BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.163                1998, March 10
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns@innet.be                  TEL. 32-11-831504
     CVC Web Page : http://www.astro.columbia.edu/~cba/cvc
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MM Hya [UGSU, 13.8 - 18V]
=========================

Following the outburst detection by Jonathan Kemp, CBA New York, of 
this rarely outbursting dwarf nova [VSNET-OBS 10196], various CBA 
stations have started an intensive monitoring campaign.
 
Joe Patterson, Columbia University, CBA New York, relays first 
results, based on contributions of CBA West (Dave Harvey) and CBA 
Belgium (Tonny Vanmunster) : "A 3-night baseline of observations 
yields a superhump period of 0.05862 +/- 0.00011 d (heliocentric 
correction applied). The object is fading at about 0.13 mag/d, as 
is usual for SU UMa type dwarf novae. Our earlier data verified 
Misselt and Shafter's quiescent P=0.05759 d (AJ 109, 1757), so Psh 
looks to be about 1.8+-0.2% longer than Porb."

Rudolf Novak, CBA Brno, communicates a Psh value of  0.0589 +/- 
0.0002 d, based on a 5.8h CCD photometry run, obtained on 1998, 
March 8/9, using a 0.40-m telescope and ST-7 CCD.


Tonny Vanmunster