{
  "createdOn": 1751880160936,
  "format": "text/plain",
  "eventId": "IceCube-250416A",
  "bibcode": "2025GCN.41004....1B",
  "subject": "IceCube-250416A: DDOTI Optical Upper Limit",
  "body": "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:\n\nWe 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.\n\nDDOTI 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).\n\nComparing 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:\n\nw > 20.2.\n\nThis upper limit is consistent with the non-detection reported by COLIBRI (Globus et al., GCN Circ. 41003).\n\nThis value is not corrected for the Galactic extinction.\n\nWe thank the staff of the Observatorio Astronómico Nacional on the Sierra of San Pedro Mártir.\n\n",
  "circularId": 41004,
  "submitter": "Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra@roma2.infn.it>",
  "submittedHow": "web"
}