Considered as a pair of stars, the two components are designated Gamma Tauri A (officially namedPrima Hyadum/ˌpraɪməˈhaɪədəm/, the traditional name for the system)[14] and B.
Gamma Tauri bore the traditional nameHyadum I,[12] which isLatin for "First of the Hyades". In 2016, the IAU organized aWorking Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entiremultiple systems.[17] It approved the namePrima Hyadum for the component Gamma Tauri A on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[14]
Gamma Tauri presents as aspectral class G8 or K0[2][4]giant star with anapparent magnitude of +3.65. This star has passed through themain sequence phase is now ared clump giant, meaning it is using nuclear fusion ofhelium at its core to provide energy.[3] Age estimates for Gamma Tauri range from 430 million[4] to 530 million years.[7] By comparison, the age of the Hyades cluster is about 625 million years with an error margin of 50 million years.[7]
^abJohnson, H. L.; Morgan, W. W. (1953). "Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas".Astrophysical Journal.117:313–352.Bibcode:1953ApJ...117..313J.doi:10.1086/145697.
^Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.).Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto:International Astronomical Union.Bibcode:1967IAUS...30...57E.
^abSetiawan, J.; et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch",Astronomy and Astrophysics,421:241–254,Bibcode:2004A&A...421..241S,doi:10.1051/0004-6361:20041042-1
^abBernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities".Contributi Osservatorio Astronomico di Padova in Asiago.239 (1): 1.Bibcode:1970CoAsi.239....1B.
^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].
