TITLE: GCN CIRCULAR NUMBER: 41378 SUBJECT: GRB 240814A: Fermi GBM Observation DATE: 25/08/14 20:20:15 GMT FROM: Cuán de Barra at UCD <cuan.debarra@ucdconnect.ie> C. de Barra (University College Dublin), P. McDermott (University College Dublin), and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 07:35:09.28 UT on 14 August 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250814A (trigger 776849714/250814316) which was also detected by Swift BAT (R. Caputo et al. 2025, GCN 41358). The Fermi GBM on-ground location is consistent with the Swift BAT position. The GBM trigger was temporally coincident with the non-significant compact binary merger candidate S250814bg (LVK Collaboration, GCN 41364) with GBM triggering 3.7s after S250814bg. The angle from the Fermi LAT boresight is 25 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 22 s (50-300 keV). The time-averaged spectrum from T0-6.1 to T0+16.4 s is best fit by a simple power law function with index -1.63 +/- 0.04.The spectrum is equally well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.15+/- 0.15 and the cutoff energy, parameterized as Epeak, is 132 +/- 24 keV. The event fluence (10-1000 keV) in this time interval is (2.9 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.6 s in the 10-1000 keV band is 1.4 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/41378. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...