MASTER: bright OT discovered during Fermi trigger 512353690/GRB170328A inspection
ATel #10230; E. Gorbovskoy, V. Lipunov (Lomonosov MSU), D. Buckley (SAAO), R. Rebolo, M. Serra-Ricart (IAC), O. Gress, N. Tiurina, P. Balanutsa, V. Kornilov, V. Vladimirov (Lomonosov MSU, SAI)
on 31 Mar 2017; 01:41 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)
Subjects: Optical, Gamma Ray, Request for Observations, Gamma-Ray Burst, Transient, Variables
Referred to by ATel #: 10231
MASTER OT J184546.55-352847.6 discovery - possibly Fermi trigger 512353690/GRB170328A counterpart detection
MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 18h 45m 46.55s -35d 28m 47.6s on 2017-03-28.06645 UT during Fermi trigger 512353690(GRB170328A) inspection
https://gcn.gsfc.nasa.gov/other/512353690.fermi
(trigger time is 17/03/28 00:28:05.53UT).
The OT's unfiltered magnitude is 17.0m (mlim=19.0).
There are only 2 images of this area (large Fermi error-boxes MASTER observed in inspection mode) and OT is seen in both images on
Tstart=2017-03-28 01:35:41UT and
Tstart=2017-03-28 01:42:14UT with exposition duration 60s (each).
There is no minor planet at this place except (208700)_2002_JK with Vmag=20.4 and 0.6E,7.0S offset (doesn't have any connection with our OT).
We have reference image on 2016-05-14.93352 UT with unfiltered mlim= 19.1m, the nearest in time images of this area are in MASTER-IAC database on 2016-07-31 23:23:26 with mlim=19.4.
There is no any sources in VIZIER database, it means 22mag limit in history
Deep photometry and Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/MASTEROTJ184546.55-352847.6.jpg
MASTER Global Robotic Net
