GCN Circular 8774
Subject
GRB 090102: Hobby-Eberly Telescope Spectroscopy
Date
2009-01-03T07:13:58Z (16 years ago)
From
Antonino Cucchiara at PSU <cucchiara@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."