BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.89 1996, March 27 Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM Internet: tvanmuns@innet.be TEL. 32-11-831504 -------------------------------------------------------------- The CATACLYSMIC VARIABLES Home Page: http://www.cv.psi.edu =================================================================== GO Com [UGSU, 13.1 - 20.0p] =========================== Makoto Iida, Japan reports (through VSNET) his CCD detection of an outburst of GO Com, a most interesting object which is part of the TA/BAAVSS Recurrent Objects Programme. A confirmative observation has been received from Tonny Vanmunster, Belgium. At the moment of this writing, no further details are available yet about Iida's observation. 1996 Mar 25.008 UT, [14.4 (T. Vanmunster, Belgium, 0.35-m refl.); Mar 27.135 UT, 14.7 (T. Vanmunster, seq: GSC); GO Com underwent a very remarkable series of outbursts in July/August 1995. In less than one month, 3 separate outbursts were observed. This very unusual behaviour is depicted in the GO Com light curve, available on the Cataclysmic Variables Home Page. What follows is a short review of the 1995 outburst behaviour : - The first outburst of GO Com was detected on July 16, 1995 (T. Vanmun- ster) [CVC 47]. He estimated the object at mag. 13.3. Due to the low altitute of GO Com at the moment of outburst detection, no confirmative observations were received. - Hungarian amateur Laszlo Szentasko detected the second outburst of GO Com. His observation (mag. 13.3) was made on July 30, 1995 [CVC 51]. - It is still unclear how the exact relationship between het first and second outburst of GO Com should be interpreted. Was the first outburst a normal one, triggering the second (super?)outburst ? To make things even more complicated, another outburst was reported, about two weeks later. This third one was detected by Daisaku Nogami and Taichi Kato, Ouda Team, Kyoto University, Japan on August 13, 1995 [CVC 52], when they observed GO Com at mag. 15-15.5. It was a normal one. GO Com was discovered by Kowal as an eruptive object on a Palomar plate on 1977 July 1.213. Usher independently discovered a very blue star of B=18.1 during the survey of the north galactic pole region. This star (US 31) was identical to GO Com. Vogt and Bateson classified GO Com as a WZ Sge-type dwarf nova, because of its large outburst amplitude and low outburst frequency. GO Com has an orbital period of 94.8 minutes and is included in Steve Howell's list of known TOADs. SX LMi [UGSU, 13 - 17.4V] ========================= The SX LMi outburst (see CVC 88) apparently was a very short one. The following negative estimates have been received : 1996 Mar 22.015 UT, [15.0 (T. Vanmunster, Belgium); Mar 24.872 UT, [14.2 (L. Jensen, Denmark); Mar 25.006 UT, [14.5 (T. Vanmunster); UV Per [UGSU, 11.0v - 17.5v] ============================ The UV Per outburst, announced in CVC 86, clearly has triggered the present superoutburst. We have compiled a detailed light curve, clearly showing the transition from normal towards superoutburst, on the basis of 44 photometric observations. It is presented on the Cataclysmic Variables Home Page. CVC SUBSCRIPTIONS ================= The number of subscribers to the Cataclysmic Variables Circular has continuous- ly been augmenting in recent weeks (mainly due to responses on the Cataclysmic Variables Home Page). The Circulars are now sent to 33 individuals world-wide (and a lot more are accessing them through our Web site). We are particularly pleased by the many positive reactions we receive on the contents of the CVCs. Tonny Vanmunster