BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.82 1996, February 17 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 =================================================================== FS Aur [UGZ:, 14.4v - 16.2v] ============================ Gary Poyner, Birmingham, UK reports his outburst detection of this CVAP object. Confirmation came from Tonny Vanmunster, Landen, Belgium. We have following observations available : 1996 Feb. 13.920 UT, 15.5 (G. Poyner, 0.40-m refl.); Feb. 14.926 UT, [14.9 (G. Poyner); Feb. 16.971 UT, 15.2 (T. Vanmunster, 0.35-m refl., seq: VSOLJ); According to our records, the object was last seen in outburst on 1995 December 15, when it reached mag. 14.4 (CVC 74). Given the rather frequent outbursts of this object and the relatively good coverage (even during quiescence), we have decided to drop this object from the CVAP. AQ CMi [UG:, 14.5p - <16.5p] ============================ Further to the outburst announcement in CVC 81, follow-up observations have been reported as follows : ----------------------------------------------------------------------- DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE ----------------------------------------------------------------------- 1996 02 04.962 [13.8 mv Poyner, G. CVC 81 1996 02 10.975 14.4 mv Pietz, J. CVC 81 1996 02 11.415 14.9 CU Iida, M. 20-cm refl.+ST-6 CVC 81 1996 02 12.425 15.3 CU Iida, M. 20-cm refl.+ST-6 VSNET 1996 02 12.556 14.6 CV Nogami & Ouda Team VSNET 1996 02 13.462 14.6 mv Nelson, P. VSNET 1996 02 13.895 15.3 mv Poyner, G. VSNET 1996 02 14.462 14.6 mv Nelson, P. VSNET 1996 02 14.910 15.2 mv Poyner, G. VSNET 1996 02 15.558 [14.0 mv Takahashi, S. VSNET 1996 02 15.824 15.1 CU Candela & Decomble VSNET 1996 02 16.936 [14.1 mv Vanmunster, T. VVS The detection of superhumps in AQ CMi through photoelectric photometry was first announced by Joe Patterson, Department of Astronomy, Columbia Univer- sity : "V-band photoelectric photometry by A. Shambrook with the CTIO 1 m telescope shows superhumps in the light curve of this recently-erupted dwarf nova. Timings on February 12 and 13 indicate a period of 95.9+-0.3 minutes. The amplitude (0.17 mag peak-to-trough) and waveform (fast rise, slow decline) are normal for SU UMa stars in early decline from a superoutburst. On February 13 the star was at V=14.5." Patterson further requested a close monitoring of AQ CMi for a possible "echo" signature : "CCD observers can perhaps follow this star as it gets considerably fainter, and look for the "echo" signature (after a sharp fading to near quiescence) that is often seen in this class of dwarf novae. That would be awfully interesting, as would its (certifiable) absence." The Japanese team of Ouda Station at Kyoto University independently detected superhumps in AQ CMi, and were able to derive a superhump period which is very close to the value reported by Patterson : "We observed AQ CMi for 6 hours at Ouda Station on Feb. 12, using a 60-cm refl. + CCD + Johnson V filter. Our observation independently revealed superhumps with an apmlitude of about 0.2 mag. A preliminary period analysis gives 0.06625 d (= 95.4 min) as the best estimated superhump period, which agrees with the one given by Patterson et al." Tonny Vanmunster