49 Orionis
Star in the constellation Orion
49 Orionis is a single[ 10] star in the equatorial constellation of Orion . It has the Bayer designation d Orionis , while 49 Orionis is the Flamsteed designation . This object is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.80.[ 2] It is located 141 light years away from the Sun based on parallax ,[ 1] but is drifting closer with a radial velocity of −5 km/s.[ 4]
49 Orionis (center)
In the past 49 Orionis was reported as a spectroscopic binary and an orbit was computed with a period of 445.74 days and an eccentricity of 0.549.[ 11] But it was later determined to be single.[ 10]
This object is an A-type main-sequence star with a stellar classification of A4Vn,[ 3] where the 'n' suffix indicates broadened "nebulous" lines caused by rapid rotation. It is around 284[ 6] million years old with a projected rotational velocity of 186 km/s.[ 8] This spin is giving the star an oblate shape with an equatorial bulge that is an estimated 8% larger than the polar radius.[ 12] The star has 1.8[ 6] times the mass of the Sun and double[ 7] the Sun's radius . It is radiating 22[ 8] times the Sun's luminosity from its photosphere at an effective temperature of 8,416 K.[ 6]
References
^ a b c d e f 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 Gray, R. O.; Garrison, R. F. (July 1989). "The Late A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation" . Astrophysical Journal Supplement . 70 : 623. Bibcode :1989ApJS...70..623G . doi :10.1086/191349 .
^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters . 32 (11): 759–771. arXiv :1606.08053 . Bibcode :2006AstL...32..759G . doi :10.1134/S1063773706110065 . S2CID 119231169 .
^ 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 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal , 804 (2): 146, arXiv :1501.03154 , Bibcode :2015ApJ...804..146D , doi :10.1088/0004-637X/804/2/146 , S2CID 33401607 .
^ 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 c d Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics . 537 : A120. arXiv :1201.2052 . Bibcode :2012A&A...537A.120Z . doi :10.1051/0004-6361/201117691 . S2CID 55586789 . Vizier catalog entry
^ "49 Ori" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-07-29 .
^ a b De Rosa, R. J.; et al. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc" . Monthly Notices of the Royal Astronomical Society . 437 (2): 1216. arXiv :1311.7141 . Bibcode :2014MNRAS.437.1216D . doi :10.1093/mnras/stt1932 . S2CID 88503488 .
^ Abt, Helmut A. (June 1965). "The Frequency of Binaries among Normal A-Type Stars" . Astrophysical Journal Supplement . 11 : 429. Bibcode :1965ApJS...11..429A . doi :10.1086/190120 .
^ Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review , 20 (1): 51, arXiv :1204.2572 , Bibcode :2012A&ARv..20...51V , doi :10.1007/s00159-012-0051-2 , S2CID 119273474 .