BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.80              1996, February 06
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns@innet.be                  TEL. 32-11-831504
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         The CATACLYSMIC VARIABLES Home Page: http://www.cv.psi.edu
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LY Hya [UG:, 17.4v - 18.4v]
===========================

In response to CVC 79, Steve Howell, Planetary Science Institute, Arizona
has informed us that the suspected outburst of LY Hya is an error. There
has apparently been some confusion in the interpretation of the original
electronic message from S. Howell, for which we apologize.

Steve Howell further adds : "The orbital period of the system is 107.7 
min ... This star should be monitored for any outbursts which may occur in 
the future."

In a recent VSNET message, T. Kato, Ouda Station, Kyoto University, Japan,
added some useful background information on the object : "LY Hya was originally 
discovered as a faint blue object near the famous spiral galaxy M83.  This 
object soon turned out to be a cataclysmic variable.  Echevarria et al. 1983 
(MNRAS, 205, 559) obtained spectra which showed double peaked emission lines 
of Balmer and HeI, suggesting a high-inclination system.

Haefner et al. 1993 (Astrophys. and Space Sci. 204, 199) performed a radial
velocity study, reporting the most probable orbital period of 0.13688 day.  
Their spectra showed very strong Balmer and HeI emission lines, whose equivalent 
widths suggest a dwarf nova with a low mass-transfer rate, rather than a nova-
like system as initially thought.

More recent observations by Still et al. 1994 (MNRAS 267, 957) favored a 
solution of the system below the period gap.  All these observations suggest 
that the object has been observed in quiescence, and that we may expect dwarf 
nova outbursts."


Tonny Vanmunster