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GCN Circular 19403

GRB 160509A: Fermi-LAT prompt detection of a very bright burst
2016-05-09T09:42:59Z (8 years ago)
Elisabetta Bissaldi at U.Innsbruk/IAPP <>
F.Longo (University and INFN, Trieste), E.Bissaldi (Politecnico and INFN, Bari),
J. Bregeon (CNRS/IN2P3/LUPM), J. McEnery (NASA/GSFC), M. Ohno (Hiroshima U),
S. Zhu (AEI Potsdam-Golm/AEI Hannover) report on behalf of the Fermi-LAT team:

At 08:59:04.36 UTC on May 09, 2016, Fermi-LAT triggered on
high-energy emission from GRB 160509A,
also detected by GBM (trigger 484477130/160509374).

The onboard location is

RA, Dec 310.1, 76.0 (J2000)

with an estimated error radius of 0.50 deg
(90% containment, systematic error only).
This was 31.8 deg from the LAT boresight at the time of the trigger.

We anticipate providing a refined location within the next 12 hours
when the LAT science data for this burst is downlinked and processed.

We note that this is an extraordinarily bright GRB,
and strongly encourage additional observations.

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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