TITLE:   GCN CIRCULAR
NUMBER:  11112
SUBJECT: GRB 100816A: 1.23m CAHA optical observations
DATE:    10/08/16 18:39:32 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

V. Terron, M. Fernandez, A.J. Castro-Tirado, J. Gorosabel (IAA-CSIC),  
report on behalf of a larger collaboration:

We carried out BVRI-band observations of the Swift GRB 100816A  (Oates  
et al., GCNC 11102) with the 1.23m Calar Alto telescope. The optical  
afterglow (Oates et al., GCNC 11102; Antonelli et al., GCNC 11104) is  
well detected in BVRI with a preliminary magnitude of I~19.9 on Aug  
16.0492 UT (~33 min post burst), calibrated using USNO-B1.0 field stars.