MASTER: dwarf nova outburst
ATel #7873; O. Gress (ISU), V. Lipunov (Lomonosov MSU), D. Buckley (SAAO), E. Gorbovskoy, V. Kornilov, N. Tiurina, P. Balanutsa, A. Kuznetsov, V. Chazov, I. Gorbunov, D. Vlasenko (Lomonosov Moscow State University, Sternberg Astronomical Institute), S. Potter, M. Kotze (The South African Astronomical Observatory), N. Budnev, K. Ivanov (Irkutsk State University), A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk solar station of the Pulkovo observatory RAS), V. Krushinsky, I. Zalozhnih (Ural Federal University), Yu. Sergienko, V. Yurkov, A. Gabovich (Blagoveschensk State Educational University)
on 4 Aug 2015; 01:45 UT
Credential Certification: Nataly Tyurina (email@example.com)
Subjects: Optical, Request for Observations, Cataclysmic Variable, Transient, Variables
MASTER OT J185651.32-721019.9 - dwarf nova outburst with Ampl>3.7m
MASTER-SAAO auto-detection system ( Lipunov et al., Advances in Astronomy, MASTER Global Robotic Net, 2010 ) discovered OT source at (RA, Dec) = 18h 56m 51.32s -72d 10m 19.9s on 2015-08-01.79808 UT.
The OT unfiltered magnitude is 17.2m (the limit is 18.5m).
There are 6 images with OT in MASTER-SAAO database. There is no minor planet at this place.
We have reference image without OT on 2015-06-19.82932 UT with 20.9 unfiltered magnitude limit. There is USNO B1 star with B2=19.87, R2=20.02. So we can suggest the dwarf nova outburst with amplitude more then 3.7m.
Spectral observations are required.
The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/185651.32-721019.9.png
List of Optical Transients discovered by MASTER
MASTER Global Robotic Net