GCN Circular 44253
Subject
GRB 260410A: Fermi-LAT detection
Event
Date
2026-04-10T14:03:21Z (7 hours ago)
From
A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>
Via
Web form
A. Holzmann Airasca (Univ. Trento and INFN Bari), D. Depalo (Politecnico and INFN Bari), S. Lopez (CNRS / IN2P3), R. Gupta (NASA / GSFC) and F. Longo (Univ. and INFN Trieste) report on behalf of the Fermi-LAT team the detection of a likely SHORT GRB:
At 07:03:57.00 UT on April 10th, 2026, Fermi-LAT detected high-energy emission from GRB 260410A, which was also detected by Fermi-GBM (trigger 797497442 / 260410294, GCN #44252).
The best LAT on-ground location is found to be
RA, Dec = 110.67, -20.94 (J2000)
with an error radius of 0.17 deg (90 % containment, statistical error only).
This was 49 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 correlated with the trigger with high significance.
The photon flux above 100 MeV in the time interval 0 - 2 s after the GBM trigger is (1.23 ± 0.38)E-3 ph/cm2/s. The estimated photon index above 100 MeV is -1.84 ± 0.24. The highest-energy photon is a 6.1 GeV event, which is observed 0.37 seconds after the GBM trigger.
The Fermi-LAT point of contact for this burst is Sara Cutini (sara.cutini@pg.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.