GCN Circular 37478

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

"At 01:46:40.59 UT on 12 September 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240912A (trigger 747798405/240912074).
which was also detected by Swift BAT and XRT (P. A. Evans et al. 2024, GCN 37466
Not found
 
 
), INTEGRAL SPI ACS (D. Pawar 2024, GCN 37473
Not found
 
 
), OSIRIS+/GTC (A. de Ugarte Postigo et al. 2024, GCN 37469
Not found
 
 
), and NOT (J. An et al. 2024, GCN 37471
Not found
 
 
).
The Fermi GBM on-ground location is consistent with the Swift BAT/XRT position.

The angle from the Fermi LAT boresight is 71 degrees.

The GBM light curve single emission episode with a duration (T90)
of about 88.6 s (50-300 keV). The time-averaged spectrum
from T0+0 to T0+124.930 s is best fit by
a Band function
with Epeak = 147 +/- 7 keV, alpha = -1.31 +/- 0.02,
and beta = -2.21 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(8.953 +/- 0.089)E-05 erg/cm^2. The 1.024-s peak photon flux measured
starting from T0+60.2 s in the 10-1000 keV band is 26.43 +/- 0.4 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/"