GCN Circular 40915
Subject
GRB 250703A: DDOTI Optical Upper Limit
Event
Date
2025-07-03T14:00:42Z (18 hours ago)
From
sahil.atri@students.uniroma2.eu
Via
Web form
Sahil Atri (U Roma), Rosa L. Becerra (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 250703A detected by Fermi/GBM (Fermi GBM Team, GCN Circ. 40909) 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 2025-07-03 UTC.
DDOTI observed the Fermi/GBM error region, covering about 92% of the statistical error region (Fermi GBM Team, GCN Circ. 40909). DDOTI observed the field of GRB 250703A from 09:19 UTC to 11:22 UTC (from T+ 0.2 h to T+ 2.2 h after the trigger) and obtained a total exposure of 56 minutes, alternating with other scientific programs.
Comparing our observations to the USNO-B1 and Pan-STARRS PS1 DR2 catalogues, we
detect no uncatalogued fading sources within the observed field down to a 10-sigma limiting AB magnitude of:
w > 20.8
This value is not corrected for the Galactic extinction.