GCN Circular 7650

A. de Ugarte Postigo, L. Christensen (ESO), J. Gorosabel (IAA-CSIC),
C. Th�ne (Dark), D.A. Kann (TLS), A. Mora (UAM), T. Szeifert (ESO),
M. Jelinek, A.J. Castro-Tirado (IAA-CSIC), S. Pedraz (CAHA),
N. Cardiel, D. Montes (UCM). On behalf of a larger collaboration report:

We have obtained spectroscopic observations of GRB 080430 from the 2.2m
Calar
Alto telescope (+CAFOS) starting at 21:11 UT (78 minutes after the
burst). The
observations consisted of 3x1200s integrations in low resolution. The
signal to noise
ratio is low but after a preliminary reduction we may conclude:

1) Continuum is clearly detected down to 3500 Angstroms, implying a
redshift smaller
than 1.9.
2) We detect an absorption feature at ~4900 Angstroms that we suggest to
be the
MgII doublet (2796.3, 2803.5), implying a most probable redshift of ~0.75.

Further analysis is ongoing. Additional spectroscopic observations are
encouraged.

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