[vsnet-grb-info 23974] Possible GRB 191025A: FRAM-Auger optical limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26073
SUBJECT: Possible GRB 191025A: FRAM-Auger optical limit
DATE:    19/10/25 17:14:29 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek at 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 GRB191025A (Page et al., GCNC 26072), starting
with a series of 20s unfiltered images at 02:47:17 UT,
i.e. 30s post trigger.

We do not detect any new or strongly variable source at
or around the reported gamma-ray errorbox at single
frames or combined 10 x 20s exposures taken between 30s
and 585s after the initial trigger. The combined
images have a limiting magnitude r'(AB) = 19.1, as
calibrated against the APASS Catalogue.