TITLE:   GCN CIRCULAR
NUMBER:  45161
SUBJECT: GRB 260714B: Fermi GBM Detection
DATE:    26/07/15 02:59:10 GMT
FROM:    oindabimukherjee@gmail.com

O. Mukherjee (USRA) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 18:23:26.76 UT on 14 July 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260714B (trigger 805746211/260714766).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 166.40, Dec = 46.66 (J2000 degrees, equivalent to
J2000 11h 5m, +46d 39'), with a statistical uncertainty of 4.01 degrees.
(radius, 1-sigma containment, statistical only; there is additionally a
systematic error which we have characterized as a mixture of two Gaussians,
one with a radius of 1.8 degrees (52% contribution) and one with a radius
of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]).

The angle from the Fermi LAT boresight is 56 degrees.

The GBM light curve consists of a single emission episode with multiple peaks, with a duration (T90) of about 12.5 s (50-300 keV). The time-averaged spectrum
from T0+0.002 to T0+18.435 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.14 +/- 0.01 and the cutoff energy,
parameterized as Epeak, is 660 +/- 3 keV.

The event fluence (10-1000 keV) in this time interval is
(2.51 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+5.2 s in the 10-1000 keV band is 17.1 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"