarkeb for Kappa Velorum on 5 September 2017.Markab had previously been approved for Alpha Pegasi on 30 June 2016. Both are now included in the List of IAU-approved Star Names.[10]
Kappa Velorum is aspectroscopic binary system consisting of a pair of stars that complete anorbit around each other with aperiod of 116.65 days and aneccentricity of 0.19. Because the individual stars have not been resolved, further details of the orbit have not yet been determined.[5] The combinedstellar classification of the pair is B2 IV,[2] which matches the class of aB-typesubgiant star that has exhausted the hydrogen at its core and begun to evolve into agiant. The primary is about nine times more massive than the Sun, with aphotospheric radius twelve times larger, irradiating 13,000 times more luminosity than the Sun at aneffective temperature of18,000 K,[6] which give Kappa Velorum A the blue-white hue typical ofB-type stars.[19] Nothing is known about the secondary, yet.[7]
The system is only a couple of degrees from the southcelestial pole ofMars, so it could therefore be considered the southern polar star of that planet.[citation needed] Due toprecession of the equinoxes, it will be the closest bright star of note to the south celestial pole of Earth in the period surrounding 9000 AD.[citation needed]
Analysis of thespectrum of Kappa Velorum showsabsorption lines due to theinterstellar medium between Earth and the star. Observation of these features over many years has shown that the lines vary in strength, probably caused by a small dense cloud extending 102–103au moving across the line of sight.[20][21]
^abcdefDenoyelle, J. (March 1977), "The spatial distribution of young stars in Vela (l = 257 to 284 )",Astronomy and Astrophysics Supplement Series,27:343–365,Bibcode:1977A&AS...27..343D
^Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.).Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30.Determination of Radial Velocities and Their Applications. Vol. 30. University of Toronto:International Astronomical Union. p. 57.Bibcode:1967IAUS...30...57E.
^Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets".arXiv:1012.0707 [astro-ph.SR].
^"The Colour of Stars",Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived fromthe original on 2013-12-03, retrieved2012-01-16
"The path of the Southern Celestial Pole": The System of W. B. Yeats's A Vision[1] Diagram of the southern precession circle, showing Markeb as the South Pole Star in 9000 AD.
