[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

[vsnet-obs 939] CVC 52



BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.52                1995, August 15
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns@innet.be                  TEL. 32-11-831504
     P. Van Cauteren, de Borrekenslaan 54, 2630 Aartselaar, BELGIUM
     Internet: pvancaut@innet.be                  TEL. 32-3-8774098
===================================================================

GO Com [UGWZ:, 13.1p - 20p]
===========================

Daisaku Nogami and Taichi Kato, Ouda Team, Kyoto University, Japan report
another outburst (or brightening) of this most intriguing object: "The
current magnitude estimated from CCD images is 15-15.5 on Aug. 13.44 UT."

This is the third reported outburst of GO Com in less than one month. As 
far as we understand, this behaviour has never been observed before in 
any cataclysmic variable. One may wonder what the physical processes are 
that are at the basis of this most uncommon behaviour.

Taichi Kato and the Ouda Team also comment on the possible existence of 
superhumps in their observations : "The rate of decline of GO Com (~0.1 
mag/day) seems to be characteristic to a superoutburst.  Although very 
preliminary, Aug. 3 data seem to suggest the existence of variations of
~0.1 mag. A broad maximum possibly occurred around Aug. 3.473 UT (super-
hump?), but is not conclusive because of the short duration (~40min) of 
the observing run and the bright sky background."

The photometric summary below lists all observations of GO Com that we
received, covering the three reported outbursts !

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
-----------------------------------------------------------------------
1995 07 16.951  13.3  mv GSC  Vanmunster, T.  35-cm refl.    CVC 47
1995 07 18.509 [13.6  mv      Moriyama, M.    33-cm refl.    VSNET
1995 07 18.908 [13.5  mv      Schmeer, P.     20-cm SCT      priv(SCH)
1995 07 19.917 [13.4  mv      Schmeer, P.     20-cm SCT      priv(SCH)
1995 07 19.928 [13.5  mv GSC  Vanmunster, T.  35-cm refl.    CVC 47
1995 07 20.921 [13.5  mv GSC  Vanmunster, T.  35-cm refl.    CVC 47
1995 07 21.87  [15.2  mv GSC  Fidrich, R.     45-cm refl.    priv(FID)
1995 07 21.87  [15.2  mv GSC  Bakos, G.       45-cm refl.    priv(FID)
1995 07 22.88  [15.2  mv GSC  Fidrich, R.     45-cm refl.    priv(FID)
1995 07 22.88  [15.2  mv GSC  Bakos, G.       45-cm refl.    priv(FID)
1995 07 22.923 [14.4  mv GSC  Vanmunster, T.  35-cm refl.    VVS
1995 07 25.481 [15.0  CU      Iida, M.        16-cm+ST-6     VSNET
1995 07 25.483  16.6  CV      Kato, T.        60-cm+ST-6     VSNET
1995 07 27.840 [14.4  mv GSC  Fidrich, R.     45-cm refl.    VSNET
1995 07 27.910 [14.4  mv GSC  Szabo, R.       45-cm refl.    VSNET
1995 07 30.845  13.3  mv GSC  Szentasko, L.   33-cm refl.    VSNET
1995 07 31.445  13.6  CV GSC  Kato, T.        60-cm refl.    VSNET
1995 07 31.8    13.2  mv GSC *Szentasko, L.   33-cm refl.    VSNET
1995 08 01.447  13.5  CV GSC  Kato, T.        60-cm refl.    VSNET
1995 08 01.8    13.4: mv GSC *Szentasko, L.   33-cm refl.    VSNET
1995 08 01.895  13.4  mv GSC  Vanmunster, T.  35-cm refl.    VVS    
1995 08 02.8    13.5  mv GSC *Szentasko, L.   33-cm refl.    VSNET
1995 08 03.467  13.8  CV GSC *Kato, T.        60-cm refl.    VSNET
1995 08 03.8    13.9  mv GSC *Szentasko, L.   33-cm refl.    VSNET
1995 08 04.459  13.9  CV GSC *Kato, T.        60-cm refl.    VSNET
1995 08 04.8   [13.2  mv GSC *Szentasko, L.   33-cm refl.    VSNET
1995 08 05.457  14.3  CV GSC *Kato, T.        60-cm refl.    VSNET
1995 08 05.465  13.8  CU GSC *Iida, M.        16-cm+ST-6     VSNET
1995 08 06.457  15.1  CV GSC *Kato, T.        60-cm refl.    VSNET
1995 08 07.452  16.5  CV GSC *Kato, T.        60-cm refl.    VSNET
1995 08 13.44   15:   CV GSC *Kato, T.        60-cm refl.    VSNET



