MASTER-SAAO: dwarf nova outburst (ampl>4)
ATel #7559; V. Vladimirov, V. Lipunov (Lomonosov MSU), D. Buckley (SAAO), E. Gorbovskoy, V. Kornilov, S. Antipin, N. Tiurina, P. Balanutsa, A. Kuznetsov, V. Chazov, E. Popova (Lomonosov Moscow State University, Sternberg Astronomical Institute), S. Potter, A. Kniazev, M. Kotze (The South African Astronomical Observatory), N. Budnev, K. Ivanov, O. Gress, S. Yazev, V. Poleshchuk (Irkutsk State University), A. Tlatov, D. Dormidontov, V. Senik, A. Parkhomenko, (Kislovodsk solar station of RAS Pulkovo observatory), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal University), Yu. Sergienko, V. Yurkov, A. Gabovich (Blagoveschensk State Educational University), V. Shumkov, S. Shurpakov (MASTER-Team)
on 25 May 2015; 17:21 UT
Credential Certification: Nataly Tyurina (email@example.com)
Subjects: Optical, Request for Observations, Cataclysmic Variable, Transient, Variables
MASTER OT J151715.06-440246.4 discovery - new dwarf nova outburst (Ampl>4m, no known VIZIER source)
MASTER-SAAO auto-detection system ( Lipunov et al., Advances in Astronomy, MASTER Global Robotic Net, 2010 ) discovered OT source at (RA, Dec) = 15h 17m 15.06s -44d 02m 46.4s on 2015-05-24.08205 UT.
The OT unfiltered magnitude is 17.9m (the limit is 18.9m).
There are 3 images with OT on 2015-05-24.08205, 24.086, 24.0898UT with m_OT=17.9, there are 2 images with m_OT=17.9 on 2015-05-24.739 and 2015-05-24.725UT. There is no minor planet at this place.
We have reference images without OT on 2015-04-12.01345 UT with 18.9 unfiltered magnitude limit and on 2015-02-28.908 with m_lim=18.9.
There are no known source in VIZIER database inside 5". So we can suggest the Dwarf Nova outburst with amplitude more then 4m.
The discovery and reference images are available at http://master.sai.msu.ru/static/OT/MASTER151715.06-440246.4.jpg
Spectral observations are required.
List of Optical Transients discovered by MASTER
MASTER Global Robotic Net