GCN Circular 46214
Subject
GRB 261108C: VLT/HAWK-I J-band upper limits
Event
Date
2026-11-10T11:21:16Z (a day ago)
From
Gregory Corcoran at University College Dublin <gregory.corcoran@ucdconnect.ie>
Via
Web form
G. Corcoran (UCD), A. Saccardi (CEA/Irfu), R. Brivio (INAF/OABr), S.D. Vergani (Observatoire de Paris/LUX) D. B. Malesani (DAWN/NBI and Radboud), report on behalf of the Stargate collaboration:
We observed the field of the SVOM/ECLAIRs GRB 261108C (Hamburg et al., GCN 46198) using the HAWK-I instrument installed on the ESO VLT UT4 (Yepun). Observations started at 06:30:57 UT on 2026 November 09 (9.2 hr after the trigger) and consisted of 20 x 60 s exposures in the J band.
Within our image, there are a number of objects consistent with the EP/FXT position (Huang et al., GCN 46212). With the exception of one Gaia-classified star, all objects within the FXT region are extended. Given the lack of deep enough template images in the J band, we cannot establish near-infrared variability, but we note that all of them are visible in archival stacks from the Dark Energy Survey. Therefore at the present time, we cannot identify a candidate counterpart to GRB 261108C. The 3-sigma limiting magnitude of our stacked image is:
J > 22.9 (AB)
Our photometry is calibrated using nearby stars in the VISTA Hemisphere Survey and is not corrected for Galactic extinction.
We acknowledge the excellent support from the ESO observing staff in Paranal, in particular Camila de Sa Freitas, Carlo Felice Manara, and Susana Cerda.