GRB090401B

This page lists all entries on GRB090401B in GRBweb

Summary IPN Swift GCN 9066 GCN 9067 GCN 9068 GCN 9069 GCN 9070 GCN 9073 GCN 9074 GCN 9075 GCN 9076 GCN 9078 GCN 9079 GCN 9080 GCN 9081 GCN 9082 GCN 9083 GCN 9084

Summary table
Variable Value Source
T0 8:35:22.964 UTC GCN_circulars,Konus-Wind Det
ra 95.0880° Swift
decl -8.9721° Swift
pos_error 6.47e-05° Swift
T90 183.0 s Swift
T90_start 8:35:25 UTC Swift
fluence 1.00e-05 erg/cm² Swift
T100 185.036 s
GBM_located False
mjd 54922.357904675926 GCN_circulars,Konus-Wind Det
IPN table
GRB_name GRB090401B
ra 95.1000°
decl -8.9667°
pos_error 5.00e-02°
Swift table
GRB_name GRB090401B
t_trigger 8:35:25 UTC
ra 95.0880°
decl -8.9721°
pos_error 6.47e-05°
T90 183.0 s
fluence 1.00e-05 erg/cm²
GCN 9066 table
GRB_name GRB090401B
GCN_number 9066
Detection_method Swift Det
t_trigger 8:35:25 UTC
ra 95.1010°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9066 SUBJECT: GRB 090401B: Swift detection of a burst DATE: 09/04/01 09:02:29 GMT FROM: David Palmer at LANL P. Schady (MSSL-UCL), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), O. Godet (U Leicester), H. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB), P. T. O'Brien (U Leicester), S. R. Oates (UCL-MSSL), J. P. Osborne (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC), P. Romano (INAF-IASFPA), B. A. Rowlinson (U Leicester) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 08:35:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090401B (trigger=348152). The BAT on-board calculated location is RA, Dec 95.101d, -8.963d which is RA(J2000) = 06h 20m 24s Dec(J2000) = -8d 57' 47" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows at least four overlapping peaks with a total duration of ~20 seconds. The peak count rate was ~55,000 counts/sec (15-350 keV), at ~8 sec after the trigger. The XRT began observing the field at 08:36:37.9 UT, 73.2 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 95.0889, -8.9734 which is equivalent to: RA(J2000) = 06h 20m 21.33s Dec(J2000) = -08d 58' 24.2" with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 57 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the White filter starting 81 seconds after the BAT trigger. No credible afterglow candidate has been found in the automatic analysis. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag, although we note that there are two bright known sources within the XRT error circle that may be confusing source detection. One of these sources appears to be brighter and slightly offset from the DSS position, suggesting the possible detection of the optical afterglow. However, we shall need more data to check for any variability. The coverage of the XRT error circle by the 8'x8' region for the list of sources generated on-board is uncertain because the large number of sources filled the available telemetry. No correction has been made for the expected extinction corresponding to E(B-V) of 0.67. Burst Advocate for this burst is P. Schady (ps AT mssl.ucl.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN 9067 table
GRB_name GRB090401B
GCN_number 9067
Detection_method Swift-UVOT Det
ra 95.0880°
decl -8.9721°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9067 SUBJECT: Swift/UVOT detection of GRB090401B DATE: 09/04/01 09:39:08 GMT FROM: Patricia Schady at MSSL/Swift P.Schady (MSSL-UCL) and S.R.Oates report on behalf of the Swift/UVOT team Following from the tentative UVOT afterglow detection of GRB090401B reported in Schady et al. (GCN 9066), we here report a fading by over two magnitudes between the two UVOT white finding charts, taken 792s apart at the following position RA (J2000) = 06:20:21.11 (95.08775deg) Dec (J2000) = -08:58:19.5 (-8.97199deg) with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence), suggesting this to be the optical afterglow of GRB090401B. This position falls on a known source, making absolute magnitudes and a precise localisation difficult at this stage, and further data will be required in order to carry out source subtraction. The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.67 in the direction of the burst (Schlegel et al. 1998). All photometry is on the UVOT photometry system described in Poole et al. (2008, MNRAS, 383, 627).
