Аннотация:MASTER OT J031957.28+771122.8 discovery - new OT, preliminary dwarf nova outburst, ampl>6m
MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 03h 19m 57.28s +77d 11m 22.8s on 2018-04-29.83595 UT during Fermi trigger inspection (but this OT is not connected with GRB). The OT unfiltered magnitude is 17.2m (mlim=17.7m).
We reobserved it on 2018-05-03 18:00:32 with unfiltered m_OT=17.5 and mlim=19.5.
There is no known sources in VIZIER database, taking into account surrounding Sloan stars with for ex. g=23.93;r=23.52 (50.04456;+77.20264), the amplitude of current MASTER OT outburst is more then 6m
We have reference image without OT on 2012-10-17.80035 UT with unfiltered magnitude limit 19.5m.
Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/031957.28771122.8.png