GCN Circular 10786
A. de Ugarte Postigo (OAB-INAF), A.J. Castro-Tirado (IAA-CSIC), A. Guijarro and M. Alises (CAHA) report on behalf of a larger collaboration: "We have observed the field of GRB 100522A (Troja et al. GCNC 10784) with the 3.5m CAHA telescope (+Omega2000) in J and Ks bands. The observations were obtained during twilight, with a very high background. In a preliminary analysis we do not detect any source within the XRT error circle in any of the images. The 3x60s combined J-band exposure, has a mean time 04:20:27 UT and a 3-sigma limiting magnitude of 17.9. The 4x60s combined K-band exposure has a mean time of 04:31:50 and a limiting magnitude of 16.3."