Star in the constellation Leo
54 Leonis is abinary star [ 12] zodiac constellation ofLeo , located around 321[ 3] light years from the Sun. It is visible to the naked eye as a faint, white-hued star with a combinedapparent visual magnitude of 4.30.[ 13] angular separation of″ position angle of 113°.[ 14] AU (79,700 Gm ).[ 9]
The magnitude 4.477[ 2] A-type main-sequence star with astellar classification of A0 V,[ 5] hydrogen fusion at itscore . It has a high rate of spin, showing aprojected rotational velocity of 185 km/s. This is giving the star anoblate shape with anequatorial bulge that is an estimated 8% larger than the polar radius.[ 10] [ 8] [ 8] mass of the Sun and about 2.88[ 9] Sun's radius .
The fainter magnitude 6.29[ 4] [ 5] lines due to rapid rotation. It is spinning with an even higher projected rotational velocity of 250[ 9] [ 9]
Asteroid729 Watsonia occulted HIP 53417 on March 3, 2013 at 01:48.[ 15]
^a b c d e 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 atVizieR .^a b Høg, E.; et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars",Astronomy and Astrophysics ,355 : L27,Bibcode :2000A&A...355L..27H ,doi :10.1888/0333750888/2862 . ^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 atVizieR .^a b c Fabricius, C.; et al. (2002), "The Tycho double star catalogue",Astronomy and Astrophysics ,384 :180– 189,Bibcode :2002A&A...384..180F ,doi :10.1051/0004-6361:20011822 ^a b c d e Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications",Astronomical Journal ,74 :375– 406,Bibcode :1969AJ.....74..375C ,doi :10.1086/110819 . ^a b Becker, Juliette C.; et al. (April 2015), "Extracting Radial Velocities of A- and B-type Stars from Echelle Spectrograph Calibration Spectra",The Astrophysical Journal Supplement Series ,217 (2): 13,arXiv :1503.03874 Bibcode :2015ApJS..217...29B ,doi :10.1088/0067-0049/217/2/29 ,S2CID 33968873 , 29. ^ Pizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases",Astronomy and Astrophysics ,361 :614– 628,Bibcode :2000A&A...361..614P ^a b c d e f Gullikson, Kevin; et al. (2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars",The Astronomical Journal ,152 (2): 40,arXiv :1604.06456 Bibcode :2016AJ....152...40G ,doi :10.3847/0004-6256/152/2/40 S2CID 119179065 . ^a b c d e f g Howe, K. S.; Clarke, C. J. (January 2009), "An analysis of v sin (i) correlations in early-type binaries",Monthly Notices of the Royal Astronomical Society 392 (1):448– 454,Bibcode :2009MNRAS.392..448H ,doi :10.1111/j.1365-2966.2008.14073.x ^a b 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 . ^ "54 Leo" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2019-02-05 .^ 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 . ^ 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 . ^ Mason, Brian D.; et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog",The Astronomical Journal ,122 (6), U. S. Naval Observatory, Washington D.C.:3466– 3471,Bibcode :2001AJ....122.3466M ,doi :10.1086/323920 ^ Pier Paolo Ricci (29 November 2012).Almanacco astronomico 2013 Astronomical almanac 2013 ISBN 978-1-291-21157-3