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

Ronald Downes, Space Telescope Science Institute, Maryland, emails :
"In regard to CVC 50 on TW Tri, I can provide some more information.  
First, the classification as a Z Cam is not secure, although the CV 
classification does seem to be.  There is a published spectrum by 
Zwitter and Munari in A. & A. Suppl. 107, 503, 1994, which shows strong 
Balmer emission. As for the coordinates, I have remeasured TW Tri, and 
get the following offsets from the published position: RA = 0.05s W, 
Dec = 0.9" N."

Taichi Kato, Ouda Observatory, Kyoto University, Japan communicates :
"TW Tri was discovered by Kurochkin (Astron. Trisk. No. 1023 (1978), 
TW Tri = SVS 2288).  The author gave a finding chart and list of observa-
tions. He commented that a typical outburst cycle length is 28 days.  
I could not find documentation about the existence of standstills. This 
object has been included in the targets of VSOLJ (Variable Star Observers 
League Japan) probably since 1987.  A number of outbursts have been 
reported, including more recent one(s) reported on VSNET (last year?)."

Taichi Kato and his team members finally also found outburst images of 
TW Tri,dating from July 27, 1995, when the outburst apparently had not 
yet fully developed.

The photometric summary below lists some additional observations of the
present outburst. Unfortunately, the declining phase has not been covered
very well (due to interference from the full moon).

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
-----------------------------------------------------------------------
1995 08 05.066  13.8  mv GSC *Vanmunster, T.  35-cm refl.    VVS
1995 08 06.045  13.8  mv GSC *Vanmunster, T.  35-cm refl.    VVS   
1995 08 06.079  13.7  mv GSC *Broens, E.      35-cm refl.    priv(BRO)



V1028 Cyg [UGSS, 13.0p - 18p]
=============================

Hajime Baba and Taichi Kato, Ouda team, Kyoto University, Japan,
communicate: "Our CCD observations of Aug. 9 show that the superhumps of 
V1028 Cyg seem to have grown up again. The lightcurve of this object shows
an amplitude on Aug. 9 of about 0.15 mag. in V band, although it was less
than 0.05 mag. on Aug. 8. We have never encountered such a curious beha-
viour before. We are interested in the physical process that happens in 
this system, which we will follow from now on."

Additional observations of the present outburst (see also CVC 51) :

