TITLE:   GCN CIRCULAR
NUMBER:  35619
SUBJECT: GRB 240123A: SAO RAS optical observations
DATE:    24/01/24 11:10:25 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

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

We observed the field of GRB 240123A (D'Ai et al., GCN #35602;
Scotton, GCN #35610) with the 1-m telescope of SAO RAS equipped
with the CCD photometer. We obtained 12 x 300 sec. images in Rc
band on Jan 24, 02:15:54 -- 03:42:02 UT (t_mid - T0 = 0.66194 days).

The OT (D'Ai et al., GCN #35602; Pankov et al., GCNs #35605, #35609;
Sasada et al., GCN #35618) is clearly detected in our stacked frame
with the brightness of R = 21.12 +/- 0.09.

The photometry is based on R2 magnitudes of nearby USNO-B1 stars.