GCN Circular 23833

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

report on behalf of the GOTO collaboration:

In response to Swift BAT trigger 887217 (GRB190202A; Lien et al.
GCN 23830
Not found
 
 
), the Gravitational-wave Optical Transient Observer (GOTO)
observed the survey field covering the Swift BAT/XRT positions.

Due to adverse weather, observations started at 2019-02-02T03:51:41
(2.2 hours post burst) consisting of a set of 5x120s exposures in our
wide L filter (400-700nm).

We detect the optical counterpart coincident with the revised XRT
position reported in Evans et al. (GCN 23832
Not found
 
 
) at a S/N of 18.
Preliminary pipeline photometry based off a PS1 zeropoint provides
g=19.1 +/- 0.2, with the  uncertainty including a systematic error
component due to the calibration uncertainty. This has not been
corrected for galactic extinction.


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/)