GRB090902B

This page lists all entries on GRB090902B in GRBweb

Summary Fermi GBM IPN Fermi LAT GCN 9866 GCN 9867 GCN 9868 GCN 9869 GCN 9870 GCN 9871 GCN 9872 GCN 9873 GCN 9874 GCN 9875 GCN 9876 GCN 9877 GCN 9878 GCN 9883 GCN 9889 GCN 9897 GCN 9916

Summary table
Variable Value Source
GRB_name_Fermi GRB090902462
T0 11:05:08 UTC Fermi_LAT
ra 264.9392° Fermi_LAT
decl 27.3242° Fermi_LAT
pos_error 1.39e-04° Fermi_LAT
T90 19.328 s Fermi_GBM
T90_error 0.286 s Fermi_GBM
T90_start 11:05:11.129 UTC Fermi_GBM
fluence 2.22e-04 erg/cm² Fermi_GBM
fluence_error 3.17e-07 erg/cm² Fermi_GBM
redshift 1.8220
T100 22.457 s
GBM_located False
mjd 55076.46189814815 Fermi_LAT
Fermi GBM table
GRB_name_Fermi GRB090902462
trigger_name bn090902462
ra 264.9392°
decl 27.3244°
pos_error 2.47e+00°
datum 2009-09-02
t_trigger 11:05:08.313 UTC
T90 19.328 s
T90_error 0.286 s
T90_start 11:05:11.129 UTC
fluence 2.22e-04 erg/cm²
fluence_error 3.17e-07 erg/cm²
flux_1024 7.69e+01 erg/cm²/s
flux_1024_error 4.42e-01 erg/cm²/s
flux_1024_time 9.09e+00 erg/cm²/s
flux_64 1.00e+02 erg/cm²/s
flux_64_error 1.92e+00 erg/cm²/s
IPN table
GRB_name GRB090902B
ra 265.0000°
decl 27.3333°
pos_error 1.00e-01°
redshift 1.8220
Fermi LAT table
GRB_name_Fermi GRB090902462
GRB_name GRB090902B
MET 273582310.0
datum 2009-09-02
t_trigger 11:05:08 UTC
ra 264.9392°
decl 27.3242°
pos_error 1.39e-04°
GCN 9866 table
GRB_name GRB090902B
GCN_number 9866
Detection_method Fermi GBM Det
t_trigger 11:05:08.310 UTC
ra 264.5000°
decl 26.5000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9866 SUBJECT: GRB 090902B: Fermi GBM detection of a bright burst DATE: 09/09/02 21:19:03 GMT FROM: Elisabetta Bissaldi at MPE Elisabetta Bissaldi (MPE) and Valerie Connaughton (UAH) report on behalf of the Fermi GBM Team: "At 11:05:08.31 UT on 2 September 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090202B (trigger 273582310 / 090902462). The on-ground calculated location, using the GBM trigger data, is RA = 264.5, DEC = 26.5 (J2000 degrees, equivalent to 17h 38m, 26d 30'), with an uncertainty of 1.0 degree (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 52 degrees. Moreover, this burst was bright enough to result in a Fermi spacecraft repointing maneuver. The burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of a bright pulse with a duration of about 21 s. The time-averaged spectrum between 50 keV and 40 MeV from T0 to T0+22 s is well fit by a Band function with Epeak = 775 +/- 11 keV, alpha = -0.696 +/- 0.012 and beta = -3.85 (+0.21/-0.31). The event fluence (50 keV - 10 MeV) in this time interval is (3.74 +/- 0.03)E-04 erg/cm^2. The 1-sec peak photon flux measured starting from T0+14 s in the 50 keV - 10 MeV band is 46.1 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 9867 table
GRB_name GRB090902B
GCN_number 9867
Detection_method Fermi LAT Det
t_trigger 11:05:15 UTC
ra 264.5000°
decl 26.5000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9867 SUBJECT: GRB 090902B: Fermi LAT detection DATE: 09/09/02 22:48:18 GMT FROM: Hiroyasu Tajima at SLAC Francesco de Palma (Universit e INFN Bari), Johan Bregeon (INFN, Pisa) and Hiro Tajima (SLAC) report on behalf of the Fermi LAT team: At 11:05:15 UT on 2 Sep 2009, the Fermi Large Area Telescope (LAT) detected gamma rays from the long GRB 090902B, which was triggered and located by the Fermi Gamma-ray Burst Monitor (GBM) (trigger 273582310/090902462, GCN9866). The angle of the GBM best position (RA, Dec= 264.5, 26.5) with respect to the LAT boresight was 51 degrees at the time of the trigger, which is close the edge of our field of view. The data from the Fermi LAT show a significant increase in the event rate within 1 degree of the GBM location after the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. More than 200 photons above 100 MeV and more than 30 photons above 1 GeV are observed within 100 seconds. The highest energy photon is a 33.4 GeV event which is observed 82 seconds after the GBM trigger. The best LAT on-ground localization is found to be (RA,Dec=265.00, 27.33) with a 90% containment radius of 0.06 deg (statistical; 68% containment radius: 0.04 deg, preliminary systematic error is less than 0.1 deg) which is consistent with the GBM localization. A Swift TOO request has been issued. Further analysis is ongoing. The point of contact for this burst is Francesco de Palma (francesco.depalma@ba.infn.it) The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. This message can be cited.
