TITLE:   GCN CIRCULAR
NUMBER:  35828
SUBJECT: GRB 240225B: SAO RAS optical observations
DATE:    24/02/28 22:16:52 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin, O. I. Spiridonova (SAO RAS)
report on behalf of the GRB follow-up team.

We observed the field of GRB 240225B (Nakajima et al., GCN 35796;
Evans, GCN 35797; Joshi et al., GCN 35798; D'Ai et al., GCN 35810;
Kawakubo et al., GCN 35811) with the SAO RAS 1m telescope Zeiss-1000
equipped with CCD-photometer. We obtained 8 x 300 sec frames in the Rc
band on Feb. 28, 18:20:36--19:11:22 UT (t_mid - T0 = 2.9307 days).

The OT (Gompertz et al., GCN 35805; Liu et al., GCN 35812;
Malesani et al., GCN 35819; Wise et al., GCN 35820;
Gompertz & Malesani, GCN 35824; Pankov et al.,  GCN 35826)
is clearly detected in our stacked frame with the brightness of
R = 20.51 +/- 0.02.

The photometry is based on nearby SDSS stars (magnitudes converted
with Lupton 2005 equations).