[vsnet-grb-info 7494] GRB 090328: Gemini South Redshift

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9053
SUBJECT: GRB 090328: Gemini South Redshift
DATE:    09/03/30 02:50:53 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

S. B. Cenko, J. S. Bloom, A. N. Morgan, and D. A. Perley (UC Berkeley)
report on behalf of a larger collaboration:

We have obtained optical spectra of the candidate UVOT afterglow (GCN
9046, 9048) of the Fermi GRB090328 (GCN 9044) with the Gemini Multi-Object
Spectrograph mounted on the Gemini South Telescope.  Observations began at
00:05 UT on 2009 March 29.

Our first 1500 second spectrum uses the R400 grating and covers the
approximate wavelength range from 4000-8000 A.  We find a single bright
emission line at observed wavelength ~ 6470 A that we identify as
[OII] 3727 at z = 0.736, along with an absorption doublet consistent with
Mg II 2796/2803 at the same redshift.  We therefore suggest that
this is the redshift of GRB090328.  Further observations are in progress.

We wish to thank the entire staff at Gemini observatory, in particular M.
Edwards and J. Blakeslee, for the prompt execution of our observations.