GCN 9868 table
GRB_name GRB090902B
GCN_number 9868
Detection_method Swift-XRT Other
ra 264.9398°
decl 27.3240°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9868 SUBJECT: GRB 090902B: Swift/XRT Afterglow Candidate DATE: 09/09/03 03:00:57 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. A. Kennea (PSU) and G. Stratta (ASDC) report on behalf of the Swift/XRT team: At 23:36 UT, September 2nd, 2009, Swift began a Target of Opportunity observation of the Fermi GBM/LAT discovered burst GRB 090902B (de Palma et al., GCN #9867, Bissaldi et al., GCN #9866), approximately 12.5 hours after the Fermi detection. In early data we detect an uncatalogued point source at the following location, RA, Dec = 264.93984, 27.32405, which is equivalent to: RA (J2000) = 17h 39m 45.6s Dec (J2000) = +27d 19' 26.6'' with an estimated uncertainty of 4.2 arcseconds radius (90% confidence). This position is 3.2 arcmin from the reported LAT position, inside the LAT error radius. At this time we cannot confirm if the point source is fading. Observations of this field are on-going.
GCN 9869 table
GRB_name GRB090902B
GCN_number 9869
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9869 SUBJECT: GRB090902B: Swift/UVOT observations DATE: 09/09/03 04:57:44 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and M. H. Siegel (PSU) report on behalf of the Swift UVOT team: The Swift/UVOT began observations of the field of GRB090902B approximately 12.5 hours after the Fermi GBM/LAT trigger (de Palma et al., GCN #9867, Bissaldi et al., GCN #9866). Within the initial 4.2" XRT error circle (Kennea et al., GCN #9868) we find a very faint source: Filter T_start(s) T_stop(s) Exp(s) Mag u 273627410 273634846 2691 20.41 +- 0.20 (5.5-sigma) This source does not seem to appear in the DSS; however, its proximity to another DSS source, also within the XRT error circle, makes identifying this source as the afterglow difficult. We await an enhanced XRT position and/or ground-based detection to confirm the nature of this potential afterglow candidate. The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 9870 table
GRB_name GRB090902B
GCN_number 9870
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9870 SUBJECT: GRB 090902B: Optical afterglow candidate DATE: 09/09/03 05:30:08 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, I. K. W. Kleiser, and J. M. Rex (UC Berkeley) report: We imaged the location of the Swift-XRT candidate afterglow (GCN 9868, Kennea et al.) of extremely bright Fermi GRB 090902B (GCN 9866, Bissaldi et al.) with the Nickel 1-meter telescope at Lick Observatory. We marginally detect a faint source in individual 600-second exposures at the western edge of the XRT error circle with a magnitude comparable to the Digitized Sky Survey limit. This is likely the same source observed by the UVOT (GCN 9868, Swenson et al.). We cannot confirm fading behavior at this time, and further observations are encouraged. A finding chart showing the XRT error circle and the putative afterglow is available at the following URL: http://lyra.berkeley.edu/~dperley/090902b/090902b_lick.jpg
GCN 9871 table
GRB_name GRB090902B
GCN_number 9871
Detection_method Swift-XRT Det
ra 264.9386°
decl 27.3245°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9871 SUBJECT: GRB 090902B: Enhanced Swift-XRT position DATE: 09/09/03 06:25:14 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team. Using 2.7 ks of XRT Photon Counting mode data and 2 UVOT images for GRB 090902B, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 264.93859, 27.32448 which is equivalent to: RA (J2000): 17h 39m 45.26s Dec (J2000): +27d 19' 28.1" with an uncertainty of 2.1 arcsec (radius, 90% confidence). Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.
