[vsnet-grb-info 7961] GRB 090424: WSRT Radio Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9504
SUBJECT: GRB 090424: WSRT Radio Observations
DATE:    09/06/12 04:00:08 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <Alexander.J.VanDerHorst at nasa.gov>

A.J. van der Horst (NASA/MSFC/ORAU) and A.P. Kamble (University of
Amsterdam) report on behalf of a large collaboration:

"We observed the position of the GRB 090424 afterglow with the Westerbork
Synthesis Radio Telescope at 2.3 GHz at May 4 19.91 UT to May 5 3.34 UT,
and at 4.9 GHz at May 23 15.97 to 21.45 UT, i.e. 10.39 and 29.19 days
after the burst (GCN 9223) respectively.
We do not detect a radio source at the position of the optical counterpart
(GCN 9223). The three-sigma rms noise in the map around that position is
168 microJy per beam at 2.3 GHz and 132 microJy per beam at 4.9 GHz. The
formal flux measurement for a point source at the position of the optical
counterpart is 47 +/- 56 microJy and 84 +/- 43 microJy at 2.3 and 4.9 GHz
respectively.

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