TITLE:   GCN CIRCULAR
NUMBER:  39424
SUBJECT: GRB 250221A: Mondy optical observations
DATE:    25/02/22 12:25:53 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <grb.alex@gmail.com>

N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunlo (ISTP), A. Volnova
(IKI) report on behalf of IKI GRB FuN:

We observed the optical afterglow (Francile et al., GCN 39395; Watson et
al., GCN 39397; Melandri et al., GCN 39406; Shilling et al., GCN 39409; Guo
et al., GCN 39412; Muenter et al., GCN 39417; Palmerio et al., GCN 39418;
Pankov et al., GCN 39422) of the Swift GRB 250221A (Caputo et al., GCN
39396) with AZT-33IK telescope of Mondy observatory starting on 2025-02-21
(UT) 12:25:52 in R filter.

The afterglow is clearly detected. Preliminary photometry of the afterglow
in the stacked image is the following

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

2025-02-21 12:25:52 0.38490 23x60 R 20.30 0.05 22.5

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