Ap star in the constellation Apus.
HD 129899 (HIP 72670; 15 G. Apodis ), is a solitary star located in the southern circumpolar constellation Apus , the bird-of-paradise . It has an apparent magnitude of 6.44,[ 2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively far at a distance of 928 light-years based on Gaia DR3 parallax measurements[ 1] and it is receding with a heliocentric radial velocity of 2.5 km/s .[ 6] At its current distance, HD 129899's brightness is heavily diminished by an interstellar extinction of 0.55 magnitudes [ 14] and it has an absolute bolometric magnitude of −1.28.[ 8]
HD 129899 has a stellar classification of ApSi,[ 5] indicating that it is an Ap star with an overabundance of silicon in its spectrum. It has 3.43 times the mass of the Sun [ 4] and 4.95 times the radius of the Sun .[ 9] It radiates 190 times the luminosity of the Sun from its photosphere at an effective temperature of 10,617 K ,[ 10] giving it a bluish-white hue when viewed in the night sky . It has a near solar metallicity , having an iron abundance of [Fe/H] = −0.01 or 97.7% of the Sun 's.[ 11] At the age of 229 million years , HD 129899 has completed 95% of its main sequence lifetime.[ 4] Unlike most chemically peculiar stars , HD 129899 spins rapidly with a rotational velocity of 199 km/s .[ 10]
The object was observed to be an Alpha2 Canum Venaticorum variable that fluctuates between 6.46 and 6.47 within 1.03 days ,[ 3] which corresponds to the period of the rotation. However, this has not been confirmed. HD 129899 has a relatively weak magnetic field of approximately 402± 48 gauss .[ 15]
References
^ 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 c 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 Hümmerich, Stefan; Paunzen, Ernst; Bernhard, Klaus (October 1, 2016). "New Photometrically Variable Magnetic Chemically Peculiar Stars in the ASAS-3 Archive" . The Astronomical Journal . 152 (4): 104. arXiv :1610.08253 . Bibcode :2016AJ....152..104H . doi :10.3847/0004-6256/152/4/104 . ISSN 0004-6256 . S2CID 118449879 .
^ a b c d e Kochukhov, O.; Bagnulo, S. (10 April 2006). "Evolutionary state of magnetic chemically peculiar stars" . Astronomy and Astrophysics . 450 (2): 763– 775. arXiv :astro-ph/0601461 . Bibcode :2006A&A...450..763K . doi :10.1051/0004-6361:20054596 . eISSN 1432-0746 . ISSN 0004-6361 . S2CID 18596834 .
^ a b Bidelman, W. P.; MacConnel, D. J. (October 1973). "The brighter stars of astrophysical interest in the southern sky" . The Astronomical Journal . 78 : 687. Bibcode :1973AJ.....78..687B . doi :10.1086/111475 . ISSN 0004-6256 .
^ 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 .
^ 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 c Glagolevskij, Yu. V. (January 2019). "On Properties of Main Sequence Magnetic Stars". Astrophysical Bulletin . 74 (1): 66– 79. Bibcode :2019AstBu..74...66G . doi :10.1134/S1990341319010073 . eISSN 1990-3421 . ISSN 1990-3413 . S2CID 149900274 .
^ a b Shulyak, D.; Paladini, C.; Causi, G. Li; Perraut, K.; Kochukhov, O. (July 23, 2014). "Interferometry of chemically peculiar stars: Theoretical predictions versus modern observing facilities" . Monthly Notices of the Royal Astronomical Society . 443 (2): 1629. arXiv :1406.6093 . Bibcode :2014MNRAS.443.1629S . doi :10.1093/mnras/stu1259 . S2CID 96452769 .
^ a b c d e f Netopil, Martin; Paunzen, Ernst; Hümmerich, Stefan; Bernhard, Klaus (17 March 2017). "An investigation of the rotational properties of magnetic chemically peculiar stars" . Monthly Notices of the Royal Astronomical Society . 468 (3): 2745– 2756. arXiv :1703.05218 . Bibcode :2017MNRAS.468.2745N . doi :10.1093/mnras/stx674 . eISSN 1365-2966 . ISSN 0035-8711 . S2CID 119215348 .
^ 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 .
^ 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 129899" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved September 20, 2015 .
^ 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 .
^ Bychkov, V. D.; Bychkova, L. V.; Madej, J. (April 11, 2009). "Catalogue of averaged stellar effective magnetic fields - II. Re-discussion of chemically peculiar A and B stars" . Monthly Notices of the Royal Astronomical Society . 394 (3): 1338. Bibcode :2009MNRAS.394.1338B . doi :10.1111/j.1365-2966.2008.14227.x . S2CID 120268049 .