Star in the constellation of Lyra
μ Lyrae , Latinized as Mu Lyrae , is a solitary[ 8] star in the northern constellation Lyra . It has the traditional name Alathfar , from the Arabic الأظفار al-ʼaẓfār "the talons (of the swooping eagle)", a name it shares with Eta Lyrae [ 9] IAU ).[ 10] apparent visual magnitude of 5.11.[ 2] light years distant from the Sun based on parallax ,[ 1] radial velocity of −24 km/s.[ 2]
This object has evolved off the main sequence ,[ 3] subgiant with a stellar classification of A0 IV.[ 4] projected rotational velocity of 165 km/s.[ 3] equatorial bulge that is an estimated 17% larger than the polar radius.[ 6] mass of the Sun and about 5.8 times the Sun's radius . It is radiating 200 times the Sun's luminosity from its photosphere at an effective temperature of 9,016 K.[ 3]
Notes
^ Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K :
(
5
,
772
9
,
016
)
4
⋅
200
=
5.80
R
⊙
.
{\displaystyle {\sqrt {{\biggl (}{\frac {5,772}{9,016}}{\biggr )}^{4}\cdot 200}}=5.80\ R_{\odot }.}
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 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 c d e Zorec, J.; Royer, F. (January 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 Van Belle, Gerard T.; von Braun, Kaspar (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal . 694 (2): 1085– 1098. arXiv :0901.1206 Bibcode :2009ApJ...694.1085V . doi :10.1088/0004-637X/694/2/1085 . S2CID 18370219 . ^ Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data . Bibcode :1986EgUBV........0M . ^ a b van Belle, Gerard T. (March 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 ^ "mu Lyr" . SIMBAD Centre de données astronomiques de Strasbourg .^ 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 . ^ Allen, Richard Hinckley (2018). Star-Names and Their Meanings ISBN 978-0-344-21405-9 ^ "Naming Stars" . IAU.org. Retrieved 16 December 2017 .
External links
Kaler, James B. (October 7, 2011). "Al Athfar" . STARS . Retrieved 2019-09-25 .
