[vsnet-alert 9042] Re: VY Aqr outburst

[Akira Imada]

Dear Colleagues,

H. Maehara has just reported outburst of VY Aqr. 

> object         YYYYMMDD(UT)   mag      code
> AQRVY          20061007.56576 12.51B   Mhh.VSOLJ
> AQRVY          20061007.56330 12.46V   Mhh.VSOLJ

The suspected UGWZ star was investigated by Patterson et al. (1993),
who derived 0.06436 days as the mean superhump period. As can be seen
in the light curve during the 1986 May superoutburst, VY Aqr showed a 
rebrightening, which may support the WZ Sge nature of the system.

What is puzzling fact is that the system decreased superhump period as 
superoutburst proceeds (Patterson et al. 1993). This is quite peculiar
because almost all of WZ Sge stars and related objects show that superhump 
period increases. If the current outburst is a superoutburst, superhump 
period change should be studied again.

The current magnitude may indicate the variable is a rising stage. If 
this is the case, we are able to obtain the whole outburst of VY Aqr 
for the first time, which may allow us to clarify the nature of the variable.

Anyway, time revolved CCD photometry is strongly encouraged.

Best Regards,
Akira Imada
VSNET Collaboration Team