[vsnet-grb-info 7129] GRB 081204C: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8710
SUBJECT: GRB 081204C: Fermi GBM detection
DATE:    08/12/22 22:37:27 GMT
FROM:    Valerie Connaughton at MSFC  <valerie at nasa.gov>

Valerie Connaughton (UAH)
reports on behalf of the Fermi GBM Team:

"At 00:05:24.24 UT on 04 December 2008, the Fermi Gamma-Ray Burst
Monitor triggered and located GRB 081204C
(trigger 250041925 / 081204004).

The on-ground calculated location, using the GBM trigger
data, is RA = 61.9, DEC = -61.5 (J2000 degrees,
equivalent to 04h 08m, -61d 30'), with an uncertainty
of 4.0 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 56 degrees.


The GBM light curve consists of a single weak pulse
with a duration (T90) of about 4.7 s (8-1000 keV).
The time-averaged spectrum from T0-0.8 s to T0+2.3 s is
adequately fit by a Power Law of index around -1.4.
Although the Band function is preferred statistically,
the burst is too weak to constrain its parameters.

The event fluence (8 -- 1000 keV) in this time interval
using a simple power-law fit is (1.48 +/- 0.3)E-06 erg/cm^2.
The 1-sec peak photon flux measured starting from T0 s
in the 8 - 1000 keV band is 7.2 +/- 0.3 ph/s/cm^2.

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