Short description: Star in the constellation Aquarius
20 Aquarii, abbreviated 20 Aqr, is a star in the constellation Aquarius. 20 Aquarii is the Flamsteed designation. It is a dim star with an apparent visual magnitude of 6.38.[2] Based upon an annual parallax shift of 15.34 mas,[1] it is located 213 light years away but is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.[5] The star is predicted to come to within 110 light-years in around 1.9 million years.[2]
This is an F-type main-sequence star with a stellar classification of F0 V.[3] (Cowley and Fraquelli [1974] had given it a class of F0 III.)[4] It is a suspected[9] chemically peculiar Am star showing metallic lines.[10] It is 761[6] million years old with a high projected rotational velocity of 92 km/s.[7] The star has 1.52[6] times the mass of the Sun and is radiating 9[2] times the Sun's luminosity from its photosphere at an effective temperature of about 7,314 K.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode: 1999MSS...C05....0H.
- ↑ 4.0 4.1 Cowley, A.; Fraquelli, D. (1974), "MK Spectral Types for Some Bright F Stars", Publications of the Astronomical Society of the Pacific 86 (509): 70, doi:10.1086/129562, Bibcode: 1974PASP...86...70C.
- ↑ 5.0 5.1 Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 7.0 7.1 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, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R.
- ↑ "20 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=20+Aqr.
- ↑ Renson, P.; Manfroid, J. (2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics 498 (3): 961, doi:10.1051/0004-6361/200810788, Bibcode: 2009A&A...498..961R.
- ↑ Paunzen, E. et al. (February 2013), "A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society 429 (1): 119–125, doi:10.1093/mnras/sts318, Bibcode: 2013MNRAS.429..119P.
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