TITLE: GCN CIRCULAR NUMBER: 44279 SUBJECT: GRB 260412A: Fermi GBM Observation DATE: 26/04/12 21:58:16 GMT FROM: Eva MP at INAOE <eva.palafox@gmail.com> E. Palafox (INAOE) and U. Pathak (IIT Bombay) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 06:13:46.17 UT on 12 April 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260412A (trigger 797667231/260412260). which was also detected by SVOM/ECLAIRs (Wang et al. 2026, GCN 44276). The Fermi GBM on-ground location is consistent with the SVOM/ECLAIRs position. The angle from the Fermi LAT boresight is 35 degrees. The GBM light curve consists of a bright emission episode with multiple peaks with a duration (T90) of about 80 s (50-300 keV). The time-averaged spectrum from T0-19 to T0+60 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.28 +/- 0.07 and the cutoff energy, parameterized as Epeak, is 210 +/- 30 keV. The event fluence (10-1000 keV) in this time interval is (7.9 +/- 0.5)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+22 s in the 10-1000 keV band is 3 +/- 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/44279. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...