TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  269
SUBJECT: GRB 981220, radio observations
DATE:    99/03/03 18:44:34 GMT
FROM:    Dale A. Frail at NRAO  <dfrail@nrao.edu>

D. A. Frail (NRAO), S. R. Kulkarni (Caltech) and G. B. Taylor (NRAO)
report:

"We have been monitoring the radio source claimed to be a possible
afterglow candidate for GRB 981220 based on early observations at WSRT
(GCN #168) and the VLA (GCN #170). Observations made over a period of
75 days shows that the source has increased in flux density at 4.9 GHz
by nearly a factor of four. However, at 15 GHz the source has remained
constant, while at 8.5 GHz there are only small (<20%) variations.
The behavior of the radio light curves for this source does not
resemble that of previous radio afterglows. Further observations are
planned with the Very Long Baseline Array to ascertain the nature of
this unusual radio variable."

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