θ Tauri is composed of two 3rd magnitude stars, designated Theta1 Tauri (Theta Tauri B) and Theta2 Tauri (Theta Tauri A). Theta² is brighter, hence the pair are sometimes referred to as Theta Tauri B and A, respectively. They are separated by 5.62 arcminutes (0.094°) on the sky. Based upon parallax measurements, Theta¹ Tauri is located at a distance of 152 ly (47 pc), while Theta² Tauri is at a distance of 157 light-years (48 parsecs). θ Tauri A and B are both spectroscopic binaries; the four components are designated Theta Tauri Aa (formally named Chamukuy/ˈtʃɑːmuːkuːi/), Ab, Ba, and Bb.
Nomenclatureedit
θ Tauri (Latinised to Theta Tauri) is the double star's Bayer designation;[citation needed] θ1 Tauri and θ2 Tauri those of its two constituents. The designations of the two constituents as Theta Tauri A and B, and those of the four components - Theta Tauri Aa, Ab, Ba and Bb - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[12]
In the mythology of the Maya peoples, Theta Tauri is known as Chamukuy, meaning a small bird in the Yucatec Maya language.[13] In 2016, the IAU organized a Working Group on Star Names (WGSN)[14] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[15] It approved the name Chamukuy for the component Theta Tauri Aa on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[16]
Theta Tauri A has a mean apparent magnitude of +3.40. It is classified as a Delta Scuti typevariable star and its brightness varies from magnitude +3.35 to +3.42 with a period of 1.82 hours.[20] Its primary component, Theta Tauri Aa, is a white A-typegiant. The secondary, Theta Tauri Ab, is of the 6th magnitude and is 0.005 arcseconds, or at least 2 AU, distant. It completes an orbit once every 141 days.
Theta Tauri B is the dimmer constituent. Its primary component, Theta Tauri Ba, is an orange K-typegiant with an apparent magnitude of +3.84. The secondary, Theta Tauri Bb, is of the 7th-magnitude. It has a mass of 1.31 M☉ and orbits the primary every 16.26 years on a fairly eccentric (at 0.570) orbit.[21]
Referencesedit
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^ abcdefghTorres, K. B. V.; Lampens, P.; Frémat, Y.; Hensberge, H.; Lebreton, Y.; Škoda, P.; Guenther, E.; Schwope, A.; Heber, U. (2011). "Spectra disentangling applied to the Hyades binary θ2 Tauri AB: New orbit, orbital parallax and component properties". Astronomy and Astrophysics. 525: A50. arXiv:1010.5643. Bibcode:2011A&A...525A..50T. doi:10.1051/0004-6361/201015166. S2CID 55408682.
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^ abcdefghJofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; de la Villarmois, E. Artur; Chavero, C.; Gómez, M.; Mauas, P. J. D.; Heber, U. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy and Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931.
^Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
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