GCN Circular 4703
K. Aoki, T. Hattori (Subaru Telescope, NAOJ), K. S. Kawabata (Hiroshima University), and N. Kawai (Tokyo Tech) report on behalf of the Subaru GRB team: "We have obtained the optical spectra of the afterglow of GRB060206 (Morris et al., GCN 4682) with FOCAS attached to the Subaru 8.2 m Telescope on Mauna Kea. We have taken the spectra covering wavelength regions of 5000-10000 A at Feb 6.5 (UT) with a total exposure time of 4 hours. The spectral resolutions were about R=500-1000. The optical spectra clearly show rich absorption lines, with which we confirm the redshift of 4.05 (Fynbo et al. GCN 4692). We have detected C IV 1550, Fe II 1608, and Al II 1670 in addition to Si II, Si II*, O I, C II, and Si IV reported in GCN 4692. Besides the z=4.05 systems, we have found the z=2.26 and z=1.48 systems which show Mg II 2800 and Fe II absorption lines."