1 Scorpii

Star in the constellation Scorpius b Scorpii beta Scorpiiβ Scorpii Scorpius constellation map.svg center 280 right Red circle.svg 10 1 Scorpii 855 405 Location of 1 Scorpii (circled in red) J2000.0 Scorpius 15 50 58.74452 −25 45 04.6649 4.63 B1.5 Vn −0.072 0.003 −3.0 4.7 −14.20 −25.12 6.59 0.27 −1.27 8.3 0.2 3.7 3,890 24,000 310 10.3 5.3 b Sco 1 Sco −25°11131 141637 77635 5885 183854 b Sco 2018-02-21 b+Sco 1 Scorpii, or b Scorpii, is a single star in the southern zodiac constellation of Scorpius. It has an apparent magnitude of 4.63, which is bright enough to be faintly visible to the naked eye on a dark night. The star shows an annual parallax shift of 6.59 mas from Earth's orbit, which equates to a distance of roughly 490 light years. It is a probable (89% chance) member of the Sco OB2 moving group. This is a B-type main-sequence star with a stellar classification of B1.5 Vn, where the 'n' suffix indicates "nebulous" absorption lines being induced by rapid rotation. It has a projected rotational velocity of 310 km/s, which is giving the star an oblate shape with an equatorial bulge that is 13% wider than the polar radius. There is some weak evidence that this is a Be star with a gaseous disk that is being viewed edge-on. 1 Scorpii is a young star at around 10 million years old, with 8.3 times the mass of the Sun and 3.7 times the Sun's radius. The star is radiating 3,890 times the Sun's luminosity from its photosphere at an effective temperature of about 24,000 K. References Validation of the new Hipparcos reduction van Leeuwen F. Astronomy and Astrophysics 474 2 653–664 2007 0708.1752 2007A&A...474..653V 10.1051/0004-6361:20078357 18759600 . XHIP: An extended hipparcos compilation Anderson E. Francis Ch. Astronomy Letters 38 5 331 2012 2012AstL...38..331A 10.1134/S1063773712050015 1108.4971 119257644 . Bright Be-shell stars . 1 Rivinius Th. Štefl S. Baade D. Astronomy and Astrophysics 459 1 November 2006 137−145 10.1051/0004-6361:20053008 2006A&A...459..137R free Eggleton P. P. Tokovinin A. A. A catalogue of multiplicity among bright stellar systems Monthly Notices of the Royal Astronomical Society 389 2 869–879 September 2008 10.1111/j.1365-2966.2008.13596.x free 2008MNRAS.389..869E 0806.2878 14878976 . 1 Rizzuto Aaron Ireland Michael Robertson J. G. Multidimensional Bayesian membership analysis of the Sco OB2 moving group Monthly Notices of the Royal Astronomical Society October 2011 416 4 3108–3117 10.1111/j.1365-2966.2011.19256.x free 2011MNRAS.416.3108R 1106.2857 54510608 . 1 Tetzlaff N. Neuhäuser R. Hohle M. M. A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun Monthly Notices of the Royal Astronomical Society 410 1 190–200 January 2011 10.1111/j.1365-2966.2010.17434.x free 2011MNRAS.410..190T 1007.4883 118629873 . de Bruijne J. H. J. Eilers A.-C. Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project Astronomy & Astrophysics 546 A61 14 October 2012 10.1051/0004-6361/201219219 2012A&A...546A..61D 1208.3048 59451347 . Houk Nancy Smith-Moore M. Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars 4 Ann Arbor 1978 Dept. of Astronomy, University of Michigan 1988mcts.book.....H . Interferometric observations of rapidly rotating stars Belle G. T. The Astronomy and Astrophysics Review 20 51 2012 1 2012A&ARv..20...51V 1204.2572 10.1007/s00159-012-0051-2 119273474 . Herbig Ae/Be Stars in nearby OB Associations Hernández J. S. Calvet N. Hartmann L. Briceño C. S. Sicilia-Aguilar A. Berlind P. The Astronomical Journal 1 2005 129 2 856 2005AJ....129..856H astro-ph/0410494 10.1086/426918 17672346 . Category:B-type main-sequence stars Category:Scorpius Scorpii, b CD-25 11131 Scorpii 1 141637 077635 5885