[vsnet-alert 11328] ROTSE3 J203225+602837 outburst

[Taichi Kato]

   ROTSE3 J203225+602837 outburst (the object was already reported in
ATEL #1642).  The light curve and the recurrence time (~1 year?) might
suggest a superoutburst.

===

ATEL #2126                                                           ATEL #2126

Title:          ROTSE-III discovery of a new Cataclysmic Variable
Author: J. Vinko, University of Texas; F. Yuan, University of Michigan;
                 R.  Quimby, California Institute of Technology; Z. Balog, University
                of  Arizona; D. Chamarro, M. D. Sisson, C. Akerlof, S. B. Pandey,
                University of Michigan; J. C. Wheeler and E. Chatzopoulos,  University
                of Texas, on behalf of the ROTSE collaboration
Queries:        yuanfang at umich.edu
Posted: 11 Jul 2009;  5:13  UT
Subjects:       Optical, Cataclysmic Variables, Transients, Variables

We report the discovery of a transient ROTSE3J203224.8+602837    on unfiltered
CCD images taken on Jul. 06.82 UT with the 0.45-m ROTSE-IIId    telescope
at the TUBITAK National Observatory at Bakirlitepe, Turkey, and    confirmed
by the 0.45-m ROTSE-IIIb telescope at McDonald Observatory,    Texas. The
transient was discovered by subtracting a reference image    constructed
from frames taken in 2008 (limiting mag 18.5). The brightness    of the
source was 16.05 +/- 0.1 mag (unfiltered, tied to USNO B1.0 R-mag)    
at the time of discovery. The transient was subsequently detected between
Jul. 7 and 10, declining to 16.4 +/- 0.2 mag on Jul.    10.26 UT. A finder
chart and the ROTSE light curve is posted at the    following website URL
<br />   http://rotse.net/rsvp/j203224.8+602837/j203224.8+602837.jpg <br
/>   http://rotse.net/rsvp/j203224.8+602837/rotse_lc.jpg      

At the position of the transient, R.A.=20h32m24s.76, Decl=+60o28'36".8
(equinox 2000.0), a faint stellar-like object is apparent on POSS-II
images, with USNO B1.0 magnitudes B=20.81, R=19.71 and I=18.11.  If this
is the same object, the brightening of the transient was about 4 mag
in   the R-band. There is also an ultrasoft X-ray source within 4" of this
position, listed in the Einstein IPC database, which is likely to be
associated with this object. These strongly suggest that the transient
is   a Cataclysmic Variable (CV).      

An optical spectrum obtained on Jul.09.24 UT at McDonald Obs. with the
9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph)
by   S. C. Odewahn, shows a smooth blue continuum with weak H-alpha emission.
Absorption lines due to H-beta, H-gamma and NaD are also present.  A
plot   of the spectrum can be found at the following URL <br />   http://rotse.net/rsvp/j203224.8+60
2837/het_spec_0709.jpg
<br />   The appearance of the spectrum strengthens the classification
that the   transient a CV, probably a dwarf nova in outburst.