TITLE: GCN CIRCULAR NUMBER: 41960 SUBJECT: GRB 250924A: DDOTI Detection of the Optical Counterpart DATE: 25/09/24 09:00:57 GMT FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra@roma2.infn.it> Rosa L. Becerra (U Roma), Sahil Atri (U Roma), Alan M. Watson (UNAM), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM), Margarita Pereyra (UNAM) and Eleonora Troja (U Roma) report: We observed the field of GRB 250924A detected by Swift (Siegel et al., GCN Circ. 41959) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir (http://ddoti.astroscu.unam.mx) on the night of 2025-09-24 UTC. DDOTI observed the Swift/UVOT position (Siegel et al., GCN Circ. 41959) from 08:35 UTC to 08:40 UTC (from T+17.3 to T+ 22.1 min after the trigger), obtaining a total exposure of 4 minutes. By comparing our observations with the USNO-B1 and Pan-STARRS PS1 DR2 catalogs, we detect an uncatalogued source with a preliminary AB magnitude of: w = 19.47 +/- 0.05. We thank the staff of the Observatorio Astronómico Nacional on the Sierra of San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/41960. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...