TITLE:   GCN CIRCULAR
NUMBER:  23669
SUBJECT: GRB 181228A: FRAM-ORM optical limit
DATE:    19/01/10 07:26:40 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Martin Masek, Petr Janecek, Sergey Karpov, Jakub Jurysek,
Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza
(Institute of Physics, Prague, CZ)

report:

The 25cm robotic telescope FRAM-ORM at La Palma (Spain)
reacted robotically to the alert of GRB181228A (Moss et
al, GCNC 23570), obtaining a series of 20s R-band images
starting at 02:53:51.1UT, i.e. 34s post trigger.

We do not detect any new source in comparison to USNO-B1.0
catalog neither in single images (3-sigma limit R>~17.1)
nor in a combined 20x20s frame (mean exp time 269s post
trigger, 3-sigma limit R>~18.7).


Martin Jelínek, +420602105255, +34617840945, lascaux.asu.cas.cz/mates
       Astronomický ústav AVČR, Ondřejov