TITLE:   GCN CIRCULAR
NUMBER:  23451
SUBJECT: GRB 181125A: Fermi GBM observation
DATE:    18/11/25 19:15:25 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico & INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:


"At 08:54:41.73 UT on 25 November 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 181125A (trigger 564828886 / 181125371),
which was also detected by the Swift-BAT (Sonbas et al. 2018, GCN 23448).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight
at the GBM trigger time is 64 degrees.

The GBM light curve shows a structured emission
with a duration (T90) of about 4 s (50-300 keV).
The time-averaged spectrum from T0-1.8 s to T0+2 s is
adequately fit by a simple power law function
with index -1.8 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(4.3 +/- 0.10)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.15 s in the 10-1000 keV band
is 2.0 +/- 0.2 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."