[vsnet-grb-info 7104] GRB 081217: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8686
SUBJECT: GRB 081217: Fermi GBM detection
DATE:    08/12/19 22:33:44 GMT
FROM:    Colleen A. Wilson at NASA/MSFC/NSSTC  <colleen.wilson at nasa.gov>

Colleen A. Wilson-Hodge (NASA/MSFC)
reports on behalf of the Fermi GBM Team:

"At 23:34:49.01 UT on 17 December 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081217 (trigger 251249690 / 081217983).

The on-ground calculated location, using the GBM trigger data, is
RA = 116.7, DEC = +26.7 (J2000 degrees, equivalent to 07 h 47 m, 26 d 44'),
with an uncertainty of 2.0 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 54 degrees.

The GBM light curve consists of a broad structured peak with a duration
(T90) of about 39 s (8-1000 keV). The time-averaged spectrum from T0 to
T0+18.432 s is adequately fit by a Band function with
Epeak = 167 +/- 11 keV, alpha = -0.61 +/- 0.09, and beta = -2.7 +/- 0.6.
 
The event fluence (8-1000 keV) in this time interval is
(1.0 +/- 0.07)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 in the 8-1000 keV band is 4.0 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."