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[vsnet-obs 742] CVC 45 (BC UMa)



BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.45                  1995, July 10
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
===================================================================

BC UMa [UGSU, 10.9B - 18.3B]
============================

We have been informed by J. Mattei, AAVSO that D. York, Abiquiu, NM
has discovered a rare outburst of the UGSU-type dwarf nova BC UMa.
Available observations, taken from AAVSO Alert Notice 210, are :

1995 Jul 06.158 UT,  14.0 (D. York, 0.45-m refl., seq: AAVSO);
     Jul 07.235 UT,  13.0 (D. York);

Taichi Kato, Kyoto University, Japan communicates : "BC UMa was first
identified as a definite SU UMa-type dwarf nova by M. Iida on 1994,
April 28, when he discovered superhumps with a period of 0.0619 day.
Subsequent confirmation was made by C. Kunjaya on 1994, May 2, when 
the superhump period was determined as 0.0629 day."

Steve Howell, Planetary Science Institute, Astrophysics Group, AZ
further adds : "The orbital period of BC UMa was first determined
in PASP, 1990, 102, 758. That period was 91.2 +/- 2 min. It will be
interesting to see if a superhump period agrees with this period.
BC UMa is a TOAD (Howell et al, 1995, ApJ, 439, 337) with an outburst
amplitude of >7 mags, reaching maximum near 10.9 in V."

According to our records in the Outburst Activity Database, BC UMa was 
last discovered in outburst on 1994, April 28, by M. Iida. During that
superoutburst, it reached mag. 12.4 and remained brighter than V=15
for 9 days.

Observers are strongly encouraged to report the used sequences and
comparison stars when submitting observations of BC UMa.


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

The outburst of V1113 Cyg, announced in CVC 44, clearly was a normal
outburst, given its short duration. The photometric summary below 
contains all observations that we received. It's interesting to compare
this summary with the one presented in CVC 36, which contains details of
a superoutburst that lasted for more than 10 days.

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
------------------------------------------------------------------------
1995 06 21.913 [14.2  mv VS   Vanmunster, T.  35-cm refl.    CVC 44
1995 06 21.982 [14.3  mv VS   Poyner, G.      40-cm refl.    VSNET
1995 06 23.947 [13.6  mv      Jensen, L.      33-cm refl.    priv(JEN)
1995 06 24.938 [13.6  mv      Jensen, L.      33-cm refl.    priv(JEN)
1995 06 24.965  13.9  mv VS   Vanmunster, T.  35-cm refl.    CVC 44
1995 06 24.972  13.9  mv VS   Broens, E.      35-cm refl.    CVC 44
1995 06 25.932  14.8  mv VS   Vanmunster, T.  35-cm refl.    VVS
1995 06 25.938  14.7  mv      Pietz, J.       40-cm refl.    VSNET
1995 06 25.942 [13.6  mv      Jensen, L.                     priv(JEN)
1995 06 25.951  14.2  mv VS   Poyner, G.      40-cm refl.    VSNET
1995 06 26.985 [14.6  mv VS   Vanmunster, T.  35-cm refl.    VVS
1995 06 27.006 [15.5  mv      Pietz, J.       40-cm refl.    VSNET
1995 06 27.062 [14.0  mv      Schmeer, P.     20-cm SCT      priv(SCH)
1995 06 27.942 [14.6  mv VS   Vanmunster, T.  35-cm refl.    VVS


DX And [UG, 10.9p - 16.4p]
==========================

Following the outburst announcement of DX And in CVC 42, we have been
informed by the AAVSO (AAVSO Alert Notice 209) of an independent detection 
by their member Jack Nordby, Moorhead, MN. Since an outburst of DX And
generally lasts two to three weeks, it may be that the start of the 
present outburst has been missed. Available observations are listed in
the table below.

