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GCN Circular 22249

GRB 171212B: Fermi GBM observation
2017-12-12T22:51:03Z (6 years ago)
Elisabetta Bissaldi at U.Innsbruk/IAPP <>
E. Bissaldi (Politecnico & INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 10:24:18.51 UT on 12 December 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171212B (trigger 534767063 / 171212434),
which was also detected by the Fermi-LAT (Kocevski et al. 2012, GCN 22247).
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 11 degrees.

The GBM light curve consists of a multipeak emission episode
with a duration (T90) of about 32 s (50-300 keV).
The time-averaged spectrum from T0 to T0+32 s is
adequately fit by a Band function with Epeak = 74 +/- 9 keV,
alpha = -0.95 +/- 0.13, and beta = -2.32 +/- 0.15.

The event fluence (10-1000 keV) in this time interval is
(5.744 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+27 s in the 10-1000 keV band
is 5.0 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
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