TX Leonis, also known by its Flamsteed designation49 Leonis, is a triple star system that includes an eclipsing binary, located in the constellationLeo. It was discovered to be a variable star, showing eclipses, by Ernst-Joachim Meyer in 1933.[16] The apparent 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.[3] The star's brightness drops by 0.09 and 0.03 magnitudes during the primary and secondary eclipses respectively, and neither the primary nor the secondary eclipse is total.[6]
TX Leonis is a triple star, consisting of magnitude 8.1 star (component B) separated by 2 arc seconds from the brighter eclipsing pair (components Aa and Ab).[17][18] Although orbital motion has not been detected, the companion shares a common proper motion with the primary star and is at approximately the same distance.[14]
Both stars comprising the eclipsing binary are main sequence stars. Of those two stars, star Aa has been assumed to be 8 times more luminous than star Ab,[7] although newer estimates give the luminosities as 83 L☉ and 6 L☉ respectively.[10]
^ 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.