TITLE:   GCN CIRCULAR
NUMBER:  29780
SUBJECT: GRB210410A: Candidate optical afterglow by Ondrejov D50
DATE:    21/04/10 03:36:29 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

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

We observed the position of the Fermi/GBM GRB 210410A (Fermi, GCNC 29777)
with the D50 robotic telescope of the Astronomical Institute Ondrejov, near
Prague, Czech Republic.  We performed a series of 120 s unfiltered
exposures starting 56 min after the trigger.

Within the Swift/XRT error box (Melandri et al. GCNC 29778) we detect a
fading object at (269.7542, 45.3629) (17:59:01.00 +45:21:46.6 J2000
+/-0.3").  The preliminary magnitude 103 min after the trigger was r'(AB) =
21.5 +/- 0.2 and the object seems to fade with alpha ~ 0.95 +/- 0.27.