Star system in the constellation Orion
15 Orionis is a suspected astrometric binary [ 9] star system in the equatorial constellation of Orion , near the border with Taurus . It is visible to the naked eye as a faint, yellow-white hued star with an apparent visual magnitude of 4.82.[ 2] The system is approximately 340 light years away from the Sun based on parallax . It is moving further from the Earth with a heliocentric radial velocity of +29 km/s,[ 4] having come to within 69 light-years some three million years ago.[ 5]
The primary component is an early F-type subgiant star with a stellar classification of F2 IV,[ 3] a star that has exhausted the hydrogen at its core and has begun to evolve into a giant . It has 3.42[ 6] times the mass of the Sun and 5.9[ 7] times the Sun's radius . The star still has a relatively high rotation rate, showing a projected rotational velocity of 60 km/s.[ 6] It is radiating 300 times the luminosity of the Sun from its expanding photosphere at an effective temperature of 7,161 K.[ 6]
It has one suspected companion, component B, at a separation of 0.3".[ 10]
^ a b c d e Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties" . Astronomy & Astrophysics . 616 . A1. arXiv :1804.09365 . Bibcode :2018A&A...616A...1G . doi :10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR .
^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues . 2237 . Bibcode :2002yCat.2237....0D .
^ a b Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H . 5050 . Bibcode :1995yCat.5050....0H .
^ a b Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity" . The Astronomical Journal . 135 (1): 209–231. Bibcode :2008AJ....135..209M . doi :10.1088/0004-6256/135/1/209 . S2CID 121883397 .
^ a b 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 . Vizier catalog entry
^ a b c d e f g Zorec, J.; Royer, F.; Asplund, Martin; Cassisi, Santi; Ramirez, Ivan; Melendez, Jorge; Bensby, Thomas; Feltzing, Sofia (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics . 537 : A120. arXiv :1201.2052 . Bibcode :2012A&A...537A.120Z . doi :10.1051/0004-6361/201117691 . S2CID 55586789 .
^ a b Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics . 352 : 555–562. arXiv :astro-ph/9911002 . Bibcode :1999A&A...352..555A . Vizier catalog entry
^ a b Wu, Yue; Singh, H. P.; Prugniel, P.; Gupta, R.; Koleva, M. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics . 525 : A71. arXiv :1009.1491 . Bibcode :2011A&A...525A..71W . doi :10.1051/0004-6361/201015014 . S2CID 53480665 .
^ 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 .
^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog" . The Astronomical Journal . 122 (6): 3466. Bibcode :2001AJ....122.3466M . doi :10.1086/323920 . Vizier catalog entry