[vsnet-grb-info 20989] GRB 180805B: GOTO optical limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23087
SUBJECT: GRB 180805B: GOTO optical limits
DATE:    18/08/06 14:26:16 GMT
FROM:    Danny Steeghs at U.of Warwick/GOTO  <D.T.H.Steeghs at warwick.ac.uk>

G.Ramsay (Armagh O.), K.Ulaczyk, D.Steeghs, J.Lyman (U. Warwick),
M.Dyer (U. Sheffield),  B.Gompertz, A.Levan, R.Cutter (U. Warwick)
K. Ackley, D.Galloway, E.Rol (Monash U.), V.Dhillon (U. Sheffield),
P.O'Brien, R.Starling (U. Leicester), S.Poshyachinda (NARIT),
D.Pollacco (U. Warwick), E.Thrane (Monash U.), E.Palle (IAC)

report on behalf of the GOTO collaboration:

In response to GRB 180805B (D'Avanzo et al. GCN 23076), the
Gravitational-wave Optical Transient Observer (GOTO) observed the
field near the Swift BAT/XRT detection.

Observations started at 2018-08-06T04:37:59 UT (15.5 hours after the
burst) consisting of a set of 6x120s exposures in our wide L filter
(400-700nm). We do not detect any optical source within the error
circle of the enhanced XRT location (Evans et al. GCN 23077) with a
5-sigma limit of V=20.4, using APASS calibrators on the stacked image.

We note that our observations were obtained between those of Lupinov
et al. GCN 23085 and Malesani et al. GCN 23086.

GOTO is operated at the La Palma observing facilities of the University
of Warwick on behalf of a consortium including the University of
Warwick, Monash University, Armagh Observatory, the University of
Leicester, the University of Sheffield, the National Astronomical
Research Institute of Thailand (NARIT) and the Instituto de Astrofisica
de Canarias (IAC)

https://goto-observatory.org/