TITLE: GCN CIRCULAR NUMBER: 10953 SUBJECT: GRB 100713A: TELMA and 1.5m OSN optical observations DATE: 10/07/13 22:21:28 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia F. J. Aceituno, J. C. Tello, M. Jelínek, P. Kubánek, J. Gorosabel, S. Guziy, A. J. Castro-Tirado (IAA-CSIC Granada) and A. de Ugarte Postigo (INAF-OAB Brera), report: "Following the detection of GRB 100713A by INTEGRAL (Mereghetti et al. GCNC 10951), we have obtained optical images with the 0.6m TELMA robotic telescope at the BOOTES-2 station and with 1.5m telescope at the Observatorio de Sierra Nevada (OSN), both located in Southern Spain. At the position of the X-ray afterglow detected by SWIFT/XRT (D'Elia et al. GCNC 10952) we do not detect any optical source down to I = 23 in the co-added 1.5m OSN image (3600-s exposure at 21:07 UT, i.e. 6.5-hr after the onset of the burst). Due to the low Galactic extinction (Av = 0.2), this INTEGRAL GRB is very suitable for follow up. Deeper observations (specially at near-IR wavelengths) are encouraged". This message can be quoted.