BELGIAN ASTRONOMICAL SOCIETY V.V.S. - Working Group Variable Stars Cataclysmic Variables Circular No.73 1995, November 25 Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM Internet: tvanmuns@innet.be TEL. 32-11-831504 =================================================================== KV And [UGSU, 14.6p - 22.5p] ============================ The KV And outburst, announced on VSNET by Tonny Vanmunster, Landen, Belgium has independently been detected by John Bortle, USA. The available observations are : 1995 Nov 23.03 UT, [15.0 (J. Bortle, seq: GSC); Nov 24.912 UT, 14.0 (T. Vanmunster, 0.35-m refl., seq: GSC); Nov 25.095 UT, 14.0 (J. Bortle); Given the brightness of the present outburst, this might very well be a superoutburst ! The previous outburst of this interesting dwarf nova, which is catalogued among Steve Howells TOADs, was seen on March 11, 1995 by John Bortle (CVC 32). In [1], Taichi Kato, Kyoto University, Japan, reports on V-band CCD photometry observations, obtained during the KV And outburst of November 1993. He describes the discovery of superhumps with a period of 0.07520 d (or its alias 0.07427 d), and an amplitude of 0.28 mag. Given the very large outburst amplitude (approx. 7.9 mags), T. Kato further argues that KV And would be a good candidate for a TOAD. It is important to closely monitor the present outburst, in order to determine the number ratio of super- and normal outbursts, and the outburst frequency. Both parameters are good indicators for discrimina- ting TOADs from other dwarf novae. References ---------- [1] Kato, T. et al., 1994, PASJ, 46, L199-L202 DM Lyr [UG, 13.6p - 18p] ======================== Further to the announcement in CVC 72, we herewith give a first photometric summary of the current DM Lyr outburst. ----------------------------------------------------------------------- DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE ----------------------------------------------------------------------- 1995 11 19.795 [14.8 mv TA Poyner, G. VSNET 1995 11 20.748 14.2 mv Pietz, J. CVC72 1995 11 21.682 14.1 mv Szentasko, L. CVC72 1995 11 21.702 14.5 mv Jensen, L. CVC72 1995 11 22.400 [14.4 mv Takahashi, S. CVC72 1995 11 22.71 14.3 mv Szentasko, L. VSNET 1995 11 22.764 14.6 mv TA Poyner, G. VSNET 1995 11 22.771 14.8 mv TA Worraker, B. priv(WOR) V493 Lyr [UG, 13.2 - 18.0p] =========================== The V493 Lyr outburst, reported in CVC 72, is rather well followed-up, as is indicated by the list of observations below. ----------------------------------------------------------------------- DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE ----------------------------------------------------------------------- 1995 11 18.757 [14.1 mv Day, J. VSNET 1995 11 20.718 14.1 mv Jensen, L. VSNET 1995 11 20.756 14.1 mv Pietz, J. CVC72 1995 11 21.681 13.9 mv Szentasko, L. CVC72 1995 11 21.701 14.0 mv Jensen, L. CVC72 1995 11 21.937 13.5 mv TA Worraker, B. CVC72 1995 11 22.7 14.0 mv Szentasko, L. VSNET 1995 11 22.765 13.7 mv Poyner, G. VSNET 1995 11 22.768 14.3 mv TA Worraker, B. priv(WOR) 1995 11 24.891 14.3: mv TA Vanmunster, T. VSNET V1113 Cyg [UGSU, 14p - <17p] ============================ Two additional observations of the previous V1113 Cyg outburst were submitted and are represented below. ----------------------------------------------------------------------- DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE ----------------------------------------------------------------------- 1995 11 12.772 14.1 mv Vanmunster, T. VSNET 1995 11 12.817 14.0 mv Broens, E. VSNET HT Cas [UGSU, 10.8v - 18.4v] ============================ The HT Cas outburst is over, and clearly has been a normal outburst. Several observers sent us detailed observing lists, which are listed in the photo- metric summary below. Taichi Kato, Kyoto University, Japan and the Ouda team members have closely monitored HT Cas during its decline and obtained some interesting data on changes in the eclipse profiles of HT Cas. In a November 23 message on VSNET, Taichi Kato says : "HT Cas seems to have stopped fading. The post-outburst object is now staying about 1 mag brighter than its "high-state" quiescence. Nightly