TITLE: GCN CIRCULAR NUMBER: 32903 SUBJECT: GRB 221029A: Fermi GBM observation DATE: 22/11/01 13:34:55 GMT FROM: Joe Mangan at UCD joseph.mangan@ucdconnect.ie

J. Mangan (UCD), R. Dunwoody (UCD) and C. Meegan (UAH), report on behalf of the Fermi GBM Team:

At 01:05:27.31 UT on 29 October 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 221029A (trigger 688698332 / 21029045). The Fermi GBM Final Real-time Localization is reported in GCN 32900.

The GBM light curve consists of three emission episodes with a duration (T90) of about 27.7 s (50-300 keV). The time-averaged spectrum from T0+0.003 s to T0+28.416 s is best fit by a Band function with Epeak = 130.7 +/- 6.3 keV, alpha = -1.12 +/- 0.03, and beta = -2.15 +/- 0.04

The event fluence (10-1000 keV) in this time interval is (2.69 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.32 s in the 10-1000 keV band is 35.5 +/- 0.5 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/