[vsnet-grb-info 8977] GRB 100302A: Gemini-North redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10466
SUBJECT: GRB 100302A: Gemini-North redshift
DATE:    10/03/03 16:38:03 GMT
FROM:    Ryan Chornock at UC Berkeley  <chornock at astro.berkeley.edu>

R. Chornock (Harvard), A. Cucchiara, D. Fox (Penn St.), and E. Berger (Harvard)
report on behalf of a larger collaboration:

Further analysis of the Gemini-North GMOS spectrum of the afterglow (Huang et
al., GCN 10461) of GRB 100302A (Cummings et al., GCN 10458) described in GCN
10465 (Cucchiara et al.) reveals that the afterglow shows a sharp increase in
continuum flux redward of 7100 Angs, with only a weak continuum detected between
5500 and 7000 Angs, consistent with absorption by H I at z~4.8.
There are several narrow absorption features superposed on the noisy red
continuum, consistent with N V, Si II, Si II*, and C II at a mean redshift of
4.813, which we identify as the redshift of this burst.