GCN Circular 55

M.R. Metzger (Caltech) reports:

Near-infrared K-band images of the area surrounding the variable radio source
detected by Taylor et al. (GCNC #40), possibly associated with GRB 980329
(IAUC 6853, 6854), were obtained on Apr 6.27 and Apr 8.28 with the Keck-I
10m telescope.  The source reported by Larkin et al. (GCNC #51, coincident
with the galaxy reported by Djorgovski et al., GCNC #41) was detected on
both nights, at K=21.4 +/- 0.2 mag (6.27) and K = 21.9 +- 0.4 mag (8.28).
Comparison with the magnitudes reported by Larkin et al. indicates that the
source has faded by about 1 mag between Apr 2.3 and Apr 8.28.  This suggests
that part of the K flux may be IR afterglow of GRB 980329.  It is consistent
with fading, detections, and upper limits reported previously (GCNC #41,
#46, #48, IAUC 6864, 6866, 6868).  Further measurements are suggested to
estimate the IR brightness of any underlying host.

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Mark R. Metzger, mrm@astro.caltech.edu
Caltech 105-24
Pasadena, CA  91125



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