TITLE: GCN CIRCULAR NUMBER: 38768 SUBJECT: GRB 250101A: OASDG optical observations DATE: 25/01/01 23:37:38 GMT FROM: luca.izzo@inaf.it L. D'Avino (OASDG/AstroCampania), and L. Izzo (INAF-OACn and DARK/NBI) report: We observed the field of GRB 250101A (Page et al., GCN #38752) using the 0.5-m T1 telescope of the Osservatorio Astronomico S. Di Giacomo, located in Agerola, Italy. Our observations started on 2025 January 1 at 16:57 UT, approximately 3.6 hours after the GRB trigger. We acquired a series of 8x300 s frames in the Rc and Ic filters. In the stacked images, we clearly detect the optical counterpart initially identified by Swift-UVOT (Page et al., GCN #38752) and reported by several other telescopes (Li et al., GCN #38753; Mohan et al., GCN #38754; Zhu et al., GCN #38755; Budnev et al., GCN #38756; Wu et al., GCN #38758; Zhu et al., GCN #38759; Moskvitin et al., GCN #38762, GCN #38765; Odeh & Guessoum, GCN #38763; Hu et al., GCN #38764). We measure a preliminary magnitude of Rc = 20.00 +/- 0.07 mag (AB), calibrated against nearby stars from the Pan-STARRS catalog, appropriately transformed to Rc and Ic magnitudes. View this GCN Circular online at https://gcn.nasa.gov/circulars/38768. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...