TITLE: GCN CIRCULAR NUMBER: 35610 SUBJECT: Fermi GBM Sub-Threshold Detection of GRB 240123A DATE: 24/01/23 19:36:21 GMT FROM: Lorenzo Scotton at UAH <lscottongcn@outlook.com> L. Scotton (UAH) reports on behalf of the Fermi-GBM Team: Swift-BAT detected GRB 240123A at 11:05:46 UT (D'Ai et al. 2024, GCN 35602). There was no Fermi-GBM onboard trigger around the event. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no counterparts. The GBM targeted search [1], the most sensitive, coherent search for GRB-like signals identified a transient most significantly on the 8.192 s timescale, with a false alarm rate of 3.9e-05 Hz and a location consistent with the Swift-BAT event, using the standard search protocol with a S/N of 13. The GBM targeted search event was found with the highest significance with a "normal" spectrum (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3) for a GRB. [1] Goldstein et al. 2019 arXiv:1903.12597 View this GCN Circular online at https://gcn.nasa.gov/circulars/35610. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...