On Thu, Dec 21, 2000 at 02:33:03AM +0900, Taichi Kato wrote in [vsnet-alert 5438]: > RZ Leo: call for immediate follow-up observations! > > As reported by Rod Stubbings in [vsnet-alert 5437], the possible WZ Sge > type dwarf nova RZ Leo is undergoing an extremely rare outburst! > Despite a number of unconfirmed possible sighting reports, the last > time when the outburst of this star was observed dates back to 1987! On 1989 Mar. 10.9 UT I observed RZ Leo at mv= 13.5 - that one was probably a normal outburst (see also IAUC 4757). On 1990 Oct. 27 Gerald Dyck made a 12.8 mag estimate - apparently another normal outburst. The last recorded (likely) superoutburst occurred on 1987 Nov. 28 (cf. IAUC 4504). On the basis of the last four recorded outbursts I get a mean cycle length of 527 days. The supercycle may be 13 years! Regards, Patrick P.S.: RZ Leo is one of the top-priority objects on my program. Unfortunately I could not observe this likely SU UMa-type dwarf nova the last days due to overcast skies.