19 Sextantis
K-type giant star; Sextans
19 Sextantis (HD 88547; HR 4004; 34 G. Sextantis ), or simply 19 Sex , is a solitary star [13] located in the equatorial constellation Sextans . It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.78.[2] Gaia DR3 parallax measurements imply a distance of 516 light-years [1] and it is currently receding with a heliocentric radial velocity of 31.8 km/s .[7] At its current distance, 19 Sex's brightness is diminished by an interstellar extinction of 0.17 magnitudes .[14]
19 Sex has a stellar classification of K1 III,[4] indicating that it is an evolved K-type giant star that has ceased hydrogen fusion at it core and it has left the main sequence . It has also been given a slightly hotter class of K0 III.[5] Stellar evolution models from Stock et al. (2018) model it to be a red giant branch star (100% chance)[3] that is currently fusing a hydrogen shell around an inert helium core. It has 88% the mass of the Sun but at the age of 7.94 billion years ,[3] it has expanded to 23.13 times the radius of the Sun .[8] It radiates 241 times the luminosity of the Sun [1] from its photosphere at an effective temperature of 4,576 K .[9] 19 Sex is metal deficient with an iron abundance of [Fe/H] = −0.53 or 29.5% of the Sun 's[10] and it spins modestly with a projected rotational velocity of 2.5 km/s .[4]
References
^ a b c d e f g Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 . Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 . S2CID 244398875 .
Gaia DR3 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 . S2CID 17128864 .
^ a b c d e Stock, Stephan; Reffert, Sabine; Quirrenbach, Andreas (August 2018). "Precise radial velocities of giant stars: X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search" . Astronomy & Astrophysics . 616 : A33. arXiv :1805.04094 . Bibcode :2018A&A...616A..33S . doi :10.1051/0004-6361/201833111 . ISSN 0004-6361 . S2CID 247657118 .
^ a b c d Henry, Gregory W.; Fekel, Francis C.; Henry, Stephen M.; Hall, Douglas S. (September 2000). "Photometric Variability in a Sample of 187 G and K Giants" . The Astrophysical Journal Supplement Series . 130 (1): 201–225. Bibcode :2000ApJS..130..201H . doi :10.1086/317346 . ISSN 0067-0049 .
^ a b Adams, Walter S.; Joy, Alfred H.; Humason, Milton L.; Brayton, Ada Margaret (April 1935). "The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars" . The Astrophysical Journal . 81 : 187. Bibcode :1935ApJ....81..187A . doi :10.1086/143628 . eISSN 1538-4357 . ISSN 0004-637X . S2CID 121056016 .
^ 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 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 .
^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (April 8, 2004). "The angular sizes of dwarf stars and subgiants: Surface brightness relations calibrated by interferometry" . Astronomy & Astrophysics . 426 (1): 297–307. arXiv :astro-ph/0404180 . Bibcode :2004A&A...426..297K . doi :10.1051/0004-6361:20035930 . eISSN 1432-0746 . ISSN 0004-6361 . S2CID 6077801 .
^ a b Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List" . The Astronomical Journal . 158 (4): 138. arXiv :1905.10694 . Bibcode :2019AJ....158..138S . doi :10.3847/1538-3881/ab3467 . eISSN 1538-3881 . hdl :1721.1/124721 . S2CID 166227927 .
^ a b Hekker, S.; Meléndez, J. (December 2007). "Precise radial velocities of giant stars: III. Spectroscopic stellar parameters" . Astronomy & Astrophysics . 475 (3): 1003–1009. arXiv :0709.1145 . Bibcode :2007A&A...475.1003H . doi :10.1051/0004-6361:20078233 . ISSN 0004-6361 . S2CID 10436552 .
^ 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 .
^ "*19 Sex" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved January 13, 2024 .
^ Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems" . Monthly Notices of the Royal Astronomical Society . 389 (2): 869–879. arXiv :0806.2878 . Bibcode :2008MNRAS.389..869E . doi :10.1111/j.1365-2966.2008.13596.x . eISSN 1365-2966 . ISSN 0035-8711 . S2CID 14878976 .
^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars" . Monthly Notices of the Royal Astronomical Society . 472 (4): 3805–3820. arXiv :1709.01160 . Bibcode :2017MNRAS.472.3805G . doi :10.1093/mnras/stx2219 . eISSN 1365-2966 . ISSN 0035-8711 . S2CID 118879856 .