TITLE:   GCN CIRCULAR
NUMBER:  24947
SUBJECT: GRB 190630C: ISON-Castelgrande optical upper limit
DATE:    19/07/01 20:07:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), S. Schmalz (KIAM), A. Pozanenko (IKI), A. Volnova 
(IKI),  E. Mazaeva  (IKI),  I. Molotov (KIAM) report on behalf of larger 
GRB IKI FuN collaboration:

We observed the field of GRB 190630C (Ukwatta et al., GCN 24927) with 
ORI-22 (22 cm) telescope of ISON-Castelgrande observatory in Clear 
filter starting on July 01  (UT) 00:03:42.  We do not detect any object 
within enhanced Swift-XRT position (Goad et al., GCN 24930). Preliminary 
photometry of the field is following

Date       UT start t-T0    Filter Exp.   OT    Err. UL
                     (mid, days) (s)

2019-07-01 00:03:42 0.02584  CR    53*60  n/d   n/d 18.8

The photometry is  based on nearby USNO-B1.0 (R2) stars.