TITLE:   GCN CIRCULAR
NUMBER:  14018
SUBJECT: GRB 121128A: WSRT radio observation
DATE:    12/11/28 23:16:59 GMT
FROM:    Alexander van der Horst at U of Amsterdam  <A.J.vanderHorst@uva.nl>

A.J. van der Horst (University of Amsterdam) reports on behalf
of a large collaboration:

"We observed the position of the GRB 121128A afterglow at 4.9 GHz with
the Westerbork Synthesis Radio Telescope at November 28 11.34 to
21.06 UT, i.e. 6.2 - 16.0 hours after the burst (GCN 14007).
We do not detect a radio source at the position of the optical
counterpart (GCN 14007). The three-sigma rms noise in the map around
that position is 69 microJy per beam. The formal flux measurement for
a point source at the position of the optical counterpart is 59 +/- 23 
microJy.

We would like to thank the WSRT staff for quickly scheduling and
obtaining these observations."