TITLE: GCN CIRCULAR NUMBER: 35488 SUBJECT: GRB GRB240101C: Fermi GBM observation DATE: 24/01/05 18:41:54 GMT FROM: sumanbala2210@gmail.com S. Bala (USRA), B. Mailyan (Florida Tech) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 12:57:23.76 UT on 01 January 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240101C (trigger 725806648/240101540), which was also detected by the Swift/BAT-GUANO (J. DeLaunay et. al. 2023, GCN 35482), GRBAlpha (Dafcikova et al. GCN Circ. 35459) and AstroSat CZTI (Navaneeth et al. GCN 35478). The Fermi GBM on-ground calculated location, using the Fermi GBM trigger data has been reported at GCN 35451. The angle from the Fermi LAT boresight at the GBM trigger time is 69.0 degrees. The GBM light curve consists of one very short peak with a duration (T90) of about 0.35 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.256 s is best fit by a Comptonized Epeak function with Epeak = 286.4 +/- 21.8 keV, and alpha = 0.10 +/- 0.14. The event fluence (10-1000 keV) in this time interval is (1.19 +/- 0.07)E-6 erg/cm^2. The 64-msec peak photon flux measured starting from T0 in the 10-1000 keV band is 460.9 +/- 77.4 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 242.7 +/- 28.8 keV, alpha = 0.30 +/- 0.20 and beta = -2.50 +/- 0.39. 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/35488. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...