TITLE:   GCN CIRCULAR
NUMBER:  21737
SUBJECT: LIGO/Virgo G299232: WHT spectrum of MASTER OT J033744.97+723159.0
DATE:    17/08/28 21:07:42 GMT
FROM:    Peter Jonker at SRON/RU  <p.jonker@sron.nl>

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, 27, 2017, starting at 03.37 (UTC), we obtained three spectra with an
exposure time of 900 sec each, with the ACAM instrument mounted on the William
Herschel Telescope on La Palma (Spain) of the optical transient MASTER
OTJ033744.97+723159.0 reported by Lipunov et al. (GCN 21720). Analysis using
Gelato suggests that it is a supernova Type IIb before maximum taking the
redshift of NGC1343 of 0.0073 as input.