GCN 9872 table
GRB_name GRB090902B
GCN_number 9872
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9872 SUBJECT: GRB 090902B: Fermi LAT and GBM refined analysis. DATE: 09/09/03 07:36:42 GMT FROM: Valerie Connaughton at MSFC F. de Palma (Universit e INFN Bari), E. Bissaldi (MPE), H. Tajima (SLAC), S. Guiriec (UAH), N. Omodei (INFN Pisa), V. Vasileiou (NASA GSFC/UMBC) and V. Connaughton (UAH) report for the Fermi LAT and GBM teams: Further analysis of GRB 090902B (Bissaldi et al. GCN 9866, de Palma et al. GCN 9867, Kennea et al. GCN 9868) reveals it is detected in the Fermi Large Area Telescope (LAT) at least until 300 s after the Fermi Gamma-Ray Burst Monitor (GBM) trigger time, T0=11:05:08.31 UT. Spectral analysis of the main emission episode, from T0 to T0+25 s, shows a deviation from the Band function obtained from fitting GBM data between 50 keV and 40 MeV (GCN 9866). This deviation is apparent both below 50 keV in the GBM and above 100 MeV in the LAT. It is well-fit by a single power-law, with a well-constrained index that is retrieved from a fit of the GBM data alone, the LAT data alone, and when jointly fitting the entire data set. The parameters for this multi-component fit are Band_alpha = 0.61 0.01, Band_beta = 3.87 0.16, Band_EPeak = 798 7 keV, and a power-law index of 1.94 0.01 that shows no evidence for a spectral cut-off below 100 GeV. The fluence between 8 keV and 30 GeV is 4.86 0.06 x 10-4 ergs/cm2. The points of contact for this burst are: Francesco de Palma (francesco.depalma@ba.infn.it) and Elisabetta Bissaldi (ebs@mpe.mpg.de). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. This message can be cited.
GCN 9873 table
GRB_name GRB090902B
GCN_number 9873
Detection_method Swift-XRT Other
redshift 1.8220
Circular_text TITLE: GCN CIRCULAR NUMBER: 9873 SUBJECT: GRB 090902B: Gemini-N absorption redshift DATE: 09/09/03 08:23:17 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara, D. B. Fox (PSU), N. Tanvir (U. Leicester), E. Berger (Harvard U.) report on behalf of a large collaboration. "On 2009 September 3.27 UT we observed the Fermi/LAT GRB 090902B (Bissaldi et al., GCN 9866, de Palma 9867) with the Gemini-N telescope equipped with the GMOS spectrograph. A single object has been found at the position of the Swift/XRT afterglow (Kennea et al. GCN 9868, Perley et al., GCN 9870) in our acquisition image. A pair of 900 sec exposures spectra were obtained with a wavelength coverage of 4500-7500A under good conditions. The spectrum reveals a series of metal absorption features, MgII[2796,2803], MgI[2853],MnII[2606], FeII[2600], MnII[2594], FeII[2586], FeII[2260], SiII[1808], SiII*[1816]. All these features are consistent with a redshift of z = 1.822, which, therefore, we conclude is the redshift of GRB 090902B. We thank the Gemini-N staff for performing this observation, in particular Ricardo Schiavon."
