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GCN Circular 22156

GRB 171124A: Fermi-LAT detection
2017-11-24T11:56:09Z (7 years ago)
Elisabetta Bissaldi at U.Innsbruk/IAPP <>
F. Longo (University and INFN, Trieste), M. Arimoto (Waseda University),
E. Bissaldi (Politecnico and INFN Bari) and M. Palatiello (University 
and INFN, Trieste)
report on behalf of the Fermi-LAT collaboration:

At 05:37:56.50 UT on November 24, 2017, Fermi-LAT
detected high-energy emission from GRB 171124A, which was also
detected by Fermi-GBM (trigger 533194681 / 171124235).

The best LAT on-ground location is found to be

RA, Dec = 335.52, 35.22 deg (J2000)

with an error radius of 0.18 deg (90 % containment, statistical error 

This was 19 deg from the LAT boresight at the time of the trigger.
More than 10 photons with Energy > 100 MeV are associated to
the GRB in 350 s. The highest-energy photon is a 3.5 GeV event,
which is observed 4 seconds after the GBM trigger.

A Swift ToO has been approved for this burst.

The Fermi-LAT point of contact for this burst
is Francesco Longo (

The Fermi-LAT is a pair conversion telescope designed to cover
the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.
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