GCN Circular 41408
Subject
GRB 250814A: Further GRAWITA TNG NIR observations
Event
Date
2025-08-18T06:30:03Z (6 days ago)
From
Paolo D'Avanzo at INAF - OAB <paolo.davanzo@inaf.it>
Via
email
P. D'Avanzo, (INAF-OAB), M.T. Botticella, L. Izzo (INAF - OACn), A. Rossi (INAF-OAS), V. D’Elia (ASI-SSDC), G. Greco (INFN), M.G. Bernardini (INAF-OAB), B. Patricelli (Univ. Pisa), E. Cappellaro (INAF-OAPd), E. Brocato (INAF-OAR), M. Pedani, G Mainella (INAF-TNG), on behalf of GRAWITA report:
We observed the field of GRB 250814A detected by Swift/BAT and Fermi/GBM (Caputo et al. GCN Circ. 41358; Fermi team, GCN Circ. 41357) and possibly associated with the sub-threshold GW trigger S250814bg (LVK, GCN Circ. 41364) with the Italian 3.6m TNG telescope, located in Canary Islands (Spain), equipped with the near-infrared camera NICS in imaging mode.
A series of images were obtained with the H filter starting on 2025-08-17T00:15:57 UT (i.e. 2.1 days post T0), centered at the position of the X-ray afterglow detected by Swift/XRT (Caputo et al. GCN Circ. 41358; Salvaggio et al., GCN Circ. 41379).
The two NIR sources reported by D'Avanzo et al. (GCN Circ. 41391) are clearly detected. From preliminary photometry we find no evidence for significant variability for both sources with respect to our previous epoch of observation (D'Avanzo et al. GCN Circ. 41391). We therefore conclude that these sources are likely unrelated with GRB 250814A.