TITLE:   GCN CIRCULAR
NUMBER:  8062
SUBJECT: GRB 080805: VLT redshift
DATE:    08/08/05 14:21:31 GMT
FROM:    Pall Jakobsson at U Hertfordshire  <P.Jakobsson@herts.ac.uk>

P. Jakobsson (U. Hertfordshire), P. M. Vreeswijk (DARK/NBI),
A. de Ugarte Postigo (ESO), D. Malesani, J. P. U. Fynbo (DARK/NBI)
and J. Sollerman (DARK/NBI; U. Stockholm) report on behalf of a
larger collaboration:

Using FORS2 on the ESO Very Large Telescope, we have obtained
low and medium resolution spectra (grisms 300V, 1200R and 1400V)
of the optical afterglow of GRB 080805 (Kruehler et al., GCN 8060;
de Ugarte Postigo et al., GCN 8061). The first spectrum was
taken approximately an hour after the burst.

A firm upper limit of z < 2.2 can be placed on the redshift
of GRB 080805 from the lack of Ly-alpha forest lines in the
spectrum of the afterglow. This is consistent with the GROND
observations (Kruehler et al).

The spectra display Fe II (2344,2382,2600) and the Mg II
doublet (2796,2803) in absorption corresponding to a redshift
of z = 1.20. There is also tentative evidence of an absorption
system at z = 1.50 (Fe II and Mg II), but further analysis is
required to confirm the reality of this system.

We thank the Paranal staff for excellent support, especially
Patricia Guajardo and Yuri Belestky.