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[vsnet-obs 1566] CVC 70

BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.70              1995, November 20
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns@innet.be                  TEL. 32-11-831504
===================================================================

NOTE FROM THE EDITOR
====================

Readers will notice that the current Circular is released with a
considerable delay, for which I apologize. I have been hospitalized 
last week, and I'm now recovering from surgery. I hope to be fully 
operational again soon, but in the meanwhile please keep submitting
your alerts and observations. I will consult my electronic mail on
a daily basis, but be advised that there will be some delay in my
replies.
   
                            
HT Cas [UGSU, 10.8v - 18.4v]
============================

The most important dwarf nova outburst of recent months is beyound any
doubt the one of HT Cas, which was detected on Nov. 17th, 1995 by
Bill Worraker, Didcot, UK (congratulations, Bill !). An extensive photo-
metric summary is presented in CVC 71 (issued simultaneously with this
Circular) and gives an overview of all observations we received. It
includes some nice visual eclipse timings by Japanese observers from the
VSOLJ.

Paul Van Cauteren, Aartselaar, Belgium informs us that he obtained some
CCD images of HT Cas during quiescense in August 1995, and found the dwarf 
nova around mag 17.4 - 17.7 (unfiltered images).

It is not obvious yet if this is a normal outburst or a superoutburst, but
last minute observations seem to indicate the variable is rapidly declining
(hence suggesting a normal outburst. Remark this would imply that more than
one decade has already passed since the last superoutburst of HT Cas in August
1985).

Daisaku Nogami and Hajime Baba of Ouda Observatory, Kyoto University, Japan
communicate : "High quality V-band CCD frames of HT Cas were obtained using
a 60-cm reflector at Ouda Station with a typical time resolution of 23s (20s 
exposure + 3s dead time).  A prelimary analysisvgives following mid-eclipse 
times (heliocentric corrections have not been applied intentionally).  
Magnitudes were determined using a V=11.88 star by Misselt (1995).

    JD (Geo)    eclipse center   outside eclipse   depth
 2450039.86757      14.45 V          13.16 V        1.29 V
      40.01482      14.45            13.17          1.28
      40.08851      14.50            13.22          1.28
      40.16218      14.57            13.26          1.31
      40.23583      14.72            13.29          1.43

Eclipses last ~12 min.  The above data seem to indicate HT Cas has already
started a rather rapid decline at a rate of ~0.5 mag/day.  However, broad 
hump features (amplitude ~0.05 mag) around JD 2450040.108 and 2450040.190 may 
be indicative of the appearance of superhumps."  

Our "Outburst Activity Data on Selected Cataclysmic Variables" shows that
HT Cas was last observed in outburst in February 1987, when it reached
magnitude 12.6 (normal outburst). Several minor brightenings have been
reported in the elapsing 8 years.


T Leo [UGSU, 10B - 15.7B]
=========================

T Leo is a dwarf nova, which recently has been added to the CVAP. We refer 
to CVC 38 for a detailed discussion on the peculiar outburst behaviour of 
this UGSU-type cataclysmic variable. Among the most remarkable phenomenon 
in its light curve, is the appearance of secondary (double) maxima.

Patrick Schmeer, Bischmisheim, Germany has informed us about his outburst 
detection of T Leo. His observation has been confirmed by C. Scovil, AAVSO 
(observation forwarded by J. Mattei) as follows :

1995 Nov 06.190 UT, [13.1  (P. Schmeer, 0.20-m SCT, seq: Huruhata);
     Nov 13.174 UT,  10.4  (P. Schmeer);
     Nov 13.204 UT,  10.4  (P. Schmeer);
     Nov 13.390 UT,  11.0  (C. Scovil);
     Nov 19.16  UT,  11.7  (L. Szentasko, 0.33-m refl.);
   
The previous outburst of T Leo was seen on May 21, 1995 by Patrick Schmeer
(CVC 38). The variable reached mag. 10.0 during this normal outburst (CVC 40).


TW Tri [UGZ, 13.3p - 17.0p]
===========================

The previous CVC issue (CVC 69) just completed the photometric summary of
the October 1995 outburst of TW Tri, and a new outburst is already announced 
on VSNET by VSOLJ member    Makoto Iida, Nagano, Japan, using an ST-6 CCD. 
Confirmation has been obtained by M. Moriyama, Sasebo, Nagasaki, Japan (VSOLJ).
 
The following estimates are available :

1995 Nov 12.454 UT,  14.2CU (M. Iida, 0.20-m refl.+ST-6, unfiltered);
     Nov 12.616 UT,  13.9:  (M. Moriyama, 0.33-cm refl.);
     Nov 13.508 UT,  14.2CU (M. Iida);
     Nov 14.884 UT,  13.7   (J. Pietz, 0.40-m refl.);
     Nov 16.472 UT,  15.2CU (M. Iida);

Although TW Tri is classified as a UGZ-type dwarf nova, no standstills have 
been observed yet in this system, as fas as we know. Therefore, it would be 
interesting to monitor this object closely.

TW Tri was last seen in outburst as recently as October 16, 1995 (CVC 63), 
by Tonny Vanmunster. Its outburst behaviour was followed in detail (CVC 65,
CVC 67 and CVC 69).


FX Cep [UGSS?, 15.0p - 17.5p]
=============================

The FX Cep outburst, reported in CVC 69, has also been observed by Jochen
Pietz, Erftstadts, Germany on Nov 12th, 1995. Follow-up observations were
also received from Gary Poyner, Birmingham, UK.

1995 Nov 12.745 UT,  15.3: (J. Pietz, 0.40-m refl.);
     Nov 12.786 UT,  14.6  (T. Vanmunster, 0.35-m refl., seq: GSC, CVC 69);
     Nov 12.800 UT,  14.6  (E. Broens, 0.35-m refl., seq: GSC, CVC 69);
     Nov 17.002 UT, [14.9  (G. Poyner, 0.40-m refl., seq: GSC);
     Nov 17.767 UT, [14.5  (G. Poyner);
    

V1113 Cyg [UGSU, 14p - <17p]
============================

Looking at both the brightness and extremely long duration of the present
outburst of V1113 Cyg (see CVC 68) it seems very likely that we finally
observed a superoutburst of this object. We regret that no hard evidence
for this statement exists, since no superhump observations were received.
We would especially like to thank Jochen Pietz for his dedicated monitoring
of the present outburst.

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
-----------------------------------------------------------------------
1995 11 02.816 [14.6  mv      Poyner, G.      40-cm refl.    VSNET
1995 11 03.853  13.5  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 04.740  13.4  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 04.774  13.4  mv KA   Vanmunster, T.  35-cm refl.    VSNET
1995 11 05.729  13.7  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 05.787  13.5  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 06.727  13.7: mv      Pietz, J.       40-cm refl.    VSNET
1995 11 06.751  13.6  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 06.821  13.5  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 06.844  13.7  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 11.721  14.1  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 12.714  14.5  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 14.818  14.7  mv      Pietz, J.       40-cm refl.    VSNET
1995 11 17.805 [15.0  mv      Poyner, G.      40-cm refl.    VSNET


V1060 Cyg [UGSS, 13.5p - 18p]
=============================

We received one additional observation of the V1060 Cyg outburst (see 
also CVC 65 and CVC 67) from Patrick Schmeer, Bischmisheim, Germany :

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
-----------------------------------------------------------------------
1995 10 22.931  13.2  mv GSC  Schmeer, P.     20-cm SCT      priv(SCH)

Tonny Vanmunster