[vsnet-grb-info 27548] GRB210312B (Integral alert 9073): Candidate optical afterglow by Ondrejov D50

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29651
SUBJECT: GRB210312B (Integral alert 9073): Candidate optical afterglow by Ondrejov D50
DATE:    21/03/12 22:05:41 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek at asu.cas.cz>

M. Jelinek, J. Strobl, S. Trcka, R. Hudec, C. Polasek (ASU CAS Ondrejov)
report:

We observed the position of the Integral trigger 9073 (GRB 210312.87 or B)
with the D50 robotic telescope of the Astronomical Institute Ondrejov, near
Prague, Czech Republic. We performed a series of 10s and 20s unfiltered
exposures starting 23.8 s after the trigger.

In the first images we detect a rapidly fading object not present in the
DSS catalogue at 10:23:15.312 +76:52:06.96 J2000.  The preliminary
magnitude of the
object in the earliest images was R~18m.