GCN Circular 26122
Subject
GRB 191031D: COATLI Optical Observations
Event
Date
2019-11-01T05:13:02Z (6 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Diego Gonz��lez
(UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra
(UNAM), and Eleonora Troja (GSFC) report:
We observed the field of GRB 191031A (D'Ai et al., GCN Circ. 26101; Fermi GBM
Team, GCN Circ. 26102) with the COATLI 50-cm telescope and interim imager at the
Observatorio Astron��mico Nacional on the Sierra de San Pedro M��rtir
(http://coatli.astroscu.unam.mx) from 2019-11-01 02:47 UTC to 04:49 UTC (5.4 to
7.4 hours after the trigger), obtaining a total of 4530 seconds of exposure in
the w filter.
We do not detetect any uncataloged sources in the enhanced XRT error region
(Osborne et al., GCN Circ. 26117) to a 3-sigma limit of w = 23.2.
Our w magnitudes are calibrated against the Pan-STARRS1 catalog, are on an
approximate AB system (Becerra et al., 2019, ApJ, 872, 118), and are not
corrected for Galactic extinction in the direction of the GRB.
We thank the COATLI technical team and the staff of the Observatorio Astron��mico
Nacional.