[vsnet-grb-info 5857] GRB 080319B: Second & Third Epoch WSRT Radio Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7507
SUBJECT: GRB 080319B: Second & Third Epoch WSRT Radio Observations
DATE:    08/03/23 02:43:15 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst at science.uva.nl>

A.J. van der Horst (NASA/ORAU) reports on behalf of a large collaboration:

"We re-observed the position of the GRB 080319B afterglow at 4.9 GHz with
the Westerbork Synthesis Radio Telescope at March 21.84 to 22.03 UT and at
March 22.84 to 23.03 UT, i.e. 2.7 and 3.7 days after the burst (GCN 7427).

We do not detect a radio source at the position of the optical counterpart
(GCN 7428) at 2.7 days. The three-sigma rms noise in the map around that
position is 108 microJy per beam. We note that this upper limit is not
consistent with the almost simultaneous VLA detection at 4.86 GHz reported
in GCN 7506.
We tentatively detect a radio source at 4 sigma significance at 3.7 days,
with a flux density of 163 +/- 39 microJy.

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