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GCN Circular 9503

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

"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
observations."
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