TITLE: GCN CIRCULAR NUMBER: 41004 SUBJECT: IceCube-250416A: DDOTI Optical Upper Limit DATE: 25/07/07 09:22:40 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), 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 observe the field of the IceCube250706A (gold) event (IceCube Collaboration, GCN Circ. 40994) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on the Sierra of San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of 2025-07-07 UTC. DDOTI observed from 06:32 UTC to 07:43 UTC (from T+17.3 h to T+18.5 h after the trigger) with a total exposure of 38 min, covering the total error region reported by IceCube (IceCube Collaboration, GCN Circ 40994). Comparing our observations to the USNO-B1 and PanSTARRS PS1 DR2 catalogues and after performed image subtraction against PanSTARRS PS1 DR2, we detect no uncatalogued sources within the observed field to a 10-sigma limiting AB magnitude of: w > 20.2. This upper limit is consistent with the non-detection reported by COLIBRI (Globus et al., GCN Circ. 41003). 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/41004. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...