[vsnet-grb-info 7333] GRB 090207 - Fermi GBM Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8899
SUBJECT: GRB 090207 - Fermi GBM Observations
DATE:    09/02/10 18:35:46 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat at nasa.gov>

P. N. Bhat (UAH) 
reports on behalf of the Fermi GBM Team:

"At 18:39:10.84 UT on 07 February 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090207 (trigger 255724752 / 090207777).

The on-ground calculated location, using the GBM trigger
data, is RA = 244.66, DEC = +36.81 (J2000 degrees,
equivalent to 16 h 19 m, 36 d 49'), with an uncertainty
of 3 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 45 degrees.

The GBM light curve shows a typical fast rise and a slow decay
pulse with a duration (T90) of about 10 s (8-1000 keV).
The time-averaged spectrum from T0-2.048 s to T0+15.36 s is
well fit by a power law function. The power law index is -1.59 +/- 0.04

(chi squared 490 for 508 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(4.01 +/- 0.09)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 in the 8-1000 keV band
is 1.88 +/- 0.04 ph/s/cm^2.

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