[vsnet-grb-info 7966] GRB 090610C: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9509
SUBJECT: GRB 090610C: Fermi GBM detection
DATE:    09/06/12 16:29:53 GMT
FROM:    Adam Goldstein at Fermi-GBM/UAH  <adam.m.goldstein at msfc.nasa.gov>

A. Goldstein (UAH) reports on behalf of the Fermi GBM Team: 

"At 21:12:07.73 UT on 10 June 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090610C (trigger 266361129 / 090610883).

The on-ground calculated location, using the GBM trigger 
data, is RA = 70.4, DEC = +30.3 (J2000 degrees, 
equivalent to 04h 42m, 30d 18'), with an uncertainty 
of 8.2 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 104 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 18.1 s (8-1000 keV). 
The time-averaged spectrum from T0-4.1 s to T0+8.2 s is 
best fit by a simple power law function with index -1.62 +/- 0.08
(chi squared 341.6 for 362 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(8.54 +/- 0.38)E-07 erg/cm^2. The 1-sec peak photon flux 
measured starting from T0-0.51 s in the 8-1000 keV band 
is 1.12 +/- 0.11 ph/s/cm^2.

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