GCN 9874 table
GRB_name GRB090902B
GCN_number 9874
Detection_method correction
ra 264.9392°
decl 27.3242°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9874 SUBJECT: GRB 090902B: GROND NIR Afterglow Observations DATE: 09/09/03 09:14:50 GMT FROM: Thomas Kruehler at MPE/MPI F. Olivares, P. Afonso, J. Greiner (all MPE Garching), S. McBreen (MPE + UCD), T. Kruehler, A. Rau, A. Yoldas, G. Kanbach (all MPE), and S. Klose (TLS Tautenburg) report on behalf of the GROND team: The field of GRB 090902B, (Fermi GBM trigger 273582310/090902462, Bissaldi et al., GCN #9866) which was detected by the LAT (de Palma et al., GCN #9867), was observed simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at LaSilla Observatory (Chile). Observations started at 00:21 UT on September 3, 2009, 13.25 hours after the GRB trigger. They were performed at a seeing of around 2", at an average air mass larger than 2.0 and under variable sky conditions. We detect a NIR source within the Swift/XRT error circle reported by Kennea et al. (GCN #9868) and on the edge of the Swift/XRT enhanced position (Evans et al. GCN #9871), at: RA (J2000) = 17h 39m 45.41s DEC (J2000) = +27d 19' 27.1" with an uncertainty of 0.5" in each coordinate. This position seems consistent with the object reported by Perley et al. (GCN #9870) and is very likely the source reported by Swenson & Siegel (GCN #9869). The source is not in the field of view of the griz channels, so no statement can be made about the optical bands. The afterglow (Cucchiara et al. GCN #9873) has the following preliminary AB magnitude and shows tentative evidence of fading within the observations. midtime J_AB mag ----------------------------------------------- 01:09:31 UT 20.26 +/- 0.07 Calibrations was done against 2MASS catalog stars. No Galactic extinction correction was applied.
GCN 9875 table
GRB_name GRB090902B
GCN_number 9875
Detection_method Swift-UVOT Other
ra 264.9281°
decl 27.3205°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9875 SUBJECT: GRB 090902B: Faulkes Telescope North observations DATE: 09/09/03 10:09:22 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), N.R. Tanvir (U. Leicester), Z. Cano, I. A. Steele, A. Melandri, D. Bersier, S. Kobayashi, C.J. Mottram, C.G. Mundell, R.J. Smith (Liverpool JMU), A. Gomboc (U. Ljubljana), P. O'Brien (U. Leicester) on behalf of a large collaboration report: On 2009 September 03 at 07:50:02 UT we began observing the Fermi GRB 090902B (Bissaldi et al., GCN 9866; de Palma et al. GCN 9867, 9872) with the Faulkes Telescope North using the R filter. Within the Swift UVOT-enhanced XRT error circle (Evans et al. GCN 9871) we clearly detect the afterglow candidate (Swenson et al. GCN 9869, Perley et al. GCN 9870, Cucchiara et al. GCN 9873, Olivares et al. GCN 9874) at the following position (J2000): RA: 17:39:45.35 Dec: +27:19:27.1 with an uncertainty of 0.7". At the mid epoch of 21.01 hours post burst we measure R=21.03 +- 0.11 mag. Calibration was performed with the USNOB-1 star RA=17:39:42.74 Dec=+27:19:13.76 assuming R2=17.46.
