GRB090227A

This page lists all entries on GRB090227A in GRBweb

Summary Fermi GBM GCN 8917 GCN 8928 GCN 8935

Summary table
Variable Value Source
GRB_name_Fermi GRB090227310
T0 7:25:57 UTC GCN_circulars,Fermi GBM Det
ra 3.3000° Fermi_GBM
decl -43.0000° Fermi_GBM
pos_error 2.62e+00° Fermi_GBM
T90 16.189 s Fermi_GBM
T90_error 0.831 s Fermi_GBM
T90_start 7:25:57.006 UTC Fermi_GBM
fluence 2.86e-06 erg/cm² Fermi_GBM
fluence_error 2.08e-08 erg/cm² Fermi_GBM
T100 16.195 s
GBM_located True
mjd 54889.3096875 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB090227310
trigger_name bn090227310
ra 3.3000°
decl -43.0000°
pos_error 2.62e+00°
datum 2009-02-27
t_trigger 7:25:57.003 UTC
T90 16.189 s
T90_error 0.831 s
T90_start 7:25:57.006 UTC
fluence 2.86e-06 erg/cm²
fluence_error 2.08e-08 erg/cm²
flux_1024 3.94e+00 erg/cm²/s
flux_1024_error 2.67e-01 erg/cm²/s
flux_1024_time 1.92e+00 erg/cm²/s
flux_64 6.67e+00 erg/cm²/s
flux_64_error 1.21e+00 erg/cm²/s
GCN 8917 table
GRB_name GRB090227A
GCN_number 8917
Detection_method Fermi GBM Det
t_trigger 7:25:57 UTC
ra 3.2000°
decl -43.1000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8917 SUBJECT: GRB 090227: Fermi GBM detection DATE: 09/02/27 19:20:13 GMT FROM: Elisabetta Bissaldi at MPE E. Bissaldi (MPE) reports on behalf of the Fermi GBM Team: "At 07:25:57.00 UT on 27 February 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090227 (trigger 257412359 / 090227310). The on-ground calculated location, using the GBM trigger data, is RA = 3.2, DEC = -43.1 (J2000 degrees, equivalent to 00h 13m, -43d 06'), 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 21 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve shows one main FRED-like pulse with substructure. Emission continues to at least 80 seconds. T90 (8-1000 keV) is about 50 s and T50 (8-1000 keV) is about 20 s. The time-averaged spectrum from T0 to T0+16.3 s is adequately fit by a power law function with an exponential high energy cutoff. The power law index is -0.91 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 1355 +/- 259 keV (chi squared 748 for 729 d.o.f.). The event fluence (8-1000 keV) in this time interval is (9.0 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.9 s in the 8-1000 keV band is 4.57 +/- 0.13 ph/s/cm^2. A Band function fits the spectrum equally well (chi squared 748 for 728 d.o.f.) with Epeak = 1357 +/- 284 keV, alpha = -0.92 +/- 0.06 and beta = -3.6 +/- 2.9. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 8928 table
GRB_name GRB090227A
GCN_number 8928
Detection_method Konus-Wind Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8928 SUBJECT: Konus-RF catches first GRB and SGR bursts DATE: 09/03/04 15:01:46 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, V. Il'inskii, P. Oleynik, M. Ulanov, D. Svinkin, on behalf of the Konus-RF and Konus-Wind teams, report: At 07:25:57 UT on February 27, 2009 the KONUS-RF gamma-ray spectrometer detected its first gamma-ray burst, GRB 090227A (Fermi/GBM trigger 257412359 / 090227310: Bissaldi GCN 8917). That day at 13:43:36 UT the instrument detected a bright short soft burst from the AXP/SGR 1E1547.0-5408. Both bursts also triggered Konus-Wind. The Konus-RF gamma-ray spectrometer is an instrument of the CORONAS-PHOTON solar space observatory that was launched on January 30, 2009 into a low-Earth low-eccentricity, high-inclination orbit (altitude 547-592 km, inclination 82.5 deg). CORONAS-PHOTON is a 3-axis stabilized, Sun-pointing spacecraft. Konus-RF has been successfully operating since February 19. The Konus-RF experiment is aimed at studying of temporal and spectral characteristics of solar flares, gamma-ray bursts, and SGR bursts in a wide energy range from 10 keV to 10 MeV. It consists of two identical omnidirectional detectors one of which points toward the Sun thereby observing the solar hemisphere, and the other observes the antisolar hemisphere. Thus, the instrument provides continuous monitoring of the unocculted sky. However, the usable exposure time is severely limited by passage through the radiation belts at high latitudes and the South Atlantic Anomaly. Each detector employs NaI(Tl) crystal, 127 mm in diameter and 76.2 mm in height, supplied with a beryllium entrance window. The Konus-RF instrument is an advanced modification of the Russian-American Konus-Wind spectrometer. More details can be found at http://www.astro.mephi.ru/coronos-photon_conusrf_e.htm The Konus-RF and Konus-Wind light curves of the SGR burst 090227 are available at http://www.ioffe.ru/LEA/SGRs/090227_T49414/
GCN 8935 table
GRB_name GRB090227A
GCN_number 8935
Detection_method Suzaku WAM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8935 SUBJECT: GRB 090227A: Suzaku WAM observation of the prompt emission DATE: 09/03/05 14:12:32 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 090227A (Bissaldi et al., GCN 8917) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 07:25:56.862 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0-1s, ending at T0+17s with a duration (T90) of about 12.7 seconds. The fluence in 100 - 1000 keV was 8.00(-1.41, +0.36) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0+1s was 2.27(-1.00, +0.14) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-1s to T0+17s is fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 1.16(-0.28, +0.22), and Epeak 1328(-465, +951) keV (chi^2/d.o.f. = 6.73/14). 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