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 11952

GRB 110420B: Fermi GBM observation
2011-04-21T13:55:31Z (13 years ago)
Lin Lin at UAH/NAOC <>
Lin Lin (UAH)
reports on behalf of the Fermi GBM Team:

"At 22:42:11.73 UT on 20 April 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110420B (trigger 325032133 / 110420946).

This burst was also detected by the Swift/BAT
(Sbarufatti et al. 2011, GCN 11944).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 123 degrees.

The GBM light curve shows a fast rise slow decay peak,
with a duration (T90) of about 0.048 s (50-300 keV).
The time-averaged spectrum from T0-0.024 s to T0+0.040 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.12 +/- 0.31 and
the cutoff energy, parameterized as Epeak, is 296.8 +/- 58.7 keV.

The event fluence (10-1000 keV) in this time interval is
(2.65 +/- 0.36)E-7 erg/cm^2. The 0.008-sec peak photon flux measured
starting from T0-0.016 s in the 10-1000 keV band
is 44.1 +/- 6.1 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