GCN Circular 37865
Subject
GRB 241025A: DDOTI Afterglow detection
Date
2024-10-25T04:50:00Z (2 months ago)
From
Margarita Pereyra Talamantes at IA-UNAM Ensenada <mpereyra@astro.unam.mx>
Via
Web form
Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa Becerra (UTOV), Simone Dichiara (PSU), Tzveti Dimitrova (ASU), Océlotl López (UNAM), Camila Angulo (UNAM), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM) and Eleonora Troja (UTOV) report:
We observed the field of the GRB 241025A detected by Swift (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir (http://ddoti.astroscu.unam.mx) on 2024-10-25 from 02:28 to 02:43 UTC, 51min to 1.1hrs after the event, obtaining a total of 11 minutes of exposure in the w filter.
We detect a source at 22:14:36.94 +83:34:31.9, consistent with the position of the UVOT afterglow (Ambrosi et al., GCN 37859 ; Jiang et al, GCN 37862), with the following magnitude and 10-sigma uncertainty: w = 20.20 +/- 0.19 mag.
Our photometry is calibrated against the APASS catalog, on an approximate AB system, and is not corrected for Galactic extinction in the direction of the GRB.
We thank the DDOTI technical team and the staff of the Observatorio Astronómico Nacional.