averaged preliminary magnitudes outside eclipses are below: mid-UT mag S.D. N band ----------------------------------- 951118.618 13.27 0.075 904 V 951119.505 13.98 0.086 71 V 951120.534 15.55 0.130 91 V 951121.554 15.89 0.141 477 V 951122.494 15.93 0.210 303 V (S.D.: for a single point) The light curves on Nov. 21 and 22 show broad undulations with a time-scale of a few hours, together with short-term flickering and QPOs. Although the averaged system brightness has changed little these two nights, the shapes of eclipses have changed considerably; the system is now exhibiting rather sharp ingresses and egresses which are usually observed in quiescence." Nick James, Chelmsford, UK kindly provided us a Postscript graph showing two consecutive eclipses of HT Cas. N. James further comments : "Photometry was unfiltered using a Sony CCD and 30-cm Newtonian. The brightness of HT Cas was measured relative to the nearby GSC 4030.00719. Eclipse duration was 550 sec in each case and the times of minima were: 1995 November 19, 18:24:20 UTC (JD 2450041.26690) 1995 November 19, 20:10:30 UTC (JD 2450041.34063) These agree very well with predictions based on Kato's vsnet-alert 277 message. The sample period in the accompanying plot is approximately 25s (20s exposure + 5s read-out)." More information, including a CCD image of the field is available on the pages of The Astronomer at http://www.demon.co.uk/astronomer/htcas.html. ----------------------------------------------------------------------- DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE ----------------------------------------------------------------------- 1995 11 16.011 [15.1 mv TA Worraker, W. VSNET 1995 11 17.9049 13.4 mv TA Worraker, W. VSNET 1995 11 17.9201 13.4 mv TA Worraker, W. VSNET 1995 11 17.9417 13.3 mv TA Worraker, W. VSNET 1995 11 17.959 13.5 mv TA Hurst, G. TAEC1018 1995 11 18.733 13.2 mv AA Schmeer, P. priv(SCH) 1995 11 18.887 13.1 mv AA Jensen, L. VSNET 1995 11 19.729 [13.8 mv AA Granslo, B. H. VSNET 1995 11 19.744 13.6 mv AA Jensen, L. VSNET 1995 11 19.7549 13.9 mv TA Worraker, W. VSNET 1995 11 19.7840 14.0 mv TA Poyner, G. VSNET 1995 11 19.85 13.8 mv Verdenet, M. VSNET 1995 11 19.88 13.7 mv Verdenet, M. VSNET 1995 11 19.914 [14.7 mv TA Worraker, W. VSNET 1995 11 19.915 [15.1 mv TA Worraker, W. VSNET 1995 11 19.916 [15.1 mv TA Worraker, W. VSNET 1995 11 19.9176 15.0 mv TA Worraker, W. VSNET 1995 11 19.9190 14.2 mv TA Worraker, W. VSNET 1995 11 19.9204 14.0 mv TA Worraker, W. VSNET 1995 11 19.9226 14.1 mv TA Worraker, W. VSNET 1995 11 19.9236 14.0 mv TA Worraker, W. VSNET 1995 11 19.9246 14.1 mv TA Worraker, W. VSNET 1995 11 19.9256 14.1 mv TA Worraker, W. VSNET 1995 11 19.9272 14.2 mv TA Worraker, W. VSNET 1995 11 19.9285 14.0 mv TA Worraker, W. VSNET 1995 11 20.2465 14.4 mv TA Worraker, W. VSNET 1995 11 20.450 15.9 CU Iida, M. 20-cm+ST-6 VSNET 1995 11 20.700 [14.3 mv AA Jensen, L. VSNET 1995 11 20.779 [14.5 mv AA Pietz, J. VSNET 1995 11 21.419 16.6 CU Iida, M. 20-cm+ST-6 VSNET 1995 11 21.74 15.8 mv AA Szentasko, L. VSNET 1995 11 21.85 15.2 mv Verdenet, M. VSNET 1995 11 22.773 [15.1 mv TA Worraker, B. priv(WOR) 1995 11 22.771 [15.1 mv TA Poyner, G. VSNET 1995 11 22.466 16.4 CU Iida, M. 20-cm+ST-6 VSNET 1995 11 22.481 [14.4 mv Takahashi, S. VSNET T LEO ===== We received following additional observations of the T Leo outburst, first announced in CVC 70. It seems the present outburst has not been monitored extensively. It remains however interesting to continue observing the variable, to see if secondary maxima appear. ----------------------------------------------------------------------- DATE (UT) MAGN MS SEQ OBSERVER REMARKS SOURCE ----------------------------------------------------------------------- 1995 11 14.215 11:: mv Granslo, B. VSNET 1995 11 16.208 11:: mv Granslo, B. VSNET 1995 11 20.19 [13:: mv Granslo, B. VSNET 1995 11 21.22 [13:: mv Granslo, B. VSNET CORRECTION TO CVC 72 ==================== Lasse Jensen, Farum, Denmark has kindly informed us about an error in CVC 72. The 1995 Nov 20.718 UT observation of L. Jensen, listed at DM Lyr, should actually have been listed at V493 Lr. We apologize for any inconvenience. Tonny Vanmunster