[vsnet-alert 9620] 1RXS J023238.8-371812 (?) outburst (Re: Possible nova outburst) - possible high-amplitude dwarf nova

[Taichi Kato]

> Subject: [vsnet-outburst 8139] Possible nova outburst
>
> "Pi of the Sky$B!I(B automatic trigger has detected a new object on the sky
> at (2000) RA = 02 32 38, DEC = -37 17 43. No known variable star or
> minor planet is present at this position. However, 1RXS J023238.8-371812
> X-ray source is present 29.59 '' from our object (pixel size is 36'').
>
> Time UT            magnitude
> 
> 2007-09-18 08:59:51 10.94 C
> 2007-09-19 08:48:22 11.03 C
> 2007-09-20 08:53:51 11.26 C
> 2007-09-21 08:50:16 11.22 C
>
> Best regards,
> Katarzyna Malek for "Pi of the Sky" team
> http://grb.fuw.edu.pl

   Although I don't have sufficient information, there seems to be
a good candidate for the optical counterpart of this RXS source.
According to 6dF catalog, the object g0232379-371755
(02 32 37.91, -37 17 55.3) is located close to the RXS position
and has a redshift of zero (Galactic object).  The object is in
GSC 2.2 with Bj=18.24 and R=18.15 (blue!).
All the data suggest that this object can be a cataclysmic variable
presently undergoing an outburst.  The (supposed) large outburst
amplitude would suggest an SU UMa-type or a WZ Sge-type outburst.
Accurate astrometry of the outbursting object and urgent time-series
photometry is very strongly encouraged!