PTF observations of 1RXS J204455.9-115151
ATel #6312; P. J. Groot (Radboud University/Caltech), D. Levitan (Caltech), T. Prince (Caltech), S. R. Kulkarni (Caltech)
on 15 Jul 2014; 14:55 UT
Credential Certification: Paul Groot (email@example.com)
Subjects: Optical, Binary, Cataclysmic Variable, Transient, Variables
The source 1RXS J204455.9-115151 was recently detected in outburst by the ASAS-SN project (ATEL #6306, Holoien et al.). Archival data shows that the Palomar Transient Factory (PTF) has observed and detected the source 41 times over the time interval JD 2455010 - 2455793. One PTF observation failed to produce an automated measurement of the brightness of the source, due to a position jump during the exposure, but the source is clearly detected. The overall behaviour is similar to that found in the CRTS long-term light curve, with the source consistently detected. The median R-band magnitude is R=17.0, with short time-scale variations up to R=16.7 and down to R=17.4. One outburst of 1RXS J204455.9-115151 has been registered by PTF: on HJD = 2455734.85908 at R=13.04 (saturated) and on HJD = 2455734.87585 at R=13.14 (saturated). In the previous and subsequent observations on HJD = 2455725.88045 and HJD = 2455754.90606 the source was at its quiescent level. The X-ray detection of the source, the large amplitude quiescent variability and the shape of the ASAS-SN light curve point towards a slow dwarf nova outburst in a (intermediate) magnetic Cataclysmic Variable.