GCN Circular 12134
J.C.Tello, J. Gorosabel, A. Castro-Tirado, M. Fernandez (IAA-CSIC Granada, Spain) and N. Huelamo (CAB-CSIC Madrid, Spain) reports on behalf of a larger collaboration: We observed GRB110709A detected by Swift/BAT (Holland et al. 2011, GCN 12118) with CAHA 1.23m and OSN 1.5m telescopes. Centro Astron�mico Hispano Alem�n (CAHA) 1.23m's observation in R filter lasted from July 9th 20:35 to 21:42 UT (e.g. 5.18-6.29 hours after trigger). At 8x420 sec co-added frames centred on XRT position (Evans et al. 2011, GCN 12119) we do not detect any new source down to limiting magnitude R=22.7, calibrated against USNO B1.0. The I band frames from 1.5m Observatorio de Sierra Nevada (OSN) were taken on July 9th. On co-added I band frames, taken between 20:44 and 22:03 UT, with total exposure 4200 sec, we report limiting magnitude I=20.4 (calibrated against USNO B1.0). On V frames with total duration 1200 sec, acquired between 21:24 and 21:42 UT, we do not see any new source down to limiting magnitude V=21.6 (Calibrated against GSC 2.3). This message may be cited.