GCN Circular 33748
A. Moskvitin, O. Maslennikova (SAO), N. Pankov (HSE, IKI) and A. Pozanenko (IKI), report on behalf of GRB follow-up team. We observed the field of GRB 230506C (Tohuvavohu et al., GCN 22731) with the SAO RAS 1-m telescope Zeiss-1000 + CCD photometer. The observations started since 1.3528 hours after the trigger under mediocre weather conditions. We obtained 3 x 300 sec. exposures in Rc band (May 6, 18:30:29 -- 18:48:26 UT, T_mid - T_0 = 1.5024 h). The OT (Kuin & Dichiara, GCN 33733; Pankov et al., GCN 33734; Jelinek et al., GCN 33735; Adami et al., GCN 33741) is marginally detected in the stacked image with the brightness of R = 20.5 +/- 0.3. Preliminary photometry is based on R2 magnitudes of nearby USNO-B1 stars. The OT magnitude is not corrected for the Galactic extinction.