HD 198404
Star with an optical companion
HD 198404 (HR 7975 ) is a star in the equatorial constellation Delphinus . It has an apparent magnitude of 6.19,[ 2] allowing it to be faintly seen with the naked eye . Parallax measurements place the object at a distance of 395 light years [ 1] and it is approaching the Solar System with a heliocentric radial velocity of −21.6 km/s .[ 5]
HD 198404 has a simple stellar classification of K0,[ 3] indicating that it is a K-type star . Its enlarged diameter of 10.54 R ☉ [ 8] and its low surface gravity [ 7] suggest that it has evolved away from the main sequence to become a giant star .[ 7] HD 198404 has 3.12 times the mass of the Sun [ 7] and radiates at 56 times the luminosity of the Sun [ 9] from its photosphere at an effective temperature of 4,809 K ,[ 10] giving it a yellowish orange hue. The star is metal enriched, having an iron abundance 48% greater than that of the Sun .[ 7]
HD 198404 has an optical companion located 78.2″ away along a position angle of 127° (as of 2014).[ 13]
References
^ a b c d e Brown, A. G. A. ; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties" . Astronomy & Astrophysics . 649 : A1. arXiv :2012.01533 . Bibcode :2021A&A...649A...1G . doi :10.1051/0004-6361/202039657 . S2CID 227254300 . (Erratum: doi :10.1051/0004-6361/202039657e ) . Gaia EDR3 record for this source at VizieR .
^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics . 355 : L27 – L30 . Bibcode :2000A&A...355L..27H . ISSN 0004-6361 .
^ a b Cannon, Annie Jump; Pickering, Edward Charles (1923). "The Henry Draper catalogue : 19h and 20h". Annals of Harvard College Observatory . 98 : 1. Bibcode :1923AnHar..98....1C .
^ a b Cousins, A. W. J. (16 November 1964). "Photometric Data for Stars in the Equatorial Zone (Seventh List)". Monthly Notes of the Astronomical Society of South Africa . 23 : 175. Bibcode :1964MNSSA..23..175C . ISSN 0024-8266 .
^ a b Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters" . Astronomy and Astrophysics . 430 : 165. arXiv :astro-ph/0409579 . Bibcode :2005A&A...430..165F . doi :10.1051/0004-6361:20041272 . S2CID 17804304 .
^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters . 38 (5): 331– 346. arXiv :1108.4971 . Bibcode :2012AstL...38..331A . doi :10.1134/S1063773712050015 . ISSN 1063-7737 . S2CID 119257644 .
^ a b c d e f g Liu, Y. J.; Tan, K. F.; Wang, L.; Zhao, G.; Sato, Bun'ei; Takeda, Y.; Li, H. N. (31 March 2014). "The Lithium Abundances of a Large Sample of Red Giants" . The Astrophysical Journal . 785 (2): 94. arXiv :1404.1687 . Bibcode :2014ApJ...785...94L . doi :10.1088/0004-637X/785/2/94 . eISSN 1538-4357 . ISSN 0004-637X .
^ a b Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3" . Astronomy & Astrophysics . 657 : A7. arXiv :2109.10912 . Bibcode :2022A&A...657A...7K . doi :10.1051/0004-6361/202142146 . eISSN 1432-0746 . ISSN 0004-6361 .
^ a b McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos" . Monthly Notices of the Royal Astronomical Society . 427 (1): 343– 357. arXiv :1208.2037 . Bibcode :2012MNRAS.427..343M . doi :10.1111/j.1365-2966.2012.21873.x . ISSN 0035-8711 .
^ a b Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18" . Astronomy & Astrophysics . 628 : A94. arXiv :1904.11302 . Bibcode :2019A&A...628A..94A . doi :10.1051/0004-6361/201935765 . ISSN 0004-6361 .
^ "HR 7975" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved June 21, 2022 .
^ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino . 1 . Bibcode :1879RNAO....1.....G .
^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog" . The Astronomical Journal . 122 (6): 3466– 3471. Bibcode :2001AJ....122.3466M . doi :10.1086/323920 . ISSN 0004-6256 .