This is a large star with 2.8 times the mass of the Sun and four times the Sun's radius.[6] Thespectrum matches astellar classification of A2 V,[3] making this a seemingly typicalA-type main sequence star. However, the spectrum shows enhanced absorption lines of metals, marking this as achemically peculiarAm star.[12] The abundance of elements other than hydrogen and helium, what astronomers term the star'smetallicity, appears around 12% higher than in the Sun.[7] It is radiating 118 times the luminosity of the Sun from its outer atmosphere at aneffective temperature of 9,480 K,[6] literally giving it a white-hot glow.[13]
Theta Leonis is much younger than the Sun, with an estimated age of around 550 million years.[7] It has a moderately high rate of rotation, with aprojected rotational velocity of23 km s−1.[8] However,interferometric observations suggest that it is a rapidly rotating star being viewed nearly pole-on.[6] Measurements in the infrared band show anexcess of emission from the star and its surroundings, suggesting the presence of a circumstellar disk of dust. The temperature of this emission indicates the disk has an orbital radius of 36 AU.[7]
It bore the traditional namesChertan,Chort/ˈtʃɔːrt/[14] andCoxa/ˈkɒksə/.[15]Chertan is derived from theArabical-kharātān 'two small ribs', originally referring toDelta Leonis and Theta Leonis;Chort from Arabical-kharāt oral-khurt 'small rib', andCoxa isLatin for 'hip'. In 2016, theInternational Astronomical Union organized aWorking Group on Star Names (WGSN)[16] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[17] included a table of the first two batches of names approved by the WGSN; which includedChertan for this star.
InChinese,太微右垣 (Tài Wēi Yòu Yuán), meaningRight Wall of Supreme Palace Enclosure, refers to an asterism consisting of Theta Leonis,Beta Virginis,Sigma Leonis,Iota Leonis andDelta Leonis.[18] Consequently, theChinese name for Theta Leonis itself is太微右垣四 (Tài Wēi Zuǒ Yuán sì, English:the Fourth Star of Right Wall of Supreme Palace Enclosure.),[19] representing西次相 (Xīcìxiāng), meaningThe Second Western Minister.[20] 西次相 (Xīcìxiāng), spelledTsze Seang by R.H. Allen, means "the Second Minister of State"[21]
^abcdJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars",Communications of the Lunar and Planetary Laboratory,4 (99): 99,Bibcode:1966CoLPL...4...99J
^abCowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications",Astronomical Journal,74:375–406,Bibcode:1969AJ.....74..375C,doi:10.1086/110819
^Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions",Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg,35 (35), Astronomisches Rechen-Institut Heidelberg: 1,Bibcode:1999VeARI..35....1W
^abcdMaestro, V.; Che, X.; Huber, D.; Ireland, M. J.; Monnier, J. D.; White, T. R.; Kok, Y.; Robertson, J. G.; Schaefer, G. H.; Brummelaar, T. A. T.; Tuthill, P. G. (2013), "Optical interferometry of early-type stars with PAVO@CHARA - I. Fundamental stellar properties",Monthly Notices of the Royal Astronomical Society,434 (2): 1321,arXiv:1306.5937,Bibcode:2013MNRAS.434.1321M,doi:10.1093/mnras/stt1092,S2CID2361434
^abcdeSmith, K. C.; Dworetsky, M. M. (1993), "Elemental Abundances in Normal Late B-Stars and Hgmn-Stars from Co-Added IUE Spectra - Part One - Iron Peak Elements",Astronomy and Astrophysics,274 (2): 335,Bibcode:1993A&A...274..335S
^"The Colour of Stars",Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived fromthe original on 2013-12-03, retrieved2012-01-16
