TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  47
SUBJECT: GRB980329 near-IR observations
DATE:    98/04/05 00:54:00 GMT
FROM:    Don Lamb at U. of Chicago  <lamb@oddjob.uchicago.edu>


D. M. Cole, A. R. Cooray, J. M. Quashnock, D. E. Vanden Berk,
D. Q. Lamb, D. E. Reichart, G. T. Richards, K. Gloria, D. Long, and
T. Hoyes, University of Chicago, on behalf of the
Astrophysical Research Consortium (ARC), report:

"We made near-infrared observations (GCN #39, IAUC 6860)
of the SAX NFI error box for GRB 980329 (IAUC 6853, 6854)  
between Apr. 1.167 UT and Apr. 1.277 UT, using the GRIM II instrument 
mounted on the ARC 3.5-m telescope at Apache Point Observatory.
We find no detectable object, down to a limiting J magnitude of 20.9 +/- 0.5
(1 sigma) at the position R.A. = 7h02m38s.02, Decl. = +38o50'44" (J2000.0) of
the variable radio source VLA J0702+3850 proposed by Taylor et al. (GCN #40) 
to be the radio afterglow from GRB 980329. The measurement by Mannuci et al. 
(GCN #46) of a magnitude J = 19.2 (+0.8,-0.5) object at the position
of the radio source at epoch Mar. 29.84-29.86 UT implies
that this object dimmed by J magnitude 1.7 +/- 0.9 
during a period of approximately 2.4 days."

This report is citable.