TITLE:   GCN CIRCULAR
NUMBER:  28146
SUBJECT: GRB 200716C: VIRT optical detection.
DATE:    20/07/19 22:10:18 GMT
FROM:    Priyadarshini Gokuldass at U. of the Virgin Islands  <priyadass.94@gmail.com>

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

We observed the field of GRB200716C (Ukwatta et al, GCN 28124) with the
0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 07-17-2020 starting at 01:48:10 UT (T+2.8
hrs). We performed a series of exposures in R filter with a total exposure
of 1210 s. The weather conditions were clear during the hours of
observation with an average airmass of 2.2.

We detect a source consistent with the UVOT position (Ukwatta et al, GCN
28124) and optical transient identified by others (Lipunov et al. 28125, Hu
et al. 28126, Kumar et al. 28138) with magnitude:

  R= 17.1 +/- 0.2

The magnitude is estimated from comparison to nearby USNO B1 stars and is
not corrected for Galactic extinction. Further analysis is in progress to
confirm the decaying nature of the source. 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.