33 Piscium
33 Piscium is a binary star system in the zodiac constellation of Pisces. It is visible to the naked eye with an apparent visual magnitude of 4.61.[2] The distance to this system, as determined from an annual parallax shift of ±0.53 mas, 25.32[1] is about 129 light years. It is moving closer to the Sun with a heliocentric radial velocity of −6.6 km/s.[4]
This system was found to have a variable radial velocity by Leah Allen and Adelaide Hobe of Lick Observatory in 1911.[10] It was identified as a single-lined spectroscopic binary, and the orbital elements were published by Canadian astronomer W. E. Harper in 1926.[3] The pair have an orbital period of 72.93 days and an eccentricity of 0.27.[6] This is a RS Canum Venaticorum variable,[3] indicating a close binary system with active star spots, and has the variable star designation BC Psc.[11]
The primary, component A, is a first-ascent red giant with a stellar classification of K0 IIIb, having chemical abundances that match a first dredge-up mixing model. Pourbaix & Boffin (2003) estimated the mass of the primary as ±0.4 M☉ and the secondary as 1.7±0.11 M☉. 0.76[3] However, Feuillet et al. (2016) derived a much lower mass estimate of ±0.22 M☉ for the primary. 0.83[7] At the age of roughly five[7] billion years, the star has expanded to 7 times the radius of the Sun.[8] It is radiating 24[8] times the Sun's luminosity from its photosphere at an effective temperature of about 4,736 K.[7]
References
- 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752 [astro-ph], Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Cite uses deprecated parameter
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(help) - 1 2 3 4 5 6 7 8 9 Ducati, J. R. (2002), "CDS/ADC Collection of Electronic Catalogues", Vizier Online Data Catalog, 2237, Bibcode:2002yCat.2237....0D.
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ignored (help) - 1 2 3 4 5 Barisevičius, G.; et al. (2011), "Chemical Composition of the RS CVn-type Star 33 Piscium", Baltic Astronomy, 20: 53−63, arXiv:1105.5650 [astro-ph.SR], Bibcode:2011BaltA..20...53B, doi:10.1515/astro-2017-0268. Cite uses deprecated parameter
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(help) - 1 2 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048 [astro-ph.SR], Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61. Cite uses deprecated parameter
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(help) - ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971 [astro-ph.GA], Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015. Cite uses deprecated parameter
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(help) - 1 2 Harper, W. E. (October 1926), "Two K-type spectroscopic binaries", Publications of the Dominion Observatory Ottawa, 3: 341−348, Bibcode:1926PDAO....3..341H.
- 1 2 3 4 Feuillet, Diane K.; et al. (2016), "Determining Ages of APOGEE Giants with Known Distances", The Astrophysical Journal, 817 (1): 15, arXiv:1511.04088 [astro-ph.GA], Bibcode:2016ApJ...817...40F, doi:10.3847/0004-637X/817/1/40, 40. Cite uses deprecated parameter
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(help) - 1 2 3 4 5 Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
- ↑ "33 Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-12.
- ↑ Campbell, William Wallace; et al. (1911), "Sixty-eight stars whose radial velocities vary", Lick Observatory Bulletin, 199: 140–154, Bibcode:1911LicOB...6..140C, doi:10.5479/ADS/bib/1911LicOB.6.140C.
- ↑ Kazarovets, E. V.; Samus, N. N. (October 1990), "The 70th Name-List of Variable Stars", Information Bulletin on Variable Stars, 3530: 1, Bibcode:1990IBVS.3530....1K.