GCN Circular 19092

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory

N.Tyurina, E. Gorbovskoy, V. Lipunov, V.Kornilov, P.Balanutsa, A.Kuznetsov, 
D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was pointed to the  GRB160225.81 (FERMI GBM TRIGGER NUM 
478121069) 33 sec after notice time and 77 sec
  after trigger time at 2016-02-25 19:25:42 UT. On our first (20s exposure) 
set we do not   found OTs FERMI initial error-box (ra=10 21 21  dec=-28 35 59
r=4.8 degreeas ) brighter then 15.3 .

After  2 hours we started inspection  new error box and found 
MASTER OT J095503.19-355149.4 . This source are not inside initial 
images.

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 09h 
55m 03.19s -35d 51m 49.4s on 2016-02-25.89505 UT. Errors are ~0.7 arcsec.
The OT unfiltered magnitude is 18.1m (limit 19.3m).

The OT is seen in 3 images. There is no minor planet at this place.

We have reference image without OT on 2015-01-17.92448 UT with unfiltered 
magnitude limit 19.7m.

Spectral observations are required.

The discovery and reference images are available at:

http://master.sai.msu.ru/static/OT/095503.19-355149.4.png

The OT position inside last error box (very close to center) is available 
at http://master.sai.msu.ru/static/OT/MAP095503.19-355149.4.png


The message may be cited.