MASTER-Kislovodsk: dwarf nova outburst
ATel #7978; P. Balanutsa, V. Lipunov, E. Gorbovskoy, V. Kornilov, N. Tiurina, I. Gorbunov, A. Kuznetsov (M. V. Lomonosov Moscow State University, Sternberg Astronomical Institute), A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of the Pulkovo Observatory), O. Gress, N. M. Budnev, K. Ivanov (Applied Physics Institute, Irkutsk State University), R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian (The Instituto de Astrofisica de Canarias), D. Buckley, S. Potter, M. Kotze (South African Astronomical Observatory), V. Krushinski, I. Zalozhnykh (Ural Federal University), Yu. Sergienko, A. Gabovich, V. Yurkov (Blagoveschensk Educational State University)
on 1 Sep 2015; 21:19 UT
Credential Certification: Nataly Tyurina (firstname.lastname@example.org)
Subjects: Optical, Cataclysmic Variable, Transient, Variables
MASTER OT J002521.98+545036.7 - bright dwarf nova outburst (15.5m, Ampl>3.5m) with previous outbursts in 2011 and 2013
MASTER-Kislovodsk auto-detection system ( Lipunov et al., Advances in Astronomy, MASTER Global Robotic Net, 2010 ) discovered OT source at (RA, Dec) = 00h 25m 21.98s +54d 50m 36.7s on 2015-08-31.88513 UT.
The OT unfiltered magnitude is 15.5m (limit 18.2m).
The OT is seen in 2 images. There is no minor planet at this place. There is an USNO star in 1.6-2" with B2=19.72,R2=18.74, I=18.08. We have reference image on 2012-09-04.01507 UT with unfiltered magnitude limit 18.6m. There are previous outbursts in MASTER-Tunka database on 2011-10-31.600 with unfiltered m_OT=15.2, and on 2013-11-20.593 with unfiltered m_OT=15.7 and about 50 images without OT with 19.2-19.4 unfiltered mag limit between 2011, 2013 and current outburst in MASTER-Tunka and MASTER-Kislovodsk database.
So we can suggest dwarf nova outburst with amplitude more then 3.5m.
Spectral observations are required.
The discovery and reference images are available at http://observ.pereplet.ru/images/MASTEROTJ002521.98+545036.7.jpg
List of Optical Transients discovered by MASTER
MASTER Global Robotic Net