TITLE: GCN CIRCULAR NUMBER: 7650 SUBJECT: GRB 080430: Spectroscopy from CAHA DATE: 08/05/01 02:51:20 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo, L. Christensen (ESO), J. Gorosabel (IAA-CSIC), C. Thöne (Dark), D.A. Kann (TLS), A. Mora (UAM), T. Szeifert (ESO), M. Jelinek, A.J. Castro-Tirado (IAA-CSIC), S. Pedraz (CAHA), N. Cardiel, D. Montes (UCM). On behalf of a larger collaboration report: We have obtained spectroscopic observations of GRB 080430 from the 2.2m Calar Alto telescope (+CAFOS) starting at 21:11 UT (78 minutes after the burst). The observations consisted of 3x1200s integrations in low resolution. The signal to noise ratio is low but after a preliminary reduction we may conclude: 1) Continuum is clearly detected down to 3500 Angstroms, implying a redshift smaller than 1.9. 2) We detect an absorption feature at ~4900 Angstroms that we suggest to be the MgII doublet (2796.3, 2803.5), implying a most probable redshift of ~0.75. Further analysis is ongoing. Additional spectroscopic observations are encouraged. This message may be cited.