Light curves for GQ Leonis. The upper panel shows the short term variability as seen byTESS,[15] and the lower panel shows the brightness over a much longer time interval as seen byASASSN.[16]
In 2001, the star was reported to show low-amplitudephotometric variations with a period of 4.45 days. It was suspected that the star was aBY Draconis variable due to the period paired with the X-ray and EUV emissions.[11] This was confirmed in 2004 in a paper which also newly classifiedHD 77191 andV573 Puppis as BY Dra variables.[14] The star received itsvariable-star designation GQ Leonis in 2003.[17]
Slow fluctuations are known to occur in the star's radial velocity. In a 2019 study, a 572-day (1.57 a) period was mentioned to fit the observed variations, but other periods remain possible. This object is also avisual binary, designated MET 57Aa/Ab in theWashington Double Star Catalog, with a separation of 0.25arcseconds and a period of roughly 45 years. Additionally, anoptical component (MET 57B) exists 9.5 arcseconds away.[8]
^abCutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)".CDS/ADC Collection of Electronic Catalogues.2246: II/246.Bibcode:2003yCat.2246....0C.
^Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1".Astronomy Reports.61 (1): 80.Bibcode:2017ARep...61...80S.doi:10.1134/S1063772917010085.
^Kazarovets, E. V.; Kireeva, N. N.; Samus, N. N.; Durlevich, O. V. (27 May 2003). "The 77th Name-List of Variable Stars".Information Bulletin on Variable Stars.5422:1–56.Bibcode:2003IBVS.5422....1K.
