TX Leonis, also known by itsFlamsteed designation49 Leonis, is atriple star system that includes aneclipsing binary, located in theconstellationLeo. It was discovered to be avariable star, showing eclipses, by Ernst-Joachim Meyer in 1933.[16] Theapparent magnitude of TX Leonis ranges between 5.66 and 5.75, making it faintly visible to the naked eye for an observer located well outside of urban areas.[2] The star's brightness drops by 0.09 and 0.03 magnitudes during theprimary andsecondary eclipses respectively, and neither the primary nor the secondary eclipse is total.[5]
TX Leonis is a triple star, consisting of magnitude 8.1 star (component B) separated by 2arc seconds from the brighter eclipsing pair (components Aa and Ab).[17][18] Although orbital motion has not been detected, the companion shares acommon proper motion with the primary star and is at approximately the same distance.[13]
Both stars comprising the eclipsing binary aremain sequence stars. Of those two stars, star Aa has been assumed to be 8 times more luminous than star Ab,[6] although newer estimates give the luminosities as 83 L☉ and 6 L☉ respectively.[9]
^Giuricin, G.; Mardirossian, F.; Mezzetti, M. (February 1984). "Synchronization in eclipsing binary stars".Astronomy and Astrophysics.131:152–158.Bibcode:1984A&A...131..152G.
^abcdSrivastava, J. B.; Kandpal, C. D. (January 1968). "Photoelectric elements of the eclipsing binary TX Leo".Bulletin of the Astronomical Institute of Czechoslovakia.19: 381.Bibcode:1968BAICz..19..381S.
^abcdAnders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevič, G.; Monari, G.; Cantat-Gaudin, T.; Weiler, M.; Khan, S.; Miglio, A.; Carrillo, I.; Romero-Gómez, M.; Minchev, I.; De Jong, R. S.; Antoja, T.; Ramos, P.; Steinmetz, M.; Enke, H. (2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18".Astronomy and Astrophysics.628: A94.arXiv:1904.11302.Bibcode:2019A&A...628A..94A.doi:10.1051/0004-6361/201935765.S2CID131780028.
^Mason, Brian D.; Hartkopf, William I.; Wycoff, Gary L.; Rafferty, Theodore J.; Urban, Sean E.; Flagg, Laura (December 2004). "Speckle Interferometry at the US Naval Observatory. X.".The Astronomical Journal.128 (6):3012–3018.Bibcode:2004AJ....128.3012M.doi:10.1086/425532.
