TITLE: GCN CIRCULAR NUMBER: 38550 SUBJECT: GRB 241213A: SAO RAS optical upper limit DATE: 24/12/13 09:16:58 GMT FROM: Moskvitin Alexander at SAO RAS <mosk@sao.ru> O. I. Spiridonova and A. S. Moskvitin (SAO RAS), report on behalf of the GRB follow-up team. We observed the field of GRB 241213A (Gupta et al. GCN Circ. 38547) with the 1-m telescope of SAO RAS, Zeiss-1000 + CCD-photometer on December 12, 02:30:40--02:52:17 UT (t_mid - T0 = 1349 sec.), observations started 700 seconds after the trigger. We obtained 4 x 300 sec images in Rc band under poor seeing and weather conditions. Inside the XRT error circle we did not detect any significant object (as well as Lipunov et al., GCN Circ. 38548) down to the limiting magnitude of R_lim = 21.0, calibrated against nearby PS1 stars (magnitudes were converted with the Lupton 2005 equations and not corrected for the MW extinction). View this GCN Circular online at https://gcn.nasa.gov/circulars/38550. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...