TITLE:   GCN CIRCULAR
NUMBER:  24370
SUBJECT: GRB 190501A: GOTO optical counterpart search
DATE:    19/05/02 16:52:17 GMT
FROM:    Danny Steeghs at U.of Warwick/GOTO  <dsteeghs@gmail.com>

J.Lyman(1), K.Ulaczyk(1), K.Wiersema(1), D.Steeghs(1),
M.Dyer(3), D.Galloway(2), V.Dhillon(3), P.O'Brien(4),
G.Ramsay(5), D.Pollacco(1), E.Thrane(2), S.Poshyachinda(6),
E.Palle(7),  R.Cutter(1), A.Levan(1), T. Marsh(1), R.West(1),
B.Gompertz(1), E.Stanway(1), K.Ackley(2), A.Obradovic(2),
Y-L.Mong(2), A.Casey(2), M.Brown(2), E.Rol(2), J.Mullaney(3),
S.Littlefair(3), L.Makrygianni(3), E.Daw(3), J.Maund(3),
R.Starling(4), R.Eyles(4), S.Tooke(4), U.Sawangwit(6),
D.Mkrtichian(6), S.Awiphan(6), S.Aukkaravittayapun(6),
P.Irawati(6), M.Kennedy(8), R.Breton(8), D.Mata-Sanchez(8),
 T.Heikkila(9), R.Kotak(9)
(1) Warwick University; (2) Monash University; (3) Univ. of Sheffield;
(4) University of Leicester; (5) Armagh Observatory & Planetarium;
(6) National Astronomical Research Institute of Thailand;
(7) Instituto de Astrofisica de Canarias; (8) Univ. of Manchester;
(9) University of Turku

report on behalf of the GOTO collaboration:

We report on optical observations with the Gravitational-wave Optical
Transient Observer in response to the AGILE detected GRB 190501A (Ursi
et al. GCN #24360).

The refined position reported in Verrecchia et al. (GCN #24363) was
covered with a set of 5x90s exposures starting at 2019-05-01T20:49
(15.4 hours after the burst) using our wide L filter (400-700 nm).

No viable counterpart is detected using a difference imaging
analysis based on recent survey observations of the same pointing. We
achieved a 5-sigma detection limit of g=20, based on a photometric
calibration against PS1 stars.


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/)