[ Previous | Next ]
ATEL # 2282; D.V. Denisenko (IKI, Moscow)
on 5 Nov 2009; 14:53 UT
Distributed as an Instant Email Notice (Request for Observations)
Password Certification: S.A.Grebenev (firstname.lastname@example.org)
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
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