[vsnet-grb-info 26690] GRB 201026A: FRAM-ORM optical detection limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28790
SUBJECT: GRB 201026A: FRAM-ORM optical detection limit
DATE:    20/10/27 08:33:15 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek at asu.cas.cz>

Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Sergey  Karpov, Martin  Masek,  Petr  Janecek, 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 GRB201026A (Cenko  et al
GCNC  28784), obtaining  a series  of 20  s unfiltered  images
starting at 22:50:58.9 UT, i.e. 13.4 min post trigger.

We  do not  detect  any  new source  within  or  near the  XRT
errorbox  neither in  single  images  (3-sigma limit  R>~17.1,
(Vega), calibrated  by the  Atlas catalog)  nor in  a combined
15x20s frame  (mean exp time  21.15 min post  trigger, 3-sigma
limit R>~18.5) similarly to Lipunov  et al. (GCNC 28783), Izzo
et al. (GCNC 28785) and Zhu et al. (GCNC 28786)