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
------------------------------------------------------------------------
1995 06 08.990 [13.8  mv AA   Vanmunster, T.  35-cm refl.    CVC 42
1995 06 10.010 [13.4  mv AA   Schmeer, P.     20-cm SCT.     CVC 42  
1995 06 18.351  12.1  mv AA   Nordby, J.                     AN 209
1995 06 18.993  12.2  mv AA   Vanmunster, T.  35-cm refl.    CVC 42
1995 06 19.001  12.3  mv TA   Poyner, G.      22-cm refl.    CVC 42
1995 06 19.009  12.3  mv AA   Broens, E.      35-cm refl.    CVC 42
1995 06 19.939  12.6  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 19.974  13.2  mv AA   Diepvens, A.    15-cm refr.    VVS
1995 06 19.996  12.3  mv AA   Schmeer, P.     20-cm SCT      priv(SCH)
1995 06 20.007  12.3  mv      Pietz, J.       20-cm SCT      priv(PIE)
1995 06 20.284  12.3  mv AA   Nordby, J.                     AN 209
1995 06 20.461  12.5  mv AA   Royer, R.                      AN 209
1995 06 21.26   12.9  mv AA   Dyck, G.                       AN 209
1995 06 21.949  12.7  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 21.972  12.8  mv AA   Jensen, L.      33-cm refl.    priv(JEN)
1995 06 21.978  12.9  mv TA   Poyner, G.      40-cm refl.    VSNET
1995 06 22.003  13.1  mv      Pietz, J.       20-cm SCT      priv(PIE)
1995 06 22.019  12.9  mv AA   Diepvens, A.    15-cm refr.    VVS
1995 06 22.967  13.6  mv AA   Schmeer, P.     20-cm SCT      priv(SCH)
1995 06 23.958 [13.0  mv AA   Jensen, L.      33-cm refl.    priv(JEN)
1995 06 23.993 [13.8  mv AA   Diepvens, A.    15-cm refr.    VVS
1995 06 24.970 [13.0  mv AA   Jensen, L.      33-cm refl.    priv(JEN)
1995 06 24.987  13.7  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 25.951  14.1  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 25.974 [13.0  mv AA   Jensen, L.      33-cm refl.    priv(JEN)
1995 06 26.018  14.0: mv      Pietz, J.       40-cm refl.    VSNET
1995 06 26.949 [13.8  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 27.026 [14.2  mv AA   Schmeer, P.     20-cm SCT      priv(SCH)
1995 06 27.027  14.4  mv      Pietz, J.       40-cm refl.    VSNET
1995 06 27.960 [13.8  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 28.027  14.4  mv      Pietz, J.       40-cm refl.    VSNET
1995 06 29.001  14.1  mv AA   Vanmunster, T.  35-cm refl.    VVS
1995 06 29.022  14.4  mv      Pietz, J.       40-cm refl.    VSNET
1995 06 29.069  14.6  mv TA   Poyner, G.      40-cm refl.    VSNET
1995 06 29.956 [14.2  mv AA   Vanmunster, T.  35-cm refl.    VVS


IP Peg [UG, 12.0B - 16.6B]
==========================

The IP Peg outburst apparently was a short-lived one, unless most of the
start of the outburst has been missed (bad weather and moon-light). No
eclipse timings have been received. The summary below concludes our
monitoring of the current outburst.

-----------------------------------------------------------------------
DATE (UT)       MAGN  MS SEQ  OBSERVER        REMARKS        SOURCE
------------------------------------------------------------------------
1995 06 08.994 [12.9  mv TA   Vanmunster, T.  35-cm refl.    CVC 43
1995 06 19.014  13.0  mv TA   Vanmunster, T.  35-cm refl.    CVC 43
1995 06 19.965  13.7  mv TA   Vanmunster, T.  35-cm refl.    CVC 43
1995 06 20.007  13.9  mv TA   Vanmunster, T.  35-cm refl.    CVC 43
1995 06 20.029  13.8  mv      Pietz, J.       40-cm refl.    priv(PIE)
1995 06 20.455  13.8  mv      Royer, R.                      AN 209
1995 06 21.975 [13.8  mv TA   Vanmunster, T.  35-cm refl.    VVS   
1995 06 22.019 [13.8  mv TA   Diepvens, A.    15-cm refr.    VVS
1995 06 24.992 [13.8  mv TA   Vanmunster, T.  35-cm refl.    VVS    

Tonny Vanmunster