TITLE:   GCN CIRCULAR
NUMBER:  25085
SUBJECT: GRB 190718A: FRAM-Auger optical limit
DATE:    19/07/18 12:52:21 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Martin Jelinek, 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 30cm robotic telescope FRAM-Auger in Malargue
(Argentina) reacted robotically to the Swift/BAT alert
of GRB190718A (D'Elia et al., GCNC 25082), starting
with a series of 20s unfiltered images at 04:45:11 UT,
i.e. 236s post trigger.

We do not detect any new source at or around the
reported X-ray errorbox reported by Evans et al. (GCN
25084) at single frames or a combined 20 x 20s image
taken between 236s and 1123s after the initial trigger.
The combined exposure  has a limiting magnitude r'(AB)
= 18.0, as calibrated against the APASS Catalogue.