[vsnet-grb-info 7200] GRB 090102: Hobby-Eberly Telescope Spectroscopy

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8774
SUBJECT: GRB 090102:  Hobby-Eberly Telescope Spectroscopy 
DATE:    09/01/03 07:13:58 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara at astro.psu.edu>

A. Cucchiara and D. B. Fox (Penn State) report:

"Starting on 2009 January 2.24 UT we used the Marcario LRS spectrograph
on the Hobby-Eberly Telescope (R ~ 230) to obtain a 1000s spectrum of
the optical afterglow of GRB 090102 (Mangano et al., GCN 8762, Covino
et al., GCN 8763).
The spectrum covers the wavelength range 4200 to 10,000 Angstrom.
Unfortunately the data were taken under bad seeing conditions and the
average S/N is ~5.

Based on a preliminary calibration we detect some absorption features which
we identify as the MgII doublet (2796,2803) and MgI(2856) at redshift z 
= 1.55.

This value is consistent with the redshift reported by de Ugarte Postigo 
et al.
(GCN 8766) and Cenko et al. (GCN 8773).

We thank the HET staff for performing this observation, in particular
John Caldwell."