[vsnet-alert 11587] Interesting OT CSS091019:220450+054852

[Denis Denisenko]

Catalina Real-Time Transient Survey has detected an outburst of the 
interesting new optical transient which appears to be a cataclysmic 
variable in a common proper motion pair of stars (CPMS)!

CSS091019:220450+054852 = OT_J220450+054852 = OT_J220449.7+054852
Alert Time (UT) 2009-10-19T03:32:51 Event Date (UT) 2009-10-19T03:30:29
RA(deg)=331.20731 Dec(deg)=5.81453 R1=15.43 R2=15.39 R3=15.38 R4=15.40

Link to the CRTS light curve and images:
http://nesssi.cacr.caltech.edu/catalina/20091019/910191071174104173.html

Previous bright Catalina outburst to 14.83m (!) was detected on 
2006-10-01, two fainter ones to 17.3-17.5m - in June 2005 and July 2007.

The interesting thing about this object is that it appears to have a red 
companion at the separation of 2" to the west with a common proper 
motion!  Comparison of POSS-I and POSS-II Red plates shows an apparent 
shift of about -0.6" in RA and 0.7" in Dec (about -15 and 20 mas/yr 
+/-5) during 39 years from Aug. 1953 to Aug. 1994.  USNO-B1.0 has 
similar proper motion values for the two stars consistent to each other 
within errors:

USNO-B1.0 0958-0572265  22 04 49.71  +05 48 52.4  pmRA=-14  pmDE=14
USNO-B1.0 0958-0572262  22 04 49.62  +05 48 52.9  pmRA=-10  pmDE=24

Star was also captured in a bright outburst (V=15.37!!!) on photovisual 
plate of 1983 Nov. 05.  GSC 2.3 coordinates are: 22 04 49.69 +05 48 52.4.

Color-combined (BRIR) DSS image of 4'x4' area around the variable is 
posted at http://hea.iki.rssi.ru/~denis/OTJ220450+054852-BRIR4x4.jpg (2x 
zoom to resolve two components).

Note: Catalina quiescence magnitudes around 19m may belong to the 
neighbouring red object (or, to be precise, to the blend of two stars), 
so the variable star itself may be well fainter than 20m at minimum, and 
the outburst amplitude can be 5 magnitudes or more.  Thus the object can 
be a UGSU dwarf nova.  Time series are encouraged.

Best regards,

Denis in Moscow

P.S. Yet another bright outburst is found on Palomar-NEAT images of 
2001-10-06 and 2001-10-13!