B-type main-sequence star; Octans
HD 169904
Location of HD 204904 on the map (circled)
Observation dataEpoch J2000.0 Equinox J2000.0 (ICRS )
Constellation
Octans
Right ascension 18h 42m 14.42015s [ 1]
Declination
−81° 48′ 29.2064″[ 1]
Apparent magnitude (V)6.26± 0.01[ 2]
Characteristics
Evolutionary stage
main sequence star [ 3]
Spectral type
B8 V[ 4]
U−B color index
−0.37[ 5]
B−V color index
−0.13[ 5]
Variable type
suspected[ 6]
Astrometry Radial velocity (Rv )−6.0± 4.3[ 7] km/s Proper motion (μ) RA: +13.838 mas /yr [ 1] Dec.: −16.605 mas /yr [ 1] Parallax (π)6.7598± 0.0413 mas [ 1] Distance 482 ± 3 ly pc ) Absolute magnitude (MV )+0.19[ 8] Details Mass 3.25± 0.06[ 3] M ☉ Radius 2.42± 0.12[ 9] R ☉ Luminosity 141+14 −13 [ 3] L ☉ Surface gravity (log g )4.20[ 10] cgs Temperature 13,622[ 11] K Metallicity [Fe/H] −0.18[ 12] dex Rotational velocity (v sin i )123[ 13] Other designations 35 G. Octantis [ 14] NSV 24510CD −81°693CPD −81°813GC 25366HD 169904HIP 91723HR 6912SAO 258804TIC 351920521[ 15] Database references SIMBAD data
HD 169904 (HR 6912; 35 G. Octantis ) is a solitary star located in the southern circumpolar constellation Octans . It has an apparent magnitude of 6.26,[ 2] naked eye visibility, even under ideal conditions . Gaia DR3 parallax measurements imply a distance of 482 light-years [ 1] radial velocity of km/s [ 7] magnitudes due to interstellar extinction [ 16] absolute magnitude of +0.19.[ 8]
HD 169904 has a stellar classification of B8 V,[ 4] B-type main-sequence star that is generating energy via hydrogen fusion at its core . It has 3.25 times the mass of the Sun [ 3] radius of the Sun .[ 9] luminosity of the Sun [ 3] photosphere at an effective temperature of K [ 11] night sky . HD 169904 is metal deficient with an iron abundance of [Fe/H] = −0.18 or 66.1% of the Sun 's,[ 12] projected rotational velocity of km/s [ 13] main sequence lifetime.[ 3]
The object was listed as a suspected variable star based on photometric observations,[ 6] [ 17]
^ a b c d e 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 f Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars IV: Evolution of rotational velocities" . Astronomy & Astrophysics . 537 : A120. arXiv :1201.2052 Bibcode :2012A&A...537A.120Z . doi :10.1051/0004-6361/201117691 eISSN 1432-0746 . ISSN 0004-6361 . S2CID 55586789 . ^ a b Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars: Declinations −90° to −53° . Vol. 1. 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 Grønbech, B.; Olsen, E. H. (July 1976). "Four-color uvby photometry for bright O to G0 type stars south of declination +10 ". Astronomy and Astrophysics Supplement Series . 25 : 213– 270. Bibcode :1976A&AS...25..213G . ISSN 0365-0138 . S2CID 118304388 . ^ 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 . eISSN 1562-6873 . ISSN 1063-7737 . S2CID 119231169 . ^ a b 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 . eISSN 1562-6873 . ISSN 1063-7737 . S2CID 119257644 . ^ 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 . ^ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (15 June 2017). "Fundamental parameters and infrared excesses of Tycho–Gaia stars" . Monthly Notices of the Royal Astronomical Society . 471 (1): 770– 791. arXiv :1706.02208 Bibcode :2017MNRAS.471..770M . doi :10.1093/mnras/stx1433 eISSN 1365-2966 . ISSN 0035-8711 . S2CID 73594365 . ^ a b Philip, A. G. D.; Egret, D. (May 1980). "An analysis of the Hauck-Mermillod catalogue of homogeneous four-color data. II". Astronomy and Astrophysics Supplement Series . 40 : 199– 205. Bibcode :1980A&AS...40..199P . ISSN 0365-0138 . ^ a b Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5" . Astronomy & Astrophysics . 658 : A91. arXiv :2111.01860 Bibcode :2022A&A...658A..91A . doi :10.1051/0004-6361/202142369 eISSN 1432-0746 . ISSN 0004-6361 . ^ a b Levato, Hugo; Grosso, Mónica (June 2004). "New Projected Rotational Velocities of All Southern B-type Stars of the Bright Star Catalogue" . Symposium - International Astronomical Union . 215 : 51– 52. Bibcode :2004IAUS..215...51L . doi :10.1017/S0074180900195191 ISSN 0074-1809 . ^ 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 . ^ "HD 169904" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved November 4, 2023 .^ 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 . ^ Samus, N. N.; Durlevich, O. V. (November 2004). "VizieR Online Data Catalog: Combined General Catalogue of Variable Stars (Samus+ 2004)". VizieR Online Data Catalog : II/250. Bibcode :2004yCat.2250....0S .