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
-----------------------------------------------------------------------
1995 07 30.9    13.0  mv AA  *Szentasko, L.   33-cm refl.    VSNET
1995 08 01.9    13.0  mv AA  *Szentasko, L.   33-cm refl.    VSNET
1995 08 01.906  12.9  mv KA  *Pietz, J.       40-cm refl.    VSNET
1995 08 01.926  12.9  mv AA  *Diepvens, A.    15-cm refr.    VVS
1995 08 02.891  12.7  mv AA  *Diepvens, A.    15-cm refr.    VVS
1995 08 02.899  13.3  mv KA  *Pietz, J.       40-cm refl.    VSNET
1995 08 02.9    13.5  mv AA  *Szentasko, L.   33-cm refl.    VSNET
1995 08 02.903  12.7  mv GSC *Broens, E.      35-cm refl.    priv(BRO)
1995 08 03.014  13.2  mv     *Poyner, G.      40-cm refl.    VSNET
1995 08 03.240  13.1: mv AA  *Dillon, W.      28-cm SCT      VSNET
1995 08 03.9    13.9  mv AA  *Szentasko, L.   33-cm refl.    VSNET
1995 08 04.876  13.6  mv KA  *Pietz, J.       40-cm refl.    VSNET
1995 08 04.890  13.0  mv AA  *Diepvens, A.    15-cm refr.    VVS
1995 08 04.9    13.8  mv AA  *Szentasko, L.   33-cm refl.    VSNET
1995 08 04.903  13.7  mv     *Poyner, G.      40-cm refl.    VSNET
1995 08 04.970  12.9  mv GSC *Broens, E.      35-cm refl.    priv(BRO)
1995 08 05.050  13.6  mv AA  *Vanmunster, T.  35-cm refl.    VVS
1995 08 05.057  13.5  mv KA  *Pietz, J.       40-cm refl.    VSNET
1995 08 05.058  13.9  mv AA  *Biesmans, M.    28-cm SCT      priv(BIE)
1995 08 05.874  14.0  mv KA  *Pietz, J.       40-cm refl.    VSNET
1995 08 05.9    13.5  mv AA  *Szentasko, L.   33-cm refl.    VSNET
1995 08 05.910  13.8  mv     *Poyner, G.      40-cm refl.    VSNET
1995 08 05.956  13.9  mv AA  *Diepvens, A.    15-cm refr.    VVS
1995 08 05.984  13.9  mv KA  *Pietz, J.       40-cm refl.    VSNET
1995 08 06.028  13.7  mv AA  *Vanmunster, T.  35-cm refl.    VVS
1995 08 06.034  13.6  mv GSC *Broens, E.      35-cm refl.    priv(BRO)
1995 08 07.537  15.1  CU     *Iida, M.        16-cm+ST-6     VSNET
1995 08 08.906  14.1  mv     *Poyner, G.      40-cm refl.    VSNET 
1995 08 10.997 [14.0  mv GSC *Poyner, G.      40-cm refl.    VSNET



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

The outburst of FX Cep has been very well monitored by several observers,
yielding a detailed lightcurve. The photometric summary below (complemen-
tary to the one published in CVC 51) concludes the observations of the 
present outburst.

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
-----------------------------------------------------------------------
1995 08 01.952  14.6  mv GSC *Broens, E.      35-cm refl.    priv(BRO)  
1995 08 02.010  14.8  mv KA  *Biesmans, M.    28-cm SCT      priv(BIE)
1995 08 02.927  14.8  mv GSC *Poyner, G.      40-cm refl.    VSNET
1995 08 02.934  14.7  mv GSC *Broens, E.      35-cm refl.    priv(BRO)
1995 08 02.988  15.0  mv     *Pietz, J.       40-cm refl.    VSNET
1995 08 03.032  14.8  mv KA  *Biesmans, M.    28-cm SCT      priv(BIE)
1995 08 04.051  15.1: mv KA  *Biesmans, M.    28-cm SCT      priv(BIE)
1995 08 04.916 [15.0: mv     *Pietz, J.       40-cm refl.    VSNET
1995 08 04.963  14.9  mv GSC *Poyner, G.      40-cm refl.    VSNET
1995 08 05.007  15.2  mv KA  *Biesmans, M.    28-cm SCT      priv(BIE)
1995 08 05.022  14.7  mv GSC *Broens, E.      35-cm refl.    priv(BRO)
1995 08 05.097  14.9  mv GSC *Vanmunster, T.  35-cm refl.    VVS  
1995 08 05.934  15.0  mv GSC *Poyner, G.      40-cm refl.    VSNET
1995 08 06.069  15.2: mv GSC *Vanmunster, T.  35-cm refl.    VVS  
1995 08 06.085 [14.6  mv GSC *Broens, E.      35-cm refl.    priv(BRO)
1995 08 08.942 [14.5  mv GSC *Poyner, G.      40-cm refl.    VSNET
1995 08 10.972 [14.5  mv GSC *Poyner, G.      40-cm refl.    VSNET

Tonny Vanmunster