[AAVSO-HEN] GRB 090205: VLT spectroscopic redshift

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TITLE:   GCN CIRCULAR
NUMBER:  8889
SUBJECT: GRB 090205: VLT spectroscopic redshift
DATE:    09/02/06 08:57:35 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo at brera.inaf.it>

C. C. Thoene, D. Fugazza, P. D'Avanzo (INAF-OAB), V. D'Elia, S. 
Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), 
G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI 
collaboration:

We observed the optical afterglow of GRB 090205 (D'Avanzo et al. GCN 
8887; Kruehler & Greiner GCN 8888) with the ESO VLT about 9.0 hours 
after the burst with the FORS1 camera in spectroscopic mode. We took a 
20 min spectrum covering the range 4000-9000 Angstrom (based on a 
preliminary wavelength calibration) with a resolution of R=440.

We detect a broad absorption feature around lambda_obs = 6800 Angstrom. 
Interpreting this feature as Ly-alpha absorption the inferred redshift 
is z = 4.6 in agreement with the photometric redshift reported by 
Kruehler & Greiner (GCN 8888).

We acknowledge excellent support from the ESO staff, in particular G. 
James and J. Smoker.