TITLE: GCN CIRCULAR NUMBER: 40138 SUBJECT: GRB 250411A: DDOTI Optical Observations DATE: 25/04/12 15:05:03 GMT FROM: sahil.atri@students.uniroma2.eu Sahil Atri (U Roma), Rosa L. Becerra (U Roma), Alan M. Watson (UNAM), Eleonora Troja (U Roma), 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) and Margarita Pereyra (UNAM) report: We observed the field of the GRB 250411A detected by Fermi/GBM (Fermi GBM Team, GCN 40136) 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 2025-04-12 UTC from 07:13 UTC to 12:05 UTC (from T+12.9 h to T+17.8 h after the trigger) and obtained a total exposure of 1.94 hours. Comparing our observations to the USNO-B1 and Pan-STARRS PS1 DR2 catalogues, we detect no evident uncatalogued sources within the observed field to a 10-sigma limiting AB magnitude of: w > 18.93-19.65 This value is not corrected for the Galactic extinction. 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/40138. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...