[vsnet-grb-info 26637] GRB 201020A: VIRT optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28737
SUBJECT: GRB 201020A: VIRT optical observations
DATE:    20/10/22 02:04:54 GMT
FROM:    Priyadarshini Gokuldass at U. of the Virgin Islands  <priyadass.94 at gmail.com>

P. Gokuldass (UVI), R. Strausbaugh (UVI), N. Orange (OrangeWave Innovative
Science, LLC), D. Morris (UVI), A. Cucchiara (UVI/College of Marin) report:

We observed the field of GRB201020A (Ambrosi et al., GCN 28696) with the
0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 10-20-2020 starting at 23:11:52.3 UT (T+17.2
hrs). We performed a series of exposures in R filter with a total exposure
of 3140 s. The weather conditions were clear during the hours of
observation with an average airmass of 2.1.

We find no new source within the enhanced XRT position error circle
(Osborne et al., 28698) and report the following 3-sigma upper limit:

T_mid       ||Exposure     ||Filter      ||Limit
T+18 hrs   ||3140s          ||R            ||>20.6

The limit is estimated from comparison to nearby USNO B1 stars and is not
corrected for Galactic extinction. The VIRT is still in the commissioning
phase.

This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR AST
Award 1901296, and NSF HBCU-UP AST Award 1831682. This message can be cited.