Star in the constellation Scorpius
HD 161840 is a single,[ 8] star in the southern zodiac constellation of Scorpius . It is faintly visible to the naked eye with an apparent visual magnitude of 4.79.[ 2] parallax shift of mas [ 1] light years from the Sun. It is moving closer with a heliocentric radial velocity of −13 km/s.[ 2]
There has been some uncertainty as to the classification of this stage. Houk (1979) lists a stellar class of B8 Ib/II for HD 161840,[ 3] B-type bright giant /lesser supergiant mix. Multiple studies still use an older classification of B8 V,[ 8] [ 6] [ 4] B-type main-sequence star . Garrison and Gray (1994) assigned it a class of B8 III-IV,[ 9] subgiant /giant star track. It has an estimated 3.93[ 4] mass of the Sun and 3.2[ 5] Sun's radius . The star is radiating 565[ 4] Sun's luminosity from its photosphere at an effective temperature of 11,066 K.[ 4]
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 ^ a b c d e f 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 . ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars , vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode :1982mcts.book.....H . ^ a b c d e f g h Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics , 537 : A120, arXiv :1201.2052 Bibcode :2012A&A...537A.120Z , doi :10.1051/0004-6361/201117691 , S2CID 55586789 . ^ a b Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy & Astrophysics , 367 (3rd ed.): 521– 24, arXiv :astro-ph/0012289 Bibcode :2001A&A...367..521P , doi :10.1051/0004-6361:20000451 , S2CID 425754 . ^ a b Hempel, M.; Holweger, H. (September 2003), "Abundance analysis of late B stars. Evidence for diffusion and against weak stellar winds", Astronomy and Astrophysics , 408 : 1065– 1076, Bibcode :2003A&A...408.1065H , doi :10.1051/0004-6361:20030889 ^ "HD 161840" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved 2018-08-04 .^ a b Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society , 389 (2): 869, arXiv :0806.2878 Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ Garrison, R. F.; Gray, R. O (1994), "The late B-type stars: Refined MK classification, confrontation with stromgren photometry, and the effects of rotation", The Astronomical Journal , 107 : 1556, Bibcode :1994AJ....107.1556G , doi :10.1086/116967 .
