Аннотация:MASTER OT J030504.43+433641.2 detection - ampl >5mag
MASTER-Amur auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L )
discovered OT source at (RA, Dec) = 03h 05m 04.43s +43d 36m 41.2s on 2018-11-20.54828 UT during routine MASTER automatic Fermi trigger 564334514 inspection (but OT is not connected with this GRB).
The OT unfiltered magnitude is 15.9m (mlim=17.9m) at 2 inspect images. There is m_OT=15.8 on 2018-11-19 15:54:32.201 at MASTER-Kislovodsk 1 inspect image.
We have reference images without OT on 2014-10-01.54326 UT with unfiltered magnitude limit 19.0m (MASTER-Amur), on 2018-10-18 23:13:57 with marginally seen OT << mlim=19.8 (MASTER-Kislovodsk), on without OT on 2018-09-22 17:48:45UT with mlim=18.7 (MASTER-Tunka).
There is SDSS star ( and other) with rmag=21.3 in history.
MASTER unfiltered W=0.2B+0.8R, calibrated by USNO-B1 R2,B2/R1,B1.
It means more then 5mag of current outburst amplitude.
Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/030504.43433641.2.png
http://www.astronomerstelegram.org/?read=12232