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GCN Circular 25769

HAWC-190916A: DDOTI Optical Observations
2019-09-17T04:39:42Z (5 years ago)
Alan M Watson at UNAM <>
Alan M. Watson (UNAM), Nat Butler (ASU), Eleonora Troja (GSFC/UMD), Rosa L.
Becerra (UNAM), Simone Dichiara (GSFC/UMD), Diego Gonzalez (UNAM), Alexander
Kutyrev (GSFC/UMD), William H. Lee (UNAM), Margarita Pereyra
<> (UNAM), and Tanner Wolfram (ASU) report:

We observed the field of HAWC-190916A (Ayala, GCN Circ 25766, 25768) with the
DDOTI wide-field imager at the Observatorio Astronomico Nacional on Sierra San
Pedro Martir ( from 2019-09-17 03:14 to 2019-09-17
04:17 UTC (2.0 to 3.1 hours after the trigger).

We obtained a total of 2340 seconds of exposure in the w filter. We calibrated
our images against the APASS catalog. Our 10-sigma limiting magnitude is w =

Comparing our 10-sigma detections against the USNO-B1 catalog, we detect no
reliable uncataloged sources with significant fading within 1.7 degrees of the
nominal coordinates.

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