GCN 9068 table
GRB_name GRB090401B
GCN_number 9068
Detection_method Swift-BAT Det
ra 95.0950°
decl -8.9630°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9068 SUBJECT: GRB 090401B: Swift-BAT refined analysis DATE: 09/04/01 12:38:51 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), P. Schady (MSSL-UCL), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+914 sec from the recent telemetry downlink, we report further analysis of BAT GRB 090401B (trigger #348152) (Schady, et al., GCN Circ. 9066). The BAT ground-calculated position is RA, Dec = 95.095, -8.963 deg, which is RA(J2000) = 06h 20m 22.7s Dec(J2000) = -08d 57' 47.1" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 67%. The mask-weighted light curve shows several FRED-like peaks with the first starting at ~T-0.4 sec. The brightest peak is at ~T+7 sec with a long exponential tail out to ~T+600 sec. T90 (15-350 keV) is 183 +- 39 sec (estimated error including systematics). The time-averaged spectrum from T-0.1 to T+326.1 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.37 +- 0.05. The fluence in the 15-150 keV band is 1.0 +- 0.0 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+6.49 sec in the 15-150 keV band is 23.1 +- 0.5 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/348152/BA/
GCN 9069 table
GRB_name GRB090401B
GCN_number 9069
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9069 SUBJECT: AGILE Gamma-ray detection of GRB 090401B DATE: 09/04/01 13:17:12 GMT FROM: Marco Feroci at IASF/INAF E. Moretti, F. Longo, G. Barbiellini, E. Vallazza (INFN Trieste), A. Giuliani (INAF/IASF Milan), S. Cutini, C. Pittori (ASDC), A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF Milan), E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, L. Pacciani, P. Soffitta, E. Costa, F. Lazzarotto, I. Lapshov, M. Rapisarda (INAF/IASF Rome), A. Pellizzoni, M. Pilia (INAF/OA Cagliari), S. Vercellone (INAF/IASF Palermo), A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi, M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V. Vittorini, A. Argan, A. Trois, G. Piano, S. Sabatini (INAF/IASF Rome), P. Picozza, A. Morselli (INFN Roma-2), M. Prest (Universita' dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), A.Rappoldi, P. Cattaneo (INFN Pavia) and P. Giommi, P. Santolamazza F.Verrecchia (ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report: The gamma ray burst 090401B (Schady et al. GCN 9066 & 9067) occurred in the field of view of AGILE, approximately 41 deg off-axis. This 12-s long event was triggered and localized in one dimension by SuperAGILE. It was detected also by the AGILE/ACS and MCAL, with significant detection above 2.8 MeV. A preliminary analysis of the Gamma-Ray Imaging Detector (GRID) data in temporal and spatial coincidence with the GRB shows a significant excess of gamma-ray events above 30 MeV at the location of the event. A more detailed analysis of the AGILE-GRID data is in progress. More observations of this interesting burst are strongly encouraged. This message may be cited.
GCN 9070 table
GRB_name GRB090401B
GCN_number 9070
Detection_method Swift-XRT Det
ra 95.0877°
decl -8.9724°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9070 SUBJECT: GRB 090401B: Enhanced Swift-XRT position DATE: 09/04/01 13:51:40 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2409 s of XRT Photon Counting mode data and 5 UVOT images for GRB 090401B, 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 = 95.08773, -8.97244 which is equivalent to: RA (J2000): 06h 20m 21.06s Dec (J2000): -08d 58' 20.8" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, arXiv:0812.3662). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 9073 table
GRB_name GRB090401B
GCN_number 9073
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9073 SUBJECT: GRB 090401B: Swift XRT Refined Analysis DATE: 09/04/01 17:41:33 GMT FROM: Antonia Rