TITLE:   GCN CIRCULAR
NUMBER:  39290
SUBJECT: GRB 250206A: Fermi GBM Observation
DATE:    25/02/11 20:44:49 GMT
FROM:    oindabimukherjee@gmail.com

O. Mukherjee (USRA) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 19:51:31.93 UT on 06 February 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250206A (trigger 760564296/250206827).
which was also detected by Fermi-LAT (Gupta et al. 2025, GCN 39233) and Konus-Wind (Ridnaia et al. 2025, GCN 39283).
The Fermi GBM on-ground location is consistent with the Fermi-LAT position.

The angle from the Fermi LAT boresight is 33 degrees.

The GBM light curve consists of a multipeaked emission episode followed by a single peaked emission episode with a duration (T90)
of about 64.3 s (50-300 keV). The time-averaged spectrum
from T0-2.0 to T0+79.9 s is best fit by
a Band function with Epeak = 187 +/- 8 keV,
alpha = -0.73 +/- 0.04, and beta = -2.6 +/- 0.2.

The event fluence (10-1000 keV) in this time interval is
(2.66 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.7 s in the 10-1000 keV band is 10.4 +/- 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/"