[vsnet-alert 11638] (fwd) ATEL: 1RXS J231935.0+364705 outburst

[Taichi Kato]

The Astronomer's Telegram                   http://www.astronomerstelegram.org 
==============================================================================
ATEL #2282                                                           ATEL #2282

Title:          Outburst of Cataclysmic Variable 1RXS J231935.0+364705
Author: D.V. Denisenko (IKI, Moscow)
Queries:        denis at hea.iki.rssi.ru
Posted: 5 Nov 2009;  14:53  UT
Subjects:       Optical, X-ray, Request for Observations, Cataclysmic Variables



We report the first real-time detection of the outburst (from 19.0 mag
to 14.5 mag on Nov. 5, 2009) of an optical counterpart of the poorly studied
ROSAT X-ray source 1RXS J231935.0+364705 in Andromeda. Earlier (in 2007)
we identified it with the NSVS variable object 9022680 (see http://hea.iki.rssi.ru/~denis/NSVS9022680.gif
). NSVS 9022680 showed a dwarf nova-like outburst in November 1999. Due
to the poor angular resolution of ROTSE-I (14") this object is actually
a blend of two stars separated by 18.5". The fainter (north-western) star
is showing outbursts. The name and coordinates of the new cataclysmic variable
are: USNO-B1.0 1267-0564384 RA=23h19m36.06s, +36o47'00.3" (J2000.0).  

The color-combined (BRIR) 10'x9' DSS finder chart of RX J2319.6+3647 is
available at http://hea.iki.rssi.ru/~denis/J2319+3647-comps.gif (position
of the variable object is marked with dashes). Another outburst was recorded
on the POSS-II infrared plate taken on 1995 Aug. 28. This is why the variable
has peculiar colors in USNO-B1.0 catalogue (B1-R1=0.0, R1-R2=0.0, R2-I=4.0):
B1=17.73 R1=17.73 B2=18.66 R2=17.73 I=13.63.      

The new variable was monitored with the Bradford Robotic Telescope since
October 2009.  The following photometry has been obtained:      Time (JD)
YYYY-MM-DD.ddd  R mag 
---------------------------------- 
2455121.542  2009 10 17.042  18.74 
2455127.552  2009 10 23.052  18.96 
2455140.522  2009 11 05.022  14.48 

The outburst amplitude (about 4.5 mag) and duration of the 1999 outburst
in ROTSE data suggest that the new variable is a dwarf nova of the SU UMa
(UGSU) subtype. Follow-up photometric observations are requested to determine
the orbital period and to search for possible superhumps. Checking the
archival survey data for previous outbursts is also encouraged.    

1RXS J231935.0+364705 page: http://hea.iki.rssi.ru/~denis/J2319+3647.html
------------------------------------------------------------------------------
Password Certification:  S.A.Grebenev (sergei at hea.iki.rssi.ru)
http://www.astronomerstelegram.org/?read=2282
==============================================================================