BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.128 1997, February 07 Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM Internet: tvanmuns@innet.be TEL. 32-11-831504 CBA Belgium Web Page : http://www.astro.columbia.edu/~cba/be =================================================================== GO Com [UGSU, 13.1 - 20.0p] =========================== We have been informed by Patrick Schmeer, Germany of an outburst of GO Com, an object which is part of the TA/BAAVSS Recurrent Objects Programme. Confirmative observations were received from the AAVSO [News Flash No. 111]. 1997 Feb 06.11 UT, [14.2 (P. Schmeer, 0.20-m SCT); Feb 07.111 UT, 14.0: (Schmeer); Feb 07.194 UT, 13.7 (Schmeer); Feb 07.212 UT, 13.8 (Stewart); Feb 07.317 UT, 14.15 (Zissell, CCD + V filter); Feb 07.378 UT, 14.15 (Zissell, CCD + V filter); The previous outburst of GO Com was reported on 1996, Mar 26 by M. Iida, Japan [CVC 89], and was a faint, normal one [CVC 90]. GO Com underwent a very remarkable series of outbursts in July/August 1995. In less than one month, 3 separate outbursts were observed. 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. Var21 CrB [UG, 14.5 - <17.5p] ============================= Lasse Jensen, CBA Denmark, has observed an outburst of Var21 CrB, an object on the Belgian CVAP. His CCD observations are reported below. 1997 Jan 28.2 UT, 15.5 (L. Jensen, 0.25-m SCT, unfiltered CCD); Feb 01.202 UT, 16.3 (Jensen); Feb 02.200 UT, <17.2 (Jensen); Var21 CrB was last seen in outburst on August 13, 1996 by John Day, UK [CVC 104]. The outburst lasted for approx. 13 days, but failed to reveal any superhumps, despite CCD coverage [CVC 107]. IP Peg [UGSS+E, 12.0B - 16.6B] ============================== We have been informed (through VSNET) by Jochen Pietz, Germany of an outburst of IP Peg. This object is part of the TA/BAAVSS Recurrent Objects Programme. Confirmative observations were received from the AAVSO [News Flash No. 111]. The object currently is very unfavourable located in evening twilight. 1997 Feb 06.092 UT, <13.8 (G. Hanson, USA); Feb 06.75 UT, 13.7 (J. Pietz, Germany); Feb 06.9778 UT, 13.6: (G. Chaple, USA); Feb 06.99 UT, 12.4 (G. Dyck, USA); The last confirmed outburst of IP Peg was reported by T. Kato, Japan on Sep 17, 1996 [CVC 110], EG Cnc [UGWZ, 11.9v - 17:v] =========================== It looks as if this cataclysmic variable has finally returned to quiescence, although intensive monitoring remains important. Below, we present another photometric summary with recent observations. ------------------------------------------- DATE (UT) MAGN MS OBSERVER ------------------------------------------- 1997 01 27.512 14.76 CV Koshiro 1997 01 27.566 14.5 mv Itoh 1997 01 27.860 14.9: mv Broens 1997 01 27.980 14.9 CU Vanmunster 1997 01 28.112 <14.1 mv Hanson 1997 01 28.168 15.4 CU Vanmunster 1997 01 28.851 <14.6 mv Poyner 1997 01 29.571 <14.8 mv Itoh 1997 01 30.257 <14.6 mv Hanson 1997 01 30.540 <14.0 mv Makiguchi 1997 01 30.98 <15.6 mv Kinnunen 1997 01 31.278 <14.6 mv Hanson 1997 01 31.7298 <16.5 CU Jensen 1997 01 31.749 <13.9 mv Watanabe 1997 01 31.816 <16.18 CV Koshiro 1997 01 31.86 <15.1 mv Kinnunen 1997 02 01.088 <15.8 mv Modic 1997 02 01.233 <14.6 mv Hanson 1997 02 01.571 <14.2 mv Itoh 1997 02 01.644 <14.1 mv Watanabe 1997 02 01.667 16.99 CV Ouda 1997 02 01.7270 <16.5 CU Jensen 1997 02 01.92 <15.6 mv Kinnunen 1997 02 02.341 <14.1 mv Hanson 1997 02 02.938 <15.1 mv Poyner 1997 02 03.494 <14.1 mv Hanson 1997 02 03.581 <14.8 mv Itoh 1997 02 03.603 <14.6 mv Watanabe 1997 02 03.660 <14.6 mv Watanabe 1997 02 04.144 <14.1 mv Hanson 1997 02 04.464 <13.9 mv Watanabe 1997 02 04.573 <16.28 CV Koshiro 1997 02 05.78 <14.7 mv Kinnunen 1997 02 06.136 <14.1 mv Hanson 1997 02 06.587 <14.0 mv Makiguchi 1997 02 06.84 <15.1 mv Kinnunen EY Cyg [UGSS, 11.4v - 15.5v] ============================ The EY Cyg outburst, first announced in CVC 125, apparently is over, as one can deduce from the observations below. ------------------------------------------- DATE (UT) MAGN MS OBSERVER ------------------------------------------- 1997 01 28.743 <12.7 mv Schmeer 1997 01 31.853 <13.6 mv Watanabe 1997 01 31.66 <13.5 mv Kinnunen EDITORIAL ABSENCE ----------------- Please note that the Editor will be absent between February 23 and March 2, 1997. Tonny Vanmunster