[vsnet-grb-info 20132] GRB 171210A: Fermi-LAT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22228
SUBJECT: GRB 171210A: Fermi-LAT detection
DATE:    17/12/10 17:48:25 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi at uibk.ac.at>

E. Bissaldi (Politecnico & INFN Bari), F. Longo (Univ & INFN Trieste) 
and D. Kocevski (MSFC) report on behalf of the Fermi-LAT team:

"At 11:49:15.26 UT on December 10, 2017 Fermi-LAT detected high-energy emission from GRB 171210A, which was also detected by Fermi-GBM (trigger 534599360 / 171210493).

The best LAT on-ground location is found to be

RA, Dec = 335.29, 24.44 (J2000)

with an error radius of 0.15 deg (90 % containment, statistical error only). 

This was 50 deg from the LAT boresight at the time of the trigger and triggered an autonomous repoint of the spacecraft.

The data from the Fermi-LAT show a significant increase in the event rate that is spatially correlated with the trigger with high significance. 

The highest-energy photon is a 12 GeV event which is observed 1400 seconds after the GBM trigger.

A Swift ToO has been requested for this burst.

The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (Elisabetta.Bissaldi at ba.infn.it).

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."