TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2131 SUBJECT: GRB 030329 and SN 2003dh DATE: 03/04/10 04:56:26 GMT FROM: Ryan Chornock at UC Berkeley R. Chornock, R. J. Foley, A. V. Filippenko, M. Papenkova, and D. Weisz, University of California, Berkeley, report that inspection of CCD spectra (range 310-1000 nm) of GRB 030329, obtained on Apr. 8 UT with the Shane 3-m telescope at Lick Observatory, confirms the emergence of broad bumps (especially at rest-frame 500 nm) characteristic of the peculiar type-Ic supernovae 1998bw and 2002ap at early times, as announced by Matheson et al. in GCN 2107 and GCN 2120. The association between core-collapse supernovae and at least some of the long-duration GRBs thus seems solid. We expect the supernova features to continue strengthening with time relative to the power-law continuum of the GRB afterglow. P.S. This information also appears in IAUC 8114, but has been reposted here for the benefit of those GCN subscribers who do not read the IAU Circulars.