[vsnet-grb-info 7868] GRB 090519B: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9412
SUBJECT: GRB 090519B: Fermi GBM detection
DATE:    09/05/20 15:32:50 GMT
FROM:    Andreas von Kienlin at MPE  <azk at mpe.mpg.de>

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: 

"At 11:05:27.54 UT on 19 May 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090519B (trigger 264423929 / 090519462).
The on-ground calculated location, using the GBM trigger 
data, is RA = 105.9, DEC = -56.7 (J2000 degrees, 
equivalent to 07h 04m, 56d 42'), with an uncertainty 
of 3.9 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 18 degrees.

The GBM light curve shows a single peak lasting 
about 4 seconds superimposed on a lower-level continuum.
The burst duration (T90) is about 87 s (8-1000 keV).
The time-averaged spectrum from T0-2.432 s to T0+1.152 s is 
well fit by a simple power law function with index -1.63 +/- 0.05 
(chi squared 822 for 720 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(1.40 +/- 0.01)E-06 erg/cm^2. The 1-sec peak photon flux measured 
starting from T0-0.640 s in the 8-1000 keV band 
is 5.02 +/- 0.14  ph/s/cm^2.

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