BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.46 1995, July 17 Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM Internet: tvanmuns@innet.be TEL. 32-11-831504 P. Van Cauteren, de Borrekenslaan 54, 2630 Aartselaar, BELGIUM Internet: pvancaut@innet.be TEL. 32-3-8774098 =================================================================== V542 Cyg [UGSS:, 13.0p - 18.3:p] ================================ Tonny Vanmunster, Landen, Belgium reports an outburst detection of V542 Cyg, which is on the Recurrent Objects Programme of TA/BAAVSS. Confirmation has come from Eric Broens, Mol, Belgium. CVC 23 briefly discusses remarks on the classification of V542 Cyg as a dwarf nova. 1995 Jul 10.053 UT, [13.9 (T. Vanmunster, 0.35-m refl., seq: AAVSO); Jul 13.906 UT, [13.5 (T. Vanmunster, strong moonlight); Jul 14.955 UT, 13.8 (T. Vanmunster, moonlight); Jul 15.997 UT, 13.9 (T. Vanmunster); Jul 16.894 UT, 13.9 (T. Vanmunster); Jul 16.945 UT, 13.7 (E. Broens, 0.35-m refl., seq: AAVSO); V542 Cyg was last reported in outburst on December 21, 1994 by Gary Poyner, UK [CVC 23] and reached maximum brightness (mag. 13.4) the day after. The outburst lasted for more than 10 days [CVC 25]. A photometric summary, covering a much brighter outburst of V542 Cyg in June 1994, which lasted approximately 12 days, is given in CVC 9. BC UMa [UGSU, 10.9B - 18.3B] ============================ The BC UMa outburst, reported in CVC 45, apparently was a normal outburst, as communicated by Janet Mattei, AAVSO : "The following observations [completed with other ones submitted over VSNET - Ed.] indicate that the recent outburst of BC UMa has ended. This outburst was a short one, lasting a little more than 2 days. BC UMA 950702.965 UT <14.0 G. Poyner, BAA,AAVSO 950705.8 <14.0 L. Szentasko, VSNET 950706.1576 14.0 D. York, AAVSO 950706.1694 13.9 York 950706.1868 13.8 York 950706.2076 13.4 York 950706.2292 13.0 York 950706.8576 13.0 Szentasko 950707.10 12.4 G. Dyck, AAVSO 950707.1542 13.2 York 950707.1708 13.2 York 950707.2347 13.0 T. Burrows, AAVSO 950707.86 14.2 Szentasko 950708.23 <13.6 Burrows 950708.24 <13.6 Burrows 950708.25 <13.6 Burrows 950708.86 15.1 Szentasko 950708.89 <13.6 J. Gunther, AFOEV, AAVSO (via VSNET) 950710.2535 <15.5 R. Royer, AAVSO All observations were made using the AAVSO sequence." Janet Mattei further adds : "BC UMa has been closely monitored by the AAVSO since 1971. Observations in the AAVSO International Database indicate that BC UMa has had only the following four long outbursts (superoutbursts?) since 1971: May 1982, September 1990, August 1992, and April 1994, each lasting between 7 to 9 days. In addition, there are several unconfirmed, single observations, in the BC UMa data files. From the short duration of the recent well-monitored outburst, there is a possibility that some of the short outbursts may have been missed, and that the single, positive observations may be part of short outbursts." Tonny Vanmunster