BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.83 1996, February 26 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 =================================================================== GK Per [NA/DQ, 0.2v - 13.0V] ============================ This object is part of the TA/BAAVSS Recurrent Objects Programme, and is very likely entering a (minor?) outburst phase, as indicated by the observations below : 1996 Feb. 21.801 UT, 13.2 (G. Poyner, Birmingham, UK); Feb. 21.824 UT, 13.0 (E. Broens, Mol, Belgium); Feb. 21.904 UT, 13.3 (T. Vanmunster, Landen, Belgium); Feb. 22.510 UT, 13.2 (N. Makiguchi, Japan); Feb. 22.822 UT, 13.2 (J. Pietz, Erftstadts, Germany); Feb. 23.828 UT, 12.9 (P. Schmeer, Bischmisheim, Germany); Feb. 23.833 UT, 13.0 (K. G. Andersson, Sweden); Feb. 23.840 UT, 13.1 (M. Westlund, Sweden); Feb. 23.873 UT, 13.1 (J. Pietz); Feb. 23.881 UT, 13.1 (J. Pietz); Feb. 24.515 UT, 13.0 (M. Nakatani, Japan); Feb. 25.819 UT, 12.7 (P. Schmeer); Feb. 26.054 UT, 12.4 (J. Mc Kenna, UDA); Feb. 26.463 UT, 12.4 (Ouda Team, CCD+V filter); Feb. 26.781 UT, 12.4 (P. Schmeer); According to the "Outburst Activity Data on Selected Cataclysmic Vari- ables", GK Per underwent its previous minor outburst in July 1992, when it reached mag. 10.1. In 'Cataclysmic Variable Stars', B. Warner remarks, upon discussing the outburst characteristics of GK Per as an intermediate polar : "GK Per has a long orbital period (2d) and therefore has adequate room for a large accretion disc ... The DN outbursts of GK Per show a very slow rise (ca. 35d) to maximum ... The spectroscopic behaviour during outburst differs from ordinary DN : all lines remain strongly in emission." It is evident that multi-wavelength follow-up observations are most desirable. AQ CMi [UGSU, 14.5p - <16.5p] ============================= The AQ CMi eruption has been well-covered and resulted in some very interesting outburst data, demystifying this peculiar object a little. We have prepared a light curve of the present outburst, on the basis of all available photometric observations. You may consult it on the Cataclysmic Variables Home Page. Joe Patterson, Department of Astronomy, Columbia University reports a superhump period of 95.2+-0.2 min, based on observations with the CTIO 1-m telescope. He further adds : "Probably the dwarf nova has returned to near minimum. Continued vigilance is very desirable to see if the star "echoes" within a few days. Also, the star is so little-known that there is still no basic information about the recurrence time of normal and super-maxima, so observation over the next few months is quite important." SX LMi [NL/DQ:, 16B] ==================== We have decided to add this highly interesting cataclysmic variable to the CVAP. Observers are strongly encouraged to include the object in their observation programme, and to alert us in case of an out- burst (several professional astronomers have expressed strong interest in this variable). For the convenience of our observers, we have prepared a finder chart and sequence, which may be obtained on the Cataclsymic Variables Home Page. This is the list of outbursts of SX LMi, as they appear in the "Outburst Activity Database" : 1992.1025 48921 13.6 RoboScope, superoutburst? 1993.1211 49333 14.5 RoboScope, related to 48921 ? 1994.0114 49367 15.1 RoboScope 1994.0331 49443 13.8 RoboScope, superoutburst? 1994.1213 49699 13.4 RoboScope, superoutburst? 1995.0131 49749 14.4 RoboScope 1995.0405 49815 13.6 Pietz Remark that there has been NO outburst observation since April of last year ! The team of T. Kato, Ouda Station, Japan made photometric observations during the December 1994 outburst of SX LMi. They found a superhump period of approx. 100 min, and S. Howell, Planetary Science Institute, AZ once announced an orbital period of ca. 90 min. Tonny Vanmunster