[vsnet-grb-info 27495] GRB 210306A: DDOTI Afterglow Confirmation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29598
SUBJECT: GRB 210306A: DDOTI Afterglow Confirmation
DATE:    21/03/06 04:28:38 GMT
FROM:    Alan M Watson at UNAM  <alan at astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Simone Dichiara
(GSFC/UMD), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl Lopez
(UNAM), Diego Gonzalez (UNAM), Margarita Pereyra (UNAM), Srihari Ravi (ASU), and
Eleonora Troja (GSFC/UMD) report:

We observed the field of the Swift/BAT GRB 210306A (D'Elia et al., GCN Circ.
29597) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional
on Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) starting at
2021-03-06 04:07 UTC (from 14 minutes after the trigger).

We observed a region covering aproximately 7 degrees in RA and 10 degrees in
declination (about 70 square degrees) centered on the XRT position in the w
filter. We calibrated our images against the APASS catalog.

Compared to the USNO-B1, Pan-STARRS DR1, and APASS DR10 catalogs, we detect a
bright source at 08:39:50.04 +60:12:18.9 (J2000) fading from about w = 17. This
confirms the afterglow reported in UVOT observations by D'Elia et al. (GCN Circ.
29597)

We thank the staff of the Observatorio Astronomico Nacional in San Pedro Martir.