Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 2545

GRB 031203: spectoscopic evidence for a 1998bw-like SN
2004-03-16T13:48:49Z (20 years ago)
Daniele Malesani at SISSA-ISAS,Trieste,Italy <>
G. Tagliaferri, D. Malesani, G. Chincarini, S. Covino, D. Fugazza, M. 
Della Valle, L.A. Antonelli, S. Campana, A. Cucchiara, P. D'Avanzo, F. 
Fiore, G.L. Israel, D. Lazzati, A. Simoncelli, L. Stella, K. Stamatis, 
F.M. Zerbi, on behalf of a larger collaboration, report:

Continuous monitoring of the host galaxy of the INTEGRAL GRB 031203 
(Gotz et al., GCN 2459; Prochaska et al., GCN 2475) has been performed 
with the ESO telescopes at Paranal and La Silla. We acquired several 
exposures in the optical and NIR bands during the period December 03 - 
March 01 (up to three months after the high-energy event).

We confirm the variability reported by Bersier et al. (GCN 2544). The 
variability pattern is fully consistent with the evolution of a 
98bw-like SN at z=0.105 (as measured in our spectra and in agreement 
with Prochaska et al., GCN 2482), peaking approximately 20 days after 
the burst in the R band. The contribution of such emission is roughly 
30% of that of the host galaxy, as determined from the late-time photometry.

Spectra with the VLT were taken on Dec 20, Dec 30 and Mar 01 (17, 27, 
and 90 days after the GRB respectively) in an attempt to fully 
characterise the observed variability. Subtraction of the late-time 
spectrum (taken 90 days after the GRB) from the spectra taken close to 
the maximum of the rebrightening reveals the emergence of a spectrum 
closely resembling that of SN 1998bw. We therefore conclude that the 
observed rebrightening is due to a supernova (Malesani et al. in 

We thank the staff at the ESO telescopes (both Paranal and La Silla) for 
the extensive work in this campaign, and in particular Malvina Billeres, 
Olivier Hainaut, Swetlana Hubrig, Chris Lidman, Gianni Marconi, and 
Thomas Szeifert.

This message may be cited.
Looking for U.S. government information and services? Visit