[vsnet-grb-info 7345] GRB 090219: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8911
SUBJECT: GRB 090219: Fermi GBM detection
DATE:    09/02/20 17:22:18 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat at nasa.gov>

P. N. Bhat (UA Huntsville)
report on behalf of the Fermi GBM Team:

"At 01:46:18.15 UT on 19th February, 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090219 (trigger 256700780 / 090219074).

The on-ground calculated location, using the GBM trigger
data, is RA = 16.4 d, DEC = +60.2 d (J2000 degrees,
equivalent to 1 h 5.6 m, 60 d 12'), with an uncertainty
of 7 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 137 degrees.

The GBM light curve consists of 2 narrow closely spaced
pulses with a duration (T90) of about 0.5 s (8-1000 keV).
The time-averaged spectrum from T0-0.18 s to T0+0.46 s is
adequately fit by a simple power law function with index -1.43 +/- 0.05
(chi squared 385 for 366 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(8.0 +/- 0.4)E-07 erg/cm^2. The X-sec peak photon flux measured
starting from T0-0.18 s in the 8-1000 keV band
is 7.7 +/- 0.4 ph/s/cm^2.

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