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[vsnet-obs 2478] CVC 89 (GO Com, SX LMi, UV Per)

BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.89                 1996, March 27
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns@innet.be                  TEL. 32-11-831504
     --------------------------------------------------------------
         The CATACLYSMIC VARIABLES Home Page: http://vsnet.cv.psi.edu
===================================================================

GO Com [UGSU, 13.1 - 20.0p]
===========================

Makoto Iida, Japan reports (through VSNET) his CCD detection of an
outburst of GO Com, a most interesting object which is part of the 
TA/BAAVSS Recurrent Objects Programme. A confirmative observation
has been received from Tonny Vanmunster, Belgium. At the moment of
this writing, no further details are available yet about Iida's
observation.

1996 Mar  25.008 UT, [14.4  (T. Vanmunster, Belgium, 0.35-m refl.);
     Mar  27.135 UT,  14.7  (T. Vanmunster, seq: GSC);


GO Com underwent a very remarkable series of outbursts in July/August
1995. In less than one month, 3 separate outbursts were observed. This
very unusual behaviour is depicted in the GO Com light curve, available
on the Cataclysmic Variables Home Page. 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. 

GO Com has an orbital period of 94.8 minutes and is included in Steve
Howell's list of known TOADs.



SX LMi [UGSU, 13 - 17.4V]
=========================

The SX LMi outburst (see CVC 88) apparently was a very short one. The
following negative estimates have been received :

1996 Mar 22.015 UT, [15.0  (T. Vanmunster, Belgium);
     Mar 24.872 UT, [14.2  (L. Jensen, Denmark);
     Mar 25.006 UT, [14.5  (T. Vanmunster);


UV Per [UGSU, 11.0v - 17.5v]
============================

The UV Per outburst, announced in CVC 86, clearly has triggered the present
superoutburst. We have compiled a detailed light curve, clearly showing the
transition from normal towards superoutburst, on the basis of 44 photometric 
observations. It is presented on the Cataclysmic Variables Home Page.


CVC SUBSCRIPTIONS
=================

The number of subscribers to the Cataclysmic Variables Circular has continuous-
ly been augmenting in recent weeks (mainly due to responses on the Cataclysmic
Variables Home Page). The Circulars are now sent to 33 individuals world-wide
(and a lot more are accessing them through our Web site). We are particularly
pleased by the many positive reactions we receive on the contents of the CVCs.

Tonny Vanmunster