A. J. Castro-Tirado (IAA-CSIC Granada), T. A. Fatkhullin, A. S. Moskvitin,
A. F. Valeev, V. N. Komarova, V. V. Sokolov (SAO-RAS Zelenchuk), R.
S�nchez-Ram�rez, F. J. Aceituno, B.-B. Zhang, Y. Hu, J. C. Tello
(IAA-CSIC), S. B. Pandey (ARIES) and G. Lombardi (GTC La Palma), on behalf
of a larger collaboration, report:
�Following the detection of GRB 160629A by INTEGRAL (Gotz et al. GCNC
19621), optical spectra of the optical counterpart (Klotz et al. GCNC
19622, Sokolov et al. GCNC 19623) were obtained at both the 6.0m BTA
telescope in Zelenchuk (Russia) and at the 10.4m GTC in La Palma (Spain)
starting at 22.57 (June 29) and 4:39 (June 30) UT (i.e. 0.6 and 8.3 hr
postburst) respectively. A preliminary analysis shows a deep Lyman-alpha
trough and several metal absorption lines (SiII, SiII*, CII, SiIV, CIV,
FeII, and AlII, amongst others) at a common redshift of z = 3.332, which
we propose to be the redshift of the GRB host galaxy."