GCN 9876 table
GRB_name GRB090902B
GCN_number 9876
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9876 SUBJECT: GRB090902B: Swift XRT refined analysis DATE: 09/09/03 15:30:29 GMT FROM: Giulia Stratta at ASDC G. Stratta, V. D'Elia, M. Perri (ASDC) report on behalf of the Swift XRT team: At 23:36 UT, September 2nd, 2009, Swift began a Target of Opportunity observation of the Fermi GBM/LAT discovered burst GRB 090902B (de Palma et al., GCN 9867, Bissaldi et al., GCN 9866) about 12.5 hours after the trigger. We confirm that the X-ray source reported by Kennea et al. (GCN Circ. 9868) shows a decaying behavior and is likely the afterglow of GRB 090902B. The enhanced XRT position for this burst was given by Evans (GCN. Circ 9871). The X-ray light curve from T+12.53 hr to T+17.38 hr can be fit with a single power-law model with a decay index of -1.3+/-0.9 (90% confidence level). With 4.8 ks of integration time, the X-ray spectrum from T+12.53 hr to T+17.38 hr after the Fermi/GBM trigger can be fit by an absorbed power-law model with a photon index of 2.1 (+0.3,-0.3) and a rest frame column density of (3.4+/-0.9) x 10^22 cm^-2 at z=1.822 (Cucchiara et al., GCN 9873) in addition to the Galactic column density in the direction of the burst (3.88 x 10^20 cm^-2, Kalberla et al. 2005). Errors are at 90% confidence level. The observed 0.3-10.0 keV flux is 3.2 x 10^-12 erg cm^-2 s^-1 which corresponds to an unabsorbed flux of 4.1 x 10^-12 erg cm^-2 s^-1. Providing the source continues to decay at the same rate, we predict an observed flux of about 8.7 x 10^-13 erg cm^-2 s^-1 at T+2 days. This circular is an official product of the Swift-XRT team. [GCN OPS NOTE(03sep09): Per author's request, the missing Cucchiara reference was added.]
GCN 9877 table
GRB_name GRB090902B
GCN_number 9877
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9877 SUBJECT: GRB 090902B: Swift/UVOT refined analysis DATE: 09/09/03 19:55:45 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and G. Stratta (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began observations of the field of GRB 090902B approximately 12.5 hours after the Fermi GBM/LAT trigger (de Palma et al., GCN Circ. 9867; Bissaldi et al., GCN Circ. 9866). We can now confirm the detection of the optical afterglow (Swenson et al., GCN Circ. 9869; Perley et al., GCN Circ. 9870; Cucchiara et al., GCN Circ. 9873; Olivares et al., GCN Circ. 9874; Guidorzi et al., GCN Circ. 9875) coincident with the enhanced Swift-XRT position (Evans, GCN Circ. 9871). We also observe a decay in the optical afterglow. The observed magnitudes using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) are: Filter T_start(s) T_stop(s) Exp(s) Mag u 45096 46188 1075 20.26 0.19 u 50891 58703 3613 20.50 0.11 u 62457 81106 8756 20.85 0.10 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 9878 table
GRB_name GRB090902B
GCN_number 9878
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9878 SUBJECT: GRB 090902B: ROTSE-III Detection of Optical Afterglow DATE: 09/09/03 20:40:17 GMT FROM: Shashi Bhushan Pandey at ROTSE S. B. Pandey, W. Zheng, F. Yuan and C. Akerlof (U Mich), report on behalf of the ROTSE collaboration: ROTSE-IIIa, located at the Siding Spring Observatory Australia, responded ~ 283 sec after the GBM trigger 273582310 (Bissaldi E. & Connaughton V. GCNC 9866). The Set of images starting ~ 1.4 hours after the trigger covered the GRB 090902B location. The OT (Perley et al. GCNC 9870, Kennea & Stratta GCNC 9868) was detected at 15.9+-0.2 mag in the sum of 30x60 sec exposures. The images taken by ROTSE-IIIc (located naer the H.E.S.S. site at Mt. Gamsberg, Namibia) around 6.6 hours after the burst marginally detect the OT, indicating a decay of ~ 2 magnitudes. The unfiltered images were calibrated relative to USNO B1.0. Further analysis is in progress.
