GCN Circular 26013

Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ)
report:

We observed GRB 191016A (Gropp et al. GCNC 26008) with the 50 cm robotic
telescope (D50) of Ondrejov observatory in the Czech Republic, obtaining a
series of 120s images starting at 17:55UT, i.e. 13.6h post trigger.

We do not detect the optical afterglow (Watson, GCNC 26010; Zheng et al.,
GCNC 26011 and others) in a combined 60x120s I-band image with exposure
mean time 14.6h after the GRB. A rough conservative detection limit of the
image is I(Vega) > 19.5; as mentioned before by Zheng et al., the proximity
of Moon makes any photometric measurement difficult.