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 8551

GRB 081120: Fermi GBM detection
2008-11-25T17:00:02Z (15 years ago)
Elisabetta Bissaldi at MPE <>
Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team:

"At 14:49:34.57 UT on 20 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081120 (trigger 248885375 / 081120618).
The on-ground calculated location, using the GBM trigger
data, is RA = 205.4, Dec = -9.1 (J2000 degrees,
equivalent to 13h 42m, -09d 06'), with an uncertainty
of 6 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 84 degrees.

The GRB light curve consists of two peaks and has a
duration (T90) of about 12 s (8-1000 keV).
The time-averaged spectrum from T0-3.072 s to T0+6.144 s
is best fit by a Band function with Epeak = 44 +/- 5 keV,
alpha = 0.4 +/- 0.5 and beta = -2.18 +/- 0.10
(chi squared 367 for 353 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(2.7 +/- 0.9)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.048 s in the 8-1000 keV band
is 5.1 +/- 1.6 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