Possible new VY Scl-type variable 1RXS J075330.1+044606
ATel #3927; K. Sokolovsky (ASC Lebedev/SAI MSU), D. Denisenko, A. Mescheryakov, A. Tkachenko (IKI), S. Korotkiy, V. Gerke (Ka-Dar Obs.)
on 15 Feb 2012; 12:32 UT
Credential Certification: Kirill Sokolovsky (kirx@scan.sai.msu.ru)
Subjects: Optical, Request for Observations, Cataclysmic Variable
Referred to by ATel #: 3928
We report the discovery of a possible new VY Scl-type cataclysmic
variable associated with previously unidentified X-ray source
1RXS J075330.1+044606. The variable optical object
USNO-B1.0 0947-0148659 (07:53:30.78 +04:45:56.3, J2000)
located 15" from the X-ray source listed in the ROSAT All Sky
Survey Faint Source Catalog (Voges et al., 2000, IAUC, 7432)
was identified from information listed in the USNO-B1.0 catalog
(Monet et al. 2003, AJ, 125, 984): B1=19.82, R1=19.01, B2=17.48,
R2=15.69, I=15.52 as suggested by Denisenko & Sokolovsky
(2011, AstL, 37, 91).
The lightcurve obtained from NEAT archival images
( http://skyview.gsfc.nasa.gov/skymorph ) shows the object
slowly varying between the high (~15m) and low (~20m) states.
Since April 2011 we have been monitoring USNO-B1.0 0947-0148659
with the Bradford Robotic Telescope ( http://www.telescope.org ).
During April and May 2011 the object was fainter than 18m.
After the seasonal gap due to the solar conjunction the object
was found to grow systematically at the rate of about 1.1m/100days.
Time series photometry with the 40cm telescope of the Ka-Dar
observatory (Karachay-Cherkessia, Russia) obtained on
February 11, 2012 revealed light variations around R=15.8
with an amplitude of ~0.4m and a possible periodicity of 0.133d.
The 1.5m Russian-Turkish telescope (TUBITAK National
Observatory, Turkey) spectrum obtained on February 10, 2012
shows Balmer emission lines, but no indication of HeI or HeII.
Based on the historical lightcurve and the absence of features
typical for magnetic cataclysmic variables in its spectrum we
conclude, that 1RXS J075330.1+044606/USNO-B1.0 0947-0148659 is
likely a VY Scl-type system currently rising from its low state.
Further time-resolved observations of this object are encouraged.
The spectrum, lightcurves and finding charts
