OGLE follow-up of MASTER nova alert - not nova, but short, possibly repeating transient
ATel #4221; Warsaw University Astronomical Observatory, OGLE team
on 27 Jun 2012; 22:01 UT
Credential Certification: Lukasz Wyrzykowski (wyrzykow@ast.cam.ac.uk)
Subjects: Optical, Transient
We report the results of the follow-up of the transient reported by MASTER (ATEL #4202) by the OGLE telescope (Udalski et al. 1997). The object was reported at RA=20:08:45.060, Dec=-35:54:03.80.
On 2012-06-23 08:57:31 UT (about 2 days after the detection) we obtained 15s exposure in the I-band and detected no new object at the reported position with the limit of about 19 mag (red circle on the image below).
Additionally, when we compared this field with the ESO-DSS2 I-band image (http://archive.eso.org/dss/dss) we noticed about 14 mag object at RA=20:08:45.7, Dec= -35:54:34.7, which is not present on the OGLE image (marked with green circle on the image below). It is located 31'' away from the position reported by MASTER, which is just 1.4 pixels of their MASTER-VWF CCD camera. However, the nature of the object visible on the DSS image is not certain, as it does not follow the PSF of nearby stars and could be some sort of an artefact, e.g. reflection.
We suggest that the transient reported by the MASTER team was likely an M-dwarf flare (UV Ceti-type transient), or some other short time-scale event, but not nova. We have also possibly detected a historic outburst of this transient in 1988, at slightly refined position RA=20:08:45.7, Dec= -35:54:34.7.
Follow-up OGLE image and DSS cutout: http://www.astrouw.edu.pl/~wyrzykow/transient-master-23062012-dss-ogle4.png
