| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB090228976 |
|
| T0 |
23:25:01.020 UTC |
GCN_circulars,Fermi GBM Det |
| ra |
357.6000° |
Fermi_GBM |
| decl |
36.7000° |
Fermi_GBM |
| pos_error |
3.19e+00° |
Fermi_GBM |
| T90 |
7.936 s |
Fermi_GBM |
| T90_error |
1.379 s |
Fermi_GBM |
| T90_start |
23:25:01.023 UTC |
Fermi_GBM |
| fluence |
9.64e-07 erg/cm² |
Fermi_GBM |
| fluence_error |
6.58e-08 erg/cm² |
Fermi_GBM |
| T100 |
7.939 s |
|
| GBM_located |
True |
|
| mjd |
54890.97570625 |
GCN_circulars,Fermi GBM Det |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB090228976 |
| trigger_name |
bn090228976 |
| ra |
357.6000° |
| decl |
36.7000° |
| pos_error |
3.19e+00° |
| datum |
2009-02-28 |
| t_trigger |
23:25:01.023 UTC |
| T90 |
7.936 s |
| T90_error |
1.379 s |
| T90_start |
23:25:01.023 UTC |
| fluence |
9.64e-07 erg/cm² |
| fluence_error |
6.58e-08 erg/cm² |
| flux_1024 |
2.28e+00 erg/cm²/s |
| flux_1024_error |
2.38e-01 erg/cm²/s |
| flux_1024_time |
2.69e+00 erg/cm²/s |
| flux_64 |
3.94e+00 erg/cm²/s |
| flux_64_error |
1.21e+00 erg/cm²/s |
| GCN 8927 table |
|---|
| GRB_name |
GRB090228B |
| GCN_number |
8927 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
23:25:01.020 UTC |
| ra |
356.5000° |
| decl |
36.1000° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 8927
SUBJECT: GRB 090228B: Fermi GBM detection
DATE: 09/03/03 23:31:08 GMT
FROM: Vandiver Chaplin at UAH/Fermi-GBM
V.Chaplin (UAH) reports on behalf of the Fermi GBM Team:
"At 23:25:01.02 UT on 28 FEB 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090228B (trigger 257556303 / 090228976).
The on-ground calculated location, using the GBM trigger
data, is RA = 356.5, DEC = +36.1 (J2000 degrees,
equivalent to 23h 44m, +36d 10' ), with an uncertainty
of 1.77 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 20 degrees.
The GBM light curve consists of one main pulse
with a duration (T90) of about 7.232 s (8-1000 keV).
The time-averaged spectrum from T0-1.408 s to T0+5.760 s is
adequately fit by a power law function with an exponential
high energy cutoff. The power law index is -0.6963 +/- 0.293 and
the cutoff energy, parameterized as Epeak, is 147.8 +/- 34.1 keV
(chi squared 221.01 for 235 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(9.9607 +/- 0.22)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.688 s in the 8-1000 keV band
is 2.53 +/- 1.0 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog." |