GRB090131A

This page lists all entries on GRB090131A in GRBweb

Summary Fermi GBM GCN 8876 GCN 8882

Summary table
Variable Value Source
GRB_name_Fermi GRB090131090
T0 2:09:21.149 UTC Fermi_GBM
ra 352.3000° Fermi_GBM
decl 21.2000° Fermi_GBM
pos_error 2.67e+00° Fermi_GBM
T90 35.073 s Fermi_GBM
T90_error 1.056 s Fermi_GBM
T90_start 2:09:24.221 UTC Fermi_GBM
fluence 1.75e-05 erg/cm² Fermi_GBM
fluence_error 6.57e-08 erg/cm² Fermi_GBM
T100 38.145 s
GBM_located True
mjd 54862.08982811343 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB090131090
trigger_name bn090131090
ra 352.3000°
decl 21.2000°
pos_error 2.67e+00°
datum 2009-01-31
t_trigger 2:09:21.149 UTC
T90 35.073 s
T90_error 1.056 s
T90_start 2:09:24.221 UTC
fluence 1.75e-05 erg/cm²
fluence_error 6.57e-08 erg/cm²
flux_1024 4.03e+01 erg/cm²/s
flux_1024_error 4.19e-01 erg/cm²/s
flux_1024_time 6.46e+00 erg/cm²/s
flux_64 5.94e+01 erg/cm²/s
flux_64_error 1.95e+00 erg/cm²/s
GCN 8876 table
GRB_name GRB090131A
GCN_number 8876
Detection_method Fermi GBM Det
t_trigger 2:09:21.150 UTC
ra 353.0000°
decl 16.4000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8876 SUBJECT: GRB 090131: Fermi GBM detection DATE: 09/02/03 03:23:47 GMT FROM: Adam Goldstein at Fermi-GBM/UAH A. Goldstein (UAH) and A.J. van der Horst (NASA/MSFC/ORAU) report on behalf of the Fermi GBM Team: "At 02:09:21.15 UT on 31 January 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090131 (trigger 255060563 / 090131090). The on-ground calculated location, using the GBM trigger data, is RA = 353.0, DEC = +16.4 (J2000 degrees, equivalent to 23h 32m, 16d 26'), with a statistical uncertainty of less than 1 degree (radius, 1-sigma containment) and an additional systematic error which is currently estimated to be 2 to 3 degrees. The angle from the Fermi LAT boresight is 40 degrees. The GBM light curve consists of two emission pulses, each with substructure and separated by a period of no significant emission above background. The total duration (T90) is about 36.4 s (8-1000 keV). The time-averaged spectrum from T0+0.0 s to T0+42.2 s is best fit by a Band function with Epeak = 58.4 +/- 3.9 keV, alpha = -1.27 +/- 0.07, and beta = -2.26 +/- 0.05 (chi-square 597.4 for 453 d.o.f.). The event fluence (8-1000 keV) in this time interval is (2.23 +/- 0.17)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+6.4 s in the 8-1000 keV band is 47.9 +/- 10.0 ph/s/cm^2. The spectral and temporal analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 8882 table
GRB_name GRB090131A
GCN_number 8882
Detection_method Suzaku WAM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8882 SUBJECT: GRB 090131: Suzaku WAM observation of the prompt emission DATE: 09/02/05 01:05:13 GMT FROM: Yoshitaka Hanabata at Hiroshima U Y. Hanabata, Y. Fukazawa, T. Takahashi, T. Uehara, C. Kira (Hiroshima U.), Y. Terada, M. Tashiro, Y. Urata, A. Endo, K. Onda, N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.), M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), Y.E. Nakagawa, T. Tamagawa (RIKEN), E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono, H. Hayashi (Univ. of Miyazaki), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech), on behalf of the Suzaku WAM team, report: The long GRB 090131 (Goldstein et al., GCN 8876) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2009-01-31 02:09:24.187 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0-5s, ending at T0+46s with a duration (T90) of about 32.6 seconds. The fluence in 100 - 1000 keV was 9.95(-0.59, +0.57) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0+19s was 5.01(-0.39, +0.35) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-5s to T0+46s is fitted by a single power-law with a photon index of 2.29(-0.15, +0.17) (chi^2/d.o.f = 11.4/13). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html