GCN 9883 table
GRB_name GRB090902B
GCN_number 9883
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9883 SUBJECT: GRB 090902B: WSRT Radio Observation DATE: 09/09/04 07:17:14 GMT FROM: Alexander van der Horst at NASA/MSFC A.J. van der Horst (NASA/MSFC/ORAU) A.P. Kamble, R.A.M.J. Wijers (U of Amsterdam) and C. Kouveliotou (NASA/MSFC) report on behalf of a large collaboration: "We observed the position of the GRB 090902B afterglow with the Westerbork Synthesis Radio Telescope at 4.8 GHz at September 3 12.72 UT to September 4 0.35 UT, i.e. 1.07 - 1.55 days after the burst (GCN 9866). We detect a radio source at the 4-sigma level with a flux density of 111 +/- 28 microJy at the position of the optical counterpart (GCN 9869, GCN 9874). We would like to thank the WSRT staff for scheduling and obtaining these observations."
GCN 9889 table
GRB_name GRB090902B
GCN_number 9889
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9889 SUBJECT: GRB 090902B: VLA radio detection DATE: 09/09/04 13:23:07 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of a larger collaboration: "We used the Very Large Array (VLA) to observe the field of view towards the GRB 090902B (GCN 9866) at a frequency of 8.46 GHz on 2009 Sep. 03.94 UT. We clearly detect the GRB afterglow at the GROND NIR afterglow position (GCN 9874) at a flux density of 141+/-39 uJy. Further observations are planned. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN 9897 table
GRB_name GRB090902B
GCN_number 9897
Detection_method Suzaku WAM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9897 SUBJECT: GRB 090902B: Suzaku WAM observation of the prompt emission DATE: 09/09/05 04:36:48 GMT FROM: Kazutaka Yamaoka at Aoyama Gakuin U Y. Terada, M. Tashiro, A. Endo, K. Onda, T. Sugasahara, W. Iwakiri (Saitama U.), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji, E. Sonoda, K. Kono, H. Hayashi, K. Noda, Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), N. Vasquez (Tokyo Tech.), Y. Urata (NCU), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report The Fermi detected long GRB 090902B (Bissaldi et al., GCN 9866, de Palma et al. GCN 9867) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 11:05:08.446 UT (=T0). The observed light curve shows a multi-peaked structure lasting from T0-0.5 s to T0+24.5 s with a duration (T90) of about 19 seconds. The fluence in 100 - 1000 keV was 1.45 (-0.04, +0.03)x10^-4 erg/cm^2. The 1-s peak flux measured from T0+14.5 s was 21.3 (-1.3, +0.9) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-0.5 s to T0+24.5 s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha: 0.91 +/- 0.10, and Epeak: 885 (-38, +39) keV (chi^2/d.o.f. = 25.5/24). Due to this GRB brightness, a 3% systematcic error was added for low energy channels. In addition, there might be some calibration uncertainties in fluence because the GRB photons came into the WAM through the base plate of the satellite. All the quoted errors are at 90% confidence level. 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
GCN 9916 table
GRB_name GRB090902B
GCN_number 9916
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9916 SUBJECT: GRB 090902B: Skynet/PROMPT Observations DATE: 09/09/16 20:05:51 GMT FROM: Josh Haislip at U.North Carolina J. Haislip, D. Reichart, K. Ivarsen, A. LaCluyze, A. Foster, J. Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M. Nysewander report: Skynet observed the Fermi/LAT localization of GRB 090902B (de Palma et al., GCN 9867) with four of the 16" PROMPT telescopes at CTIO beginning 13.3 hours after the trigger in BVRI through variable cloud cover. We do not detect the afterglow (Kennea et al., GCN 9868; Swenson & Siegel, GCN 9869). Stacking only images that increase the limiting magnitude yields: mean 1-sig. 1-sig. time 3-sig. sys. stat. since lim. cal. cal. cal. trig. tel. exp. fil. mag. stars unc. unc. (h) (# x s) (mag) (mag) 14.4 PROMPT-4 18 x 80 R 19.8 240 USNO B1 0.185 0.001 14.4 PROMPT-3 18 x 80 B 19.0 100 USNO B1 0.296 0.002 14.4 PROMPT-5 18 x 80 I 19.0 278 USNO B1 0.234 0.001 14.4 PROMPT-2 17 x 80 V 19.0 217 NOMAD 0.255 0.001