Optical follow-up observations of MASTER OT105123.02+672528.3
ATel #3849; K. V. Sokolovsky, K. O. Baryshev, S. A. Korotkiy
on 6 Jan 2012; 23:59 UT
Credential Certification: Kirill Sokolovsky (firstname.lastname@example.org)
Subjects: Optical, Cataclysmic Variable
Referred to by ATel #: 3889
The optical transient MASTER OT105123.02+672528.3 (ATel #3845)
was observed on 2012 January 6 from the Mountain station of
Kazan State University (Karachay-Cherkessia, Russia) using
a 80mm f/7.5 refractor telescope equipped with an unfiltered ST-8300M
The transient source was detected at position
10:51:22.86 +67:25:28.2 (+/-0.3", J2000) measured with respect to nearby
UCAC3 stars (Zacharias et al. 2010, AJ, 139, 2184) at unfiltered magnitude
15.08 (JD2455933.325). The magnitude zero-point was set using red magnitudes of
USNO-B1.0 (Monet et al. 2003, AJ, 125, 984) stars in the field of view.
No variability greater than 0.06m was detected within the 3.5h observing run.
We note that MASTER OT105123.02+672528.3 is likely associated with an
unidentified X-ray source 1RXS J105120.5+672550 from the
ROSAT All-Sky Survey Faint Source Catalogue (Voges et al., 2000, IAUC, 7432)
while there is no known radio source that could be associated with it.
The hardness ratios listed in the ROSAT catalog do not contradict
the hypothesis of this object being a cataclysmic variable.