TITLE:   GCN CIRCULAR
NUMBER:  32387
SUBJECT: GRB 220711B: 10.4 m GTC(+EMIR) observations
DATE:    22/07/13 18:43:53 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

R. Sanchez-Ramirez, Y.-D. Hu, I. Perez-Garcia, M.D. Caballero-Garcia, A.J. Castro-Tirado (IAA-CSIC) report on behalf of a larger collaboration:

We observed the field of GRB220711B (Fermi GBM team GCNC 32365, D'Ai et al. GCNC 32366) with the Espectrografo Multiobjeto Infra-Rojo (EMIR), mounted on the 10.4m Gran Telescopio de Canarias (GTC) in La Palma (Spain). Imaging observations started on Jul 12 at 00:32:14 (~4.3 hrs after the GRB) and were carried out in the J and Ks bands for a total exposure time of 1260s in each filter. The afterglow reported by Malesani et al. (GCNC 32368 and 32377) is clearly detected in a preliminary reduction of both filters, measuring J~21.3 AB.

A second epoch was obtained on Jul 12 at 23:31:10 in the J band, observing a decay of about 1 magnitude between both epochs. Further observations are planned.

We thank the excellent support from the GTC staff.