20 Canum Venaticorum
Star in the constellation Canes Venatici
20 Canum Venaticorum is a single[ 11] variable star in the northern constellation of Canes Venatici , located 238 light years from the Sun. This object has the variable star designation AO Canum Venaticorum ; 20 Canum Venaticorum is the Flamsteed designation . It is visible to the naked eye as a faint, white-hued star with a baseline apparent visual magnitude of +4.72.[ 3] The star is moving further from the Earth with a heliocentric radial velocity of +9 km/s.[ 6] Eggen (1971) listed this star as a member of the Hyades Stream .[ 12]
This star has a stellar classification of A9 II mF2 , which indicates the hydrogen line matches an A-type bright giant but the metal lines are closer to an F-type star . However, it does not appear to be an Am star as the Calcium K line is normal.[ 4] Earlier, Morgan and Abt (1972) assigned it a giant star class of F3 III.[ 13] It is classified as a Delta Scuti type variable star with a single radial pulsation mode providing the best fit to the observed variation.[ 5] Its brightness varies from magnitude +4.70 to +4.75 with a period of 2.92 hours.[ 14]
20 Canum Venaticorum is 750[ 3] million years old with 2.43[ 3] times the mass of the Sun and 4[ 7] time the Sun's radius . It is radiating 63[ 3] times the Sun's luminosity from its photosphere at an effective temperature of 7,314 K.[ 3]
References
^ "MAST: Barbara A. Mikulski Archive for Space Telescopes" . Space Telescope Science Institute. Retrieved 8 December 2021 .
^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653– 664, arXiv :0708.1752 , Bibcode :2007A&A...474..653V , doi :10.1051/0004-6361:20078357 , S2CID 18759600 .
^ a b c d e f g h i j k Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal , 150 (3), 88, arXiv :1507.01466 , Bibcode :2015AJ....150...88L , doi :10.1088/0004-6256/150/3/88 , S2CID 118505114 .
^ a b Gray, R. O.; et al. (2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars", The Astronomical Journal , 121 (4): 2148, Bibcode :2001AJ....121.2148G , doi :10.1086/319956 .
^ a b Chadid, M.; et al. (August 2001), "20 CVn: A monoperiodic radially pulsating delta Scuti star", Astronomy and Astrophysics , 375 : 113– 121, Bibcode :2001A&A...375..113C , doi :10.1051/0004-6361:20010809 .
^ a b 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 Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal , 135 (1): 209– 231, Bibcode :2008AJ....135..209M , doi :10.1088/0004-6256/135/1/209 .
^ Adamczak, Jens; Lambert, David L. (August 2014), "Carbon and Oxygen Abundances across the Hertzsprung Gap", The Astrophysical Journal , 791 (1): 12, arXiv :1407.2157 , Bibcode :2014ApJ...791...58A , doi :10.1088/0004-637X/791/1/58 , S2CID 119104634 , 58.
^ Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics , 393 : 897– 911, arXiv :astro-ph/0205255 , Bibcode :2002A&A...393..897R , doi :10.1051/0004-6361:20020943 , S2CID 14070763 .
^ "20 CVn" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2018-07-26 .
^ 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– 879, arXiv :0806.2878 , Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x , S2CID 14878976 .
^ Eggen, O. J. (December 1971), "Luminosities and Motions of the F-Type Stars. I. Luminosity and Metal Abundance Indices for Disk Population Stars", Publications of the Astronomical Society of the Pacific , 83 (496): 741, Bibcode :1971PASP...83..741E , doi :10.1086/129211 , S2CID 119993774 .
^ Morgan, W. W.; Abt, H. A. (February 1972), "The spectral classification of the F stars of intermediate luminosity", Astronomical Journal , 77 : 35– 37, Bibcode :1972AJ.....77...35M , doi :10.1086/111242 .
^ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports , 5.1, 61 (1): 80– 88, Bibcode :2017ARep...61...80S , doi :10.1134/s1063772917010085 , S2CID 125853869 .