TITLE:   GCN CIRCULAR
NUMBER:  31714
SUBJECT: GRB 220306B: Mondy optical observations, confirmation afterglow candidate
DATE:    22/03/08 22:01:09 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI),  A. Pozanenko (IKI), E. Klunko (ISTP), R. Ya. 
Inasaridze (AbAO), N. Pankov (HSE)  report on behalf of GRB IKI FuN:

We observed  the field of Swift GRB 220306B (Caputo et al. GCN 31697)
which is also detected by GBM/Fermi (Wood  et al., GCN 31702) with 
AZT-33IK telescope of Mondy observatory  in   R-filter starting on
Mar. 07 (UT) 16:42:31. We  detected the  object (Belkin et al., GCN 
31705; Klose et al., GCN 31711) at the S-E edge of the enhanced XRT 
position (Evans et al. GCN 31700).   Due to non-optimal seeing we cannot 
discriminate a possible optical afterglow from the object.  Preliminary 
aperture photometry of the object is following

Date       UT start   t-T0    Filter Exp.    OT    Err.  UL(3sigma)
                        (mid, days)    (s)

2022-03-07 16:42:31   0.94924  R     20*120  21.20 0.22    22.0

The R magnitude of the object seems still to be brighter than R_mag 
deduced for the object assuming the object is a star. Taking into 
account results of  observations (Belkin et al., GCN 31705; this GCN) 
and Tautenburg observations (Klose et al., GCN 31711) we would more 
firmly suggest the object  is the afterglow of GRB 220306B. The object 
Pan-STARRS  objID  193630053894966412  could be a host galaxy of GRB 
220306B.