HD 173780
Star in the constellation Lyra
HD 173780 is a single[ 9] star in the northern constellation Lyra , near the southern constellation border with Hercules . It is an orange-hued star that is faintly visible to the naked eye with an apparent visual magnitude of +4.84.[ 2] This object is located at a distance of approximately 237 light years from the Sun based on parallax , but is drifting closer with a radial velocity of −17 km/s.[ 1]
This is an aging giant star with a stellar classification of K3III.[ 4] It is a red clump giant, indicating it is on the horizontal branch and is generating energy through the fusion of helium at its core.[ 3] The star is 2.4 billion years old with 1.7 times the mass of the Sun .[ 2] With the supply of hydrogen exhausted at its core , it has expanded to 16 times the radius of the Sun . The star is radiating 92 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,468 K.[ 1]
References
^ a b c d e f g h i j 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 d e f 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 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal , 539 (2): 732–741, arXiv :astro-ph/0003329 , Bibcode :2000ApJ...539..732A , doi :10.1086/309278 , S2CID 16673121 .
^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series , 71 : 245, Bibcode :1989ApJS...71..245K , doi :10.1086/191373 .
^ 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 .
^ a b c Wu, Yue; et al. (2010), "Coudé-feed stellar spectral library – atmospheric parameters", Astronomy & Astrophysics , 525 : A71, arXiv :1009.1491 , Bibcode :2011A&A...525A..71W , doi :10.1051/0004-6361/201015014 , S2CID 53480665 .
^ 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 .
^ "HD 173780" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2020-02-07 .
^ 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, arXiv :0806.2878 , Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x , S2CID 14878976 .