TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4385
SUBJECT: GRB 051221A: WSRT Radio Observations
DATE:    05/12/22 10:38:02 GMT
FROM:    Alexander van der Horst at U of Amsterdam  <avdhorst@science.uva.nl>

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

"We observed the position of the GRB 051221A afterglow at 4.9 GHz with the
Westerbork Synthesis Radio Telescope at December 21 13.90 UT to 18.63 UT,
i.e. 12.05 - 16.78 hours after the burst (GCN 4363).
We do not detect a radio source within the SWIFT/XRT error circle (GCN
4366), in particular at the position of optical (GCN 4369) and infrared
(GCN 4368) counterparts. The formal flux measurement for a point source at
the position of the optical counterpart is 17 +/- 35 microJy."

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