Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 8715

GRB 081222: Fermi GBM observation
2008-12-23T16:28:19Z (15 years ago)
Elisabetta Bissaldi at MPE <>
E.Bissaldi (MPE) and S. McBreen (UCD/MPE)
report on behalf of the Fermi GBM Team: 

"At 04:54:00.25 UT on 22 December 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081222 (trigger 251614441 / 081222204),
which was also detected by the Swift-BAT (Grupe et al., GCN Circular 8691
and Fenimore et al., GCN Circular 8709).
The angle from the Fermi LAT boresight is 50 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of a main pulse with a
duration (T90) of about 30 s (8-1000 keV) and T50
of about 10 s (8-1000 keV). 

The time-averaged spectrum from T0 to T0+11.52 s is 
best fit by a Band function with Epeak = 134 +/- 9,
alpha = -0.55 +/- 0.07 and beta  = -2.10 +/- 0.06.

The event fluence (8-1000 keV) in this time interval is 
(1.35 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux 
measured starting from T0+3.3 s in the 8-1000 keV band
is 14.8 +/- 1.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."
Looking for U.S. government information and services? Visit