}}{{Starbox reference
| Simbad = 19+CVn
}}{{Starbox end}}19 Canum Venaticorum is a binary star[13] system in the northern constellation of Canes Venatici, located approximately 238 light years from Sun based on its parallax. It is dimly visible to the naked eye as a white-hued star with an apparent visual magnitude of 5.77.[3] The pair orbit each other with a period of 219.2 years and an eccentricity of 0.686.[13] The system is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[8]The magnitude +5.87 primary, component A, is a A-type main-sequence star with a stellar classification of A7 V.[4] It is 366[17] million years old with twice[5] the mass of the Sun and 2.5[15] times the Sun's radius. The star is radiating 25.5[5] times the Sun's luminosity from its photosphere at an effective temperature of 8,048 K.[17] It has a high rate of spin, showing a projected rotational velocity of 110 km/s.[5] As of 2012, its companion, designated component B, is a magnitude 9.48 star located {{Val|0.60|u=arcseconds}} from the primary along a position angle of 58°.[4]
References
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7. ^1 2 3 4 5 {{cite journal | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | bibcode=2015ApJ...804..146D | arxiv=1501.03154 | doi=10.1088/0004-637X/804/2/146 }}
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9. ^1 2 3 4 5 6 7 {{cite journal | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities | last1=Zorec | first1=J. | last2=Royer | first2=F. | last3=Asplund | first3=Martin | last4=Cassisi | first4=Santi | last5=Ramirez | first5=Ivan | last6=Melendez | first6=Jorge | last7=Bensby | first7=Thomas | last8=Feltzing | first8=Sofia | display-authors=1 | journal=Astronomy and Astrophysics | volume=537 | pages=A120 | year=2012 | bibcode=2012A&A...537A.120Z | arxiv=1201.2052 | doi=10.1051/0004-6361/201117691 }}