[vsnet-grb-info 24043] GRB 191101A: VIRT Optical Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26142
SUBJECT: GRB 191101A: VIRT Optical Upper Limits
DATE:    19/11/02 01:51:43 GMT
FROM:    Priyadarshini Gokuldass at U. of the Virgin Islands  <priyadass.94 at 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 GRB 191101A (A.P. Beardmore et al., GCN 26140;
P.A. Evans et al., GCN 26137, D'Ai et al., GCN 26135) with the 0.5m Virgin
Island Robotic Telescope (VIRT) on 11-01-2019 starting at 23:03:18 UT
(T+115m). We report on an initial series of exposures in Clear filter
totaling 110s with an observation midpoint of T+117m. The weather
conditions were very good during the hours of observation and the zenith
angle at the start of the observation was 63 degrees. We observed the Swift
XRT position with a 20'x20' field of view.



We find no new source at the Swift-XRT position and report a 3-sigma upper
limit of approximately V=17.0. 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.



Observations and analysis are ongoing. This message can be cited.