TITLE:   GCN CIRCULAR
NUMBER:  27341
SUBJECT: GRB 200306C: VIRT optical upper limits
DATE:    20/03/07 17:53:18 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 (College of Marin), R. Strausbaugh (UVI) report:


We observed the field of GRB200306C (Gropp et al., GCN 27326) with the 0.5m
Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 03-07-2020 starting at 01:52:04 UT (T+3.0
hrs). We performed a series of exposures in R filter. The weather
conditions were clear during the hours of observation and the zenith angle
at the start of observations was 68 degrees and rising. We observed the
Swift XRT position with a 20'x20' field of view.

We find no new source at the position of previous optical
detections (Lipunov et al., GCN 27325, Jelinek et al., GCN 27328,
Castro-Tirado et al., GCN 27329, Moskvitin et al., GCN 27333, Izzo et al.,
GCN 27334, Kann et al., 27335) and report upper limits as follows:

T_mid       ||Exposure     ||Filter      ||Limit
T+3.3 hrs      ||1025s          ||R           ||18.0
T+4.0 hrs      ||3360s          ||R           ||19.0

The limits are estimated from comparison to nearby USNO B1 stars and are
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.