GCN Circular 9509
Subject
GRB 090610C: Fermi GBM detection
Date
2009-06-12T16:29:53Z (16 years ago)
From
Adam Goldstein at Fermi-GBM/UAH <adam.m.goldstein@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."