20 Canum Venaticorum
{{Short description|Star in the constellation Canes Venatici}}
{{Starbox begin
| name = 20 Canum Venaticorum
}}
{{Starbox image
| image = 250px
| caption = A light curve for AO Canum Venaticorum, plotted from TESS data
}}
{{Starbox observe
| epoch = J2000
| constell = Canes Venatici
| dec = {{DEC|+40|34|21.3875}}
}}
{{Starbox character
| type =
| class = {{nowrap|A9 II mF2}}
| u-b =
| variable = δ Sct
}}
{{Starbox astrometry
| radial_v = {{Val|9.32|0.16}}
| parallax = 13.7210
| p_error = 0.1581
| absmag_v =
}}
{{Starbox detail
| source =
| temperature = {{Val|7314|42|fmt=commas}}
}}
{{Starbox catalog
| names = {{odlist | V=AO Canum Venaticorum | F=20 CVn | BD=+41°2380 | FK5=494 | HD=115604 | HIP=64844 | HR=5017 | SAO=44549 | GC=18000 }}
}}
{{Starbox reference
| Simbad = 20+CVn
}}
{{Starbox end}}
20 Canum Venaticorum is a single 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 an apparent visual magnitude around +4.7. The star is moving further from the Earth with a heliocentric radial velocity of +9 km/s. Eggen (1971) listed this star as a member of the Hyades Stream.
This star has a stellar classification of {{nowrap|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. Earlier, Morgan and Abt (1972) assigned it a giant star class of F3 III. It has also been listed as a spectral standard for class F3 III.
William Henry Wehlau et al. announced that the star's brightness varies, in 1966. It is classified as a Delta Scuti variable with a single radial pulsation mode providing the best fit to the observed variation. Its brightness varies from magnitude +4.70 to +4.75 with a period of 2.92 hours.
20 Canum Venaticorum is 750 million years old with 2.43 times the mass of the Sun and five times the Sun's radius. It is radiating 63 times the Sun's luminosity from its photosphere at an effective temperature of 7,314 K.
References
{{reflist|refs=
{{cite simbad | title=20 CVn | access-date=2018-07-26| mode=cs2 | postscript=. }}
{{cite DR2|1524913024455109632}}
| title=Luminosities and Motions of the F-Type Stars. I. Luminosity and Metal Abundance Indices for Disk Population Stars
| last1=Eggen | first1=O. J. | postscript=.
| journal=Publications of the Astronomical Society of the Pacific
| volume=83 | issue=496 | page=741 | date=December 1971
| doi=10.1086/129211 | bibcode=1971PASP...83..741E | s2cid=119993774 }}
| last1=Wehlau | first1=W. H. | last2=Chen | first2=S. C. N. | last3=Symonds | first3=G.
| title=Light Variability of 20 Canum Venaticorum | journal=Information Bulletin on Variable Stars
| date=July 1966 | volume=143 | pages=1-2 | bibcode=1966IBVS..143....1W }}
| display-authors=1 | last1=Samus | first1=N. N.
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| bibcode=2017ARep...61...80S | postscript=. | doi=10.1134/s1063772917010085| s2cid=125853869 }}
| title=20 CVn: A monoperiodic radially pulsating delta Scuti star
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| title=Carbon and Oxygen Abundances across the Hertzsprung Gap
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| volume=791 | issue=1 | id=58 | pages=12 | date=August 2014
| doi=10.1088/0004-637X/791/1/58 | bibcode=2014ApJ...791...58A
| arxiv=1407.2157 | s2cid=119104634 | postscript=. }}
| title=Validation of the new Hipparcos reduction
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| journal=Astronomy and Astrophysics
| volume=474 | issue=2 | pages=653–664 | date=2007
| arxiv=0708.1752 | bibcode=2007A&A...474..653V
| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}
| display-authors=1 | last1=Gray | first1=R. O.
| last2=Napier | first2=M. G. | last3=Winkler | first3=L. I.
| title=The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars
| journal=The Astronomical Journal
| volume=121 | issue=4 | pages=2148 | year=2001
| bibcode=2001AJ....121.2148G | postscript=. | doi=10.1086/319956| doi-access= }}
| title=Abundances in the Local Region. I. G and K Giants
| last1=Luck | first1=R. Earle
| journal=Astronomical Journal
| volume=150 | issue=3 | at=88 | year=2015
| arxiv=1507.01466 | bibcode=2015AJ....150...88L
| doi=10.1088/0004-6256/150/3/88 | s2cid=118505114 | postscript=. }}
{{citation | display-authors=1
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| last3=Stefanik | first3=Robert P. | last4=Fogel | first4=Jeffrey
| title=Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity
| journal=The Astronomical Journal | postscript=.
| volume=135 | issue=1 | pages=209–231 | date=January 2008
| doi=10.1088/0004-6256/135/1/209 | bibcode=2008AJ....135..209M | doi-access=free }}
| last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A.
| title=A catalogue of multiplicity among bright stellar systems
| journal=Monthly Notices of the Royal Astronomical Society
| volume=389 | issue=2 | pages=869–879 | year=2008
| arxiv=0806.2878 | bibcode=2008MNRAS.389..869E
| doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | s2cid=14878976 | postscript=. }}
| display-authors=1 | last1=Royer | first1=F.
| last2=Grenier | first2=S. | last3=Baylac | first3=M.-O.
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| title=Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i
| journal=Astronomy and Astrophysics
| volume=393 | pages=897–911 | date=October 2002
| doi=10.1051/0004-6361:20020943 | bibcode=2002A&A...393..897R
| arxiv=astro-ph/0205255 | s2cid=14070763 | postscript=. }}
| last1=Morgan | first1=W. W. | last2=Abt | first2=H. A.
| title=The spectral classification of the F stars of intermediate luminosity
| journal=Astronomical Journal | postscript=.
| volume=77 | pages=35–37 | date=February 1972
| doi=10.1086/111242 | bibcode=1972AJ.....77...35M | doi-access= }}
}}
{{Stars of Canes Venatici}}
{{DEFAULTSORT:20 Canum Venaticorum}}
Category:Delta Scuti variables