J. Gorosabel (IAA-CSIC, Spain), N. Huelamo (LAEFF-CAB/INTA-CSIC, Spain),
M. Fernandez (IAA-CSIC, Spain), M. Jelinek (IAA-CSIC, Spain), P. Kubanek
(IAA-CSIC, Spain), A. de Ugarte Postigo (OAB-INAF, Italy), A.J.
Castro-Tirado (IAA-CSIC, Spain), R.J. Smith (JMU, Liverpool, UK), C.G.
Mundell (JMU, Liverpool, UK), on behalf of a larger collaboration, report:
"We carried out I-band observations of the GRB 090727 XRT optical
afterglow (Smith et al. GCN Circ. 9719; GCN Circ. 9722) with the 1.23m
Calar Alto telescope. The observations were carried out on July
27.9646-28.0063 UT (0.45-1.45 hours post GRB) with an exposure time of
3600s. Very preliminary photometry yields I ~ 19.4 (Vega system) for the
afterglow, against USNO B1.0 star with I=18.72 placed at (RA_J2000,
DEC_J2000) = (21:03:49.099, +64:55:58.23)."