GCN Circular 7534

T. A. Fatkhullin, A. S. Moskvitin, V. V. Sokolov (SAO-RAS, Nizhnij Arkhyz), 
A. S. Pozanenko (IKI, Moscow), A. de Ugarte Postigo (ESO, Santiago), M. 
Jel�nek, J. Gorosabel and A. J. Castro-Tirado (IAA-CSIC Granada), on 
behalf of a larger collaboration, report:

"Following the detection of GRB 080328 by Swift (Perri et al. GCNC 
7525), we have obtained BVRI imaging and spectroscopy (3800-7500 A) with 
the 6.0m BTA SAO-RAS telescope starting on Mar 28.76 UT  (i.e. 12.4 hr 
after the onset of the event). A faint optical source (with R about 
22.5) consistent with the UVOT position (Ward et al. GCNC 7530) is 
detected in all frames, thus implying an upper limit of about 2.5 for 
the GRB 080328 redshift. Its brightness is not consistent with the 
extrapolation of the early decay reported by Guidorzi et al. (GCNC 7526) 
indicating significant contribution of the reverse shock emission in the 
FTN data. Our BTA spectrum (2 x 900s) shows only a faint continuum and 
nothing conclusive can be reported (except the non-existence of strong 
emission lines arising from an underlying host galaxy)."

This message can be quoted.

[GCN OPS NOTE(29mar08): Per author's request, 3 typos were fixed
in the Fatkhullin, Moskvitin and Pozanenko names.]