GCN Circular 42772
Subject
GRB 251116C: NOT optical observations
Event
Date
2025-11-19T22:04:25Z (12 days ago)
From
Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>
Via
Web form
G. Corcoran (UCD), D. B. Malesani (DAWN/NBI and Radboud), A. Martin-Carrillo (UCD), L. Fuglsang (NOT) report on behalf of a larger collaboration:
We observed the location of the SVOM/ECLAIRs (Pillas et al., GCN 42703; Brunet et al., GCN 42703) and Swift/BAT (DeLaunay et al., GCN 42726) GRB 251116C, using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera.
Our observation covers ~90% of the 3'-radius BAT error circle (including XRT source #1; Evans et al., GCN 42721), and consists of six 300-s images in the r band, taken at a mean epoch of 2025 Nov 17.910 UT (1.245 days after the trigger).
Inside or in close proximity of XRT source #1, four objects (3 point-like) are detected in both the NOT and Legacy Survey images. Their photometry does not show significant variation by more than ~0.1 mag.
Image subtraction was performed using the Legacy Survey as reference template. No new sources are detected within the covered fraction of the BAT error circle, down to a 3 sigma limiting magnitude of r > 24.4. Our non-detection is consistent with the earlier reports by LCO (Turpin et al., GCN 42705) and SVOM/VT (Li et al., GCN 42712).