This system became an object of interest in 1981 when V. A. Lipovetsky and J. A. Stepanian showed it to be a variable star with an ultraviolet excess. It shows strong variation from magnitude 14 down to 17, and the energy distribution at maximum resembles an OB star.[1] The system displays a cyclical light curve, for which J. W. Robertson and colleagues in 1993 found a stable period of 19.2 days.[6] The object differs from most dwarf novae by displaying short-term brightening and fading.[1]
The behavior of the system is similar to ER Ursae Majoris, showing superoutbursts and superhumps. This indicates that RZ LMi is a SU Ursae Majoris-type dwarf novae belonging to the ER UMa sub-class.[1] None of the variation can be linked to the orbital period of this binary system, and thus there is little known about the individual components. The high activity level of this object and the stability of the 19-day supercycle may indicate there is a third body in the system.[5]
References
^ abcdKato, Taichi; et al. (December 2016), "RZ Leonis Minoris bridging between ER Ursae Majoris-type dwarf nova and nova-like system", Publications of the Astronomical Society of Japan, 68 (6): 14, arXiv:1609.08791, Bibcode:2016PASJ...68..107K, doi:10.1093/pasj/psw101, 107.
^ abOlech, A.; Wisniewski, M.; Zloczewski, K.; Cook, L. M.; Mularczyk, K.; Kedzierski, P. (June 2008), "Curious Variables Experiment (CURVE). RZ LMi - the Most Active SU UMa Star", Acta Astronomica, 58: 131–152, arXiv:0806.1657, Bibcode:2008AcA....58..131O.
^Robertson, J. W.; et al. (1994), Shafter, Allen W. (ed.), "The Unusual Long-Term Repetitive Light Curve of RZ Leonis Minoris", Interacting binary stars : a symposium held in conjunction with the 105th Meeting of the Astronomical Society of the Pacific, San Diego State University, 13-15 July 1993, vol. 56, San Francisco, Calif: Astronomical Society of the Pacific, p. 298, Bibcode:1994ASPC...56..298R.
Baklanov, A. V.; Pavlenko, E. P. (December 2001), "Photometrical Study of SU UMa-type Binary RZ Lmi During the Superoutburst in 2001", Odessa Astronomical Publications, 14: 21–22, Bibcode:2001OAP....14...21B.
Thorstensen, J. R.; et al. (April 1997), "Orbital Periods for the Unusual Dwarf Novae ER Ursae Majoris and V1159 Orionis", Publications of the Astronomical Society of the Pacific, 109: 477–482, Bibcode:1997PASP..109..477T, doi:10.1086/133904, S2CID121582607.
Nogami, Daisaku; Kato, Taichi (February 1997), "Discovery of a New SU UMa Star, CI Ursae Majoris", Publications of the Astronomical Society of Japan, 49: 109–113, Bibcode:1997PASJ...49..109N, doi:10.1093/pasj/49.1.109.
Kato, Taichi; et al. (February 1996), "Large-Amplitude Superhumps in ER Ursae Majoris during the Earliest Stage of a Superoutburst", Publications of the Astronomical Society of Japan, 48: L5–L7, Bibcode:1996PASJ...48L...5K, doi:10.1093/pasj/48.1.L5.
Szkody, P.; Silber, A.; Honeycutt, R. K.; et al. (1996), Evans, A.; Wood, Janet H. (eds.), "IUE and Optical Spectra of RZ LMi and ER UMa Throughout their 19 and 43 Day Cycles", Cataclysmic variables and related objects. Astrophysics and Space Science Library; Proceedings of the 158th colloquium of the International Astronomical Union (IAU); held at Keele; United Kingdom; June 26-30; 1995, Astrophysics and Space Science Library, vol. 208, Dordrecht: Kluwer Academic Publishers, p. 55, Bibcode:1996ASSL..208...55S, doi:10.1007/978-94-009-0325-8_15, ISBN978-94-010-6632-7, S2CID197532794.
Nogami, Daisaku; et al. (December 1995), "Photometric Observations of an Extreme ER UMa Star, RZ Leonis Minoris", Publications of the Astronomical Society of Japan, 47: 897–902, Bibcode:1995PASJ...47..897N.
Osaki, Yoji (August 1995), "Why Does RZ Leonis Minoris, an Unusual SU UMa Star, Have Such a Short Supercycle?", Publications of the Astronomical Society of Japan, 47: L25–L29, Bibcode:1995PASJ...47L..25O.
Robertson, J. W.; et al. (May 1995), "RZ Leonis Minoris, PG 0943+521, and V1159 Orionis: Three Cataclysmic Variables with Similar and Unusual Outburst Behavior", Publications of the Astronomical Society of the Pacific, 107: 443, Bibcode:1995PASP..107..443R, doi:10.1086/133572.
Pikalova, O. D.; Shugarov, S. Yu. (1995), Bianchini, A.; et al. (eds.), "The Photometric Investigation of RZ LMi", Cataclysmic Variables, Proceedings of the conference held in Abano Terme, Italy, 20-24 June 1994, Astrophysics and Space Science Library, vol. 205, Dordrecht: Kluwer Academic Publishers, p. 173, Bibcode:1995ASSL..205..173P, doi:10.1007/978-94-011-0335-0_55, ISBN0792336763.