TITLE:   GCN CIRCULAR
NUMBER:  20942
SUBJECT: GRB 170329A: Fermi-LAT detection
DATE:    17/03/29 15:31:29 GMT
FROM:    Manal Yassine at IN2P3/LUPM/CNRS  <manal.yassine@lupm.in2p3.fr>

M. Yassine (LUPM, Montpellier) ,E. Bissaldi (Politecnico & INFN Bari), 
G. Vianello (Stanford), J. L. Racusin (NASA/GSFC),
F. Longo (University and INFN, Trieste) and N. Omodei (Stanford) report 
on behalf of the Fermi-LAT team:

At 09:17:06.94 UT on March 29, 2017, Fermi-LAT detected high-energy 
emission from GRB 170329A, which was also detected by Fermi-GBM 
(170329387/512471831).

The best LAT on-ground location is found to be RA, Dec 356.6, 9.8 
(degrees, J2000) with an error radius of 0.6 deg (90% containment, 
statistical error only).
This was 33 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase in the event 
rate that is spatially and temporally consistent with the GBM emission.
More than 37 photons above 100 MeV  observed within 1 ks.
The highest-energy photon is a 0.8 GeV event which is observed 4 seconds 
after the GBM trigger.

The Fermi-LAT point of contact for this burst is Manal Yassine 
(manal.yassine@lupm.in2p3.fr).

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.