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GCN Circular 9503

GRB 090423: WSRT Radio Observations
2009-06-11T23:45:46Z (15 years ago)
Alexander van der Horst at NASA/MSFC <>
A.J. van der Horst (NASA/MSFC/ORAU) reports on behalf of a large

"We observed the position of the high redshift GRB 090423 afterglow
at 4.9 GHz with the Westerbork Synthesis Radio Telescope at May 22
11.47 UT to 23.46 UT, i.e. 29.15 - 29.65 days after the burst (GCN 9198).
We do not detect a radio source at the position of the infrared counterpart
(GCN 9202). The three-sigma rms noise in the map around that position is
75 microJy per beam. The formal flux measurement for a point source at the
position of the optical counterpart is 44 +/- 25 microJy.

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