BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.160 1998, January 26 Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM Internet: tvanmuns@innet.be TEL. 32-11-831504 CVC Web Page : http://www.astro.columbia.edu/~cba/cvc =================================================================== VW CrB [UGSU, 14.5 - <17.5p] ============================ Tonny Vanmunster, CBA Belgium Observatory, reports his detection by CCD of an outburst of VW CrB (alias Var21 CrB), using a 0.25-m telescope and ST-7 CCD camera (unfiltered exposure). Observation : 1998 Jan 26.132 UT, 15.8 (T. Vanmunster, 0.25-m SCT, unfilt. exp.); Apparently, the object has not been observed in recent weeks [VSNET reports], so it is difficult to judge in which state of the outburst the system is residing. Follow-up observations therefore are encouraged. During the May 1997 outburst of VW CrB, superoutbursts were indepen- dently detected by Rudolf Novak, Nicholas Copernicus Observatory, Brno, Czech Republic and by the undersigned [CVC 139]. A superhump period of 0.0743 +/- 0.0006 days was subsequently derived by D. Nogami et al., Kyoto University, Japan. T Leo [UGSU, 10B - 15.7B] ========================= Gene Hanson, Arizona reports his visual detection of an outburst of this SU UMa-type dwarf nova. Confirmation has been received from Gary Poyner, UK. Observations : 1998 Jan 25.088 UT, [15.3 (G. Poyner, visual); Jan 25.460 UT, 13.9 (G. Hanson, visual); Jan 26.105 UT, 10.4 (G. Poyner); Jan 26.404 UT, 10.7 (G. Hanson); T Leo was last seen in outburst in October 1997 by P. Schmeer. This was a normal outburst (only 2 positive observations). T Leo is a remarkable object, in the sense that on a couple of occasions, it has shown rebrightenings after outbursts (maybe of a similar nature as the ones exhibited by GO Com, V1028 Cyg and others). These secondary maxima of T Leo can be almost as bright as the primary outburst, but last for only one day or so. Since there is considerable interest in a detailed study of this phenomenon, T Leo has been added to the CVAP programme in May 1995. Our primary objective was to monitor a number of future outbursts intensively in order to detect and follow-up these secondary maxima. We encourage our observers to continue monitoring this object during its present outburst in the period after the initial decline. Tonny Vanmunster