GCN Circular 43308
Subject
Fermi GBM Sub-Threshold Detection of GRB 260102A
Event
Date
2026-01-02T17:59:21Z (4 days ago)
From
rhamburg@usra.edu
Via
Web form
R. Hamburg (USRA) reports on behalf of the Fermi-GBM Team:
SVOM/ECLAIRs detected GRB 260102A on 2026-01-02 at 04:10:03 UTC (Xie et al 2026, GCN 43295). There was no Fermi-GBM onboard trigger around this event time. An automated, blind search for gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no candidates.
The GBM Targeted Search [1], the most sensitive coherent search for GRB-like signals in GBM, identified a transient starting approximately 33 seconds after the ECLAIRs best imaging SNR time at 2026-01-02T04:09:45 (Xie et al 2026, GCN 43295). The transient is detected most significantly on the 32.768 s timescale with a false alarm rate of 1.1e-05 Hz, using a "normal" spectrum (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3) for a GRB. The Targeted Search localization is consistent with the ECLAIRs position.
[1] Goldstein et al. 2019 arXiv:1903.12597