| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB090809978 |
|
| T0 |
23:28:14.610 UTC |
GCN_circulars,Fermi GBM Det |
| ra |
95.2500° |
Fermi_GBM |
| decl |
0.1600° |
Fermi_GBM |
| pos_error |
2.51e+00° |
Fermi_GBM |
| T90 |
11.008 s |
Fermi_GBM |
| T90_error |
0.32 s |
Fermi_GBM |
| T90_start |
23:28:15.699 UTC |
Fermi_GBM |
| fluence |
2.16e-05 erg/cm² |
Fermi_GBM |
| fluence_error |
1.28e-07 erg/cm² |
Fermi_GBM |
| T100 |
12.097 s |
|
| GBM_located |
True |
|
| mjd |
55052.977946875 |
GCN_circulars,Fermi GBM Det |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB090809978 |
| trigger_name |
bn090809978 |
| ra |
95.2500° |
| decl |
0.1600° |
| pos_error |
2.51e+00° |
| datum |
2009-08-09 |
| t_trigger |
23:28:14.611 UTC |
| T90 |
11.008 s |
| T90_error |
0.32 s |
| T90_start |
23:28:15.699 UTC |
| fluence |
2.16e-05 erg/cm² |
| fluence_error |
1.28e-07 erg/cm² |
| flux_1024 |
2.30e+01 erg/cm²/s |
| flux_1024_error |
2.92e-01 erg/cm²/s |
| flux_1024_time |
2.75e+00 erg/cm²/s |
| flux_64 |
2.49e+01 erg/cm²/s |
| flux_64_error |
1.16e+00 erg/cm²/s |
| GCN 9760 table |
|---|
| GRB_name |
GRB090809B |
| GCN_number |
9760 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
23:28:14.610 UTC |
| ra |
95.3000° |
| decl |
0.1000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 9760
SUBJECT: GRB 090809B: Fermi GBM detection
DATE: 09/08/10 15:22:19 GMT
FROM: Alexander van der Horst at NASA/MSFC
A.J. van der Horst (NASA/MSFC/ORAU) reports on behalf of the Fermi GBM
Team:
"At 23:28:14.61 UT on 9 August 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090809B (trigger 271553296 / 090809978).
The on-ground calculated location, using the GBM trigger data, is
RA = 95.3, DEC = 0.1 (J2000 degrees, equivalent to 6h21m, +0d08'),
with an uncertainty of 1.2 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 81 degrees.
The GBM light curve consists of a single pulse with a duration (T90)
of about 15 s (8-1000 keV).
The time-averaged spectrum from T0 to T0+14.3 s is best fit by a Band
function with Epeak = 198 +/- 13 keV, alpha = -0.85 +/- 0.04, and
beta = -2.02 +/- 0.06 (chi squared 552 for 484 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(2.26 +/- 0.03)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.1 s in the 8-1000 keV band is 23.6 +/- 0.5 ph/s/cm^2.
The temporal and spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|