18 Andromedae

Blue-hued star in the constellation Andromeda Andromeda constellation map.svg center 260 right Red circle.svg 10 18 Andromedae 854 112 Location of 18 Andromedae (circled) J2000 Andromeda 23 39 08.33166 +50 28 18.2375 5.350 main sequence B9 Ve −0.110 +9.9 2.2 −17.057 −2.041 7.7914 0.0633 3.09 0.06 3.61 0.08 146.6 14.1 12.9 10351 50 commas 3.632 0.014 183 18 And +49°4180 3897 222304 116709 8967 35642 42060 18+And 18 Andromedae, abbreviated 18 And, is a single star in the northern constellation of Andromeda. 18 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 5.350. The annual parallax shift of 7.8 mas can be used to estimate a distance of 419 light years. It is moving further from the Earth with a heliocentric radial velocity of +10 km/s. This is a B-type main-sequence star with a stellar classification of B9 Ve, where the 'e' notation indicates this is a Be star. The stellar spectrum of 18 And displays an emission line in the hydrogen Brackett series due to a dense gaseous circumstellar envelope. The star is spinning rapidly with a projected rotational velocity of 183 km/s and has about three times the mass of the Sun. It is radiating 147 times the Sun's luminosity from its photosphere at an effective temperature of 10,351 K. The star has about 3.61 times the radius of the Sun. References 18 And September 20, 2018 1944475838303255424 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 . Simultaneous K- and L-band spectroscopy of Be stars: circumstellar envelope properties from hydrogen emission lines 1 Granada A. Arias M. L. Cidale L. S. The Astronomical Journal . 139 5 1983–1992 May 2010 10.1088/0004-6256/139/5/1983 2010AJ....139.1983G free 11336/9567 free Soubiran Caroline Le Campion Jean-François Brouillet Nathalie Chemin Laurent The PASTEL catalogue: 2016 version Astronomy & Astrophysics 1 591 A118 2016 2016A&A...591A.118S 10.1051/0004-6361/201628497 1605.07384 119258214 . Rotational velocities of A-type stars. IV. Evolution of rotational velocities Zorec J. Royer F. Astronomy & Astrophysics 537 A120 2012 2012A&A...537A.120Z 1201.2052 10.1051/0004-6361/201117691 55586789 . Gontcharov G. A. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system Astronomy Letters . 32 11 759–771 November 2006 10.1134/S1063773706110065 2006AstL...32..759G 1606.08053 119231169 Category:B-type main-sequence stars Category:Be stars Category:Andromeda (constellation) Category:Durchmusterung objects Andromedae, 18 222304 116709 8967