TITLE:   GCN CIRCULAR
NUMBER:  45457
SUBJECT: GRB 260818B: TNG NIR observations
DATE:    26/08/28 10:09:39 GMT
FROM:    Riccardo Brivio at INAF-OAB <riccardo.brivio@inaf.it>

R. Brivio (INAF-OAB), D. B. Malesani (DAWN/NBI and Radboud), M. Ferro (INAF-OAB), A. Rossi (INAF-OAS), A. Melandri (INAF-OAR), M. De Pasquale (U. of Messina), V. Lorenzi (INAF-TNG) report on behalf of the CIBO collaboration:

We observed the field of GRB 260818B detected by SVOM/ECLAIRs (Cordier et al., GCN 45398) with the Italian 3.6m TNG telescope equipped with the near-infrared camera NICS. A series of images were obtained with the J filter starting on 2026-08-28 at 02:19:43 UT (i.e. 9.26 days after the trigger). 

The transient candidate identified by the COLIBRI telescope (Ducoin et al., GCN 45450) is not detected in the co-added image. We measure a 3-sigma limiting magnitude of:

J > 21.9 (Vega; calibrated against the 2MASS catalogue),
 at a mid-time of 9.28 days after the trigger.