Suspected spectroscopic binary.
HD 92209 (HR 4170 ) is a probable spectroscopic binary [ 10] in the southern circumpolar constellation Chamaeleon . It has an apparent magnitude of 6.29,[ 2] placing it near the max naked eye visibility. Parallax measurements place the system at a distance of 600 light years [ 1] and is currently receding with a heliocentric radial velocity of almost 18 km/s .[ 5]
The visible component has a stellar classification of K2 III,[ 3] indicating that it is a red giant . As a consequence, it has expanded to 14.39 times the radius of the Sun .[ 7] Nevertheless, it has 122% the mass of the Sun [ 6] and shines with a luminosity of 81.3 L ☉ ,[ 8] yielding an effective temperature of 4,460 K [ 8] from its enlarged photosphere , which in turn gives an orange hue. HD 92209 has a metallicity 115% that of the Sun [ 9] and spins leisurely with a projected rotational velocity lower than 1 km/s .[ 10]
^ 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 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0 . Bibcode :1975mcts.book.....H .
^ a b Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory . 4 : 99–110. Bibcode :1966CoLPL...4...99J .
^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters . 32 (11): 759–771. arXiv :1606.08053 . Bibcode :2006AstL...32..759G . doi :10.1134/S1063773706110065 . ISSN 1063-7737 . S2CID 119231169 .
^ a b c 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 .
^ 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 c d Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (January 2020). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era" . Astronomy & Astrophysics . 633 : A34. arXiv :1910.12732 . Bibcode :2020A&A...633A..34C . doi :10.1051/0004-6361/201936360 . eISSN 1432-0746 . ISSN 0004-6361 .
^ a b Eggen, O. J. (February 1994). "Evolved GK stars near the Sun. 2: The young disk population" . The Astronomical Journal . 107 : 594. Bibcode :1994AJ....107..594E . doi :10.1086/116879 . ISSN 0004-6256 .
^ a b c De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars: V. Southern stars⋆⋆⋆" . Astronomy & Astrophysics . 561 : A126. arXiv :1312.3474 . Bibcode :2014A&A...561A.126D . doi :10.1051/0004-6361/201220762 . ISSN 0004-6361 .
^ "HD 92209" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved June 13, 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 .