[AAVSO-HEN] GRB 080604: Gemini-North spectroscopy

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
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TITLE:   GCN CIRCULAR
NUMBER:  7818
SUBJECT: GRB 080604: Gemini-North spectroscopy
DATE:    08/06/04 20:46:50 GMT
FROM:    Klaas Wiersema at U of Leicester  <kw113 at star.le.ac.uk>

K. Wiersema (U. of Leicester), J. Graham (STScI), N. Tanvir, E. Rol (U. of 
Leicester), A. Levan (U. of Warwick) and A. Fruchter (STScI) report on 
behalf of a larger collaboration:

We observed the optical afterglow of GRB 080604 (GCNC 7800, 7801) with 
Gemini-North, using the GMOS-N instrument. Spectroscopy was performed with 
the R400 grism, using 4 x 450 seconds integration time, starting at
2008 June 04, 08:58 UT.

Several absorption lines of, among others, Fe II (2382,2586,2600), Mg II 
(2796,2803) and Mg I (2026,2852) are found at a redshift of 1.416. The 
discrepancy with respect to the redshift reported in GCN 7805 may be due 
to provisional calibration files used for the HET reduction (Cucchiara 
priv. comm.).

We thank the Gemini staff astronomers for their support in obtaining these 
observations.