TITLE: GCN CIRCULAR NUMBER: 39107 SUBJECT: GRB 250129A: SAO RAS optical observations DATE: 25/01/31 12:29:18 GMT FROM: Moskvitin Alexander at SAO RAS <mosk@sao.ru> A. Moskvitin, O. Spiridonova, Yu. Sotnikova (SAO RAS), A. Ghosh, S. Razzaque (CAPP, University of Johannesburg) We observed the field of GRB 250129A (Beardmore et al., GCN 39066) with the SAO RAS 1-m telescope Zeiss-1000 on January 30, 23:46:43 -- January 31, 00:19:22 UT (t_mid - T0 = 43.298 hours = 1.8041 days). We obtained 5 x 300 sec. images in Rc band. The OT (Francile et al., GCN 39065; GCN 39075, Beardmore et al., GCN 39066, Schneider et al., GCN 39071, Belkin et al., GCN 39072; Izzo et al., GCN 39073; Izzo and Malesani, GCN 39074; Ghosh et al., GCN 39077; Schneider et al., GCN 39078; Brivio et al., GCN 39079; Siegel and Beardmore, GCN 39085; Zheng and Filippenko, GCN 39090; GCN 39102; Schlekat et al., GCN 39091; Antier et al., GCN 39096; Odeh et al., GCN 39097; Ferro et al., GCN 39098; Bochenek and Perley, GCN 39099; Malesani et al., GCN 39100; Romanov, GCN 39101; Watson et al., GCN 39104; Vinko et al., GCN 39105; Akl et al., GCN 39106) is clearly detected in the stacked frame with the brightness of R = 19.65 +/- 0.13 (calibrated against R2 magnitudes of nearby UNSO-B1 stars and not corrected for the MW extinction). View this GCN Circular online at https://gcn.nasa.gov/circulars/39107. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...