TITLE:   GCN CIRCULAR
NUMBER:  21771
SUBJECT: LIGO/Virgo G299232: continued WHT observations of the field of SwiftJ014008.5+343403.6
DATE:    17/08/30 23:16:52 GMT
FROM:    Peter Jonker at SRON/RU  <p.jonker@sron.nl>

LIGO/Virgo G299232: continued WHT observations of the field of SwiftJ014008.5+343403.6

P.G. Jonker (SRON/RU), M. Fraser (UCD), S. Nissanke (RU), R.P. Fender (Oxford),
J. Broderick (ASTRON),  A. Rowlinson (UvA, ASTRON), R.A.M.J. Wijers (UvA), B.W.
Stappers (Manchester) report on behalf of the LOFAR Transients Key Science
project:

On Aug, 30, 2017, starting at 04:54 (UTC), we obtained r',i', and z'-band images
with an exposure time of 3x600, 600, and 600 sec, respectively, with the ACAM
instrument mounted on the William Herschel Telescope on La Palma (Spain) of the
optical transient reported by Emery et al. GCN21733. Seeing conditions were
mediocre with values as large as 2".

We do not detect a source at the reported position down to an SDSS-based AB
limiting magnitude of r', i', z' > 23.5, 21.5, 20.3 based on the faintest
sources detected in the field.