GRB 240625A

The Fermi GBM team reports the detection of a likely SHORT GRB

At 07:32:40.63 UT on 25 June 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240625A (trigger 740993565/240625314).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 118.74, Dec = -4.94 (J2000 degrees, equivalent to J2000 7h 54m, -4d 56'),
with a statistical uncertainty of 9.43 degrees.

The angle from the Fermi LAT boresight is 66 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240625314/quicklook/glg_skymap_all_bn240625314.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240625314/quicklook/glg_healpix_all_bn240625314.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240625314/quicklook/glg_lc_medres34_bn240625314.gif

C. de Barra (UCD) and C. Meegan (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

At 07:32:40.63 UT on 25 June 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240625A (trigger 740993565/240625314). The Final Real-time Localization was reported previously (Fermi GBM Team 2024, GCN 36758
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 ).

The angle from the Fermi LAT boresight is 66 degrees.

The GBM light curve consists of a single short emission episode with a duration (T90)
of about 0.15 s (50-300 keV). The time-averaged spectrum from T0+0 to T0+0.192 s is
best fit by a power law function with an exponential high-energy cutoff.
The power law index is -0.94 +/- 0.08 and the cutoff energy, parameterized as Epeak, is 113 +/- 6 keV.
 
The spectrum is equally well fit by a Band function with Epeak= 107 +/- 9 keV, alpha = -0.88 +/- 0.10 and beta = -3.00 +/- 0.46.

The event fluence (10-1000 keV) in this time interval is (7.5 +/- 0.3)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0.0 s in the 10-1000 keV band is 109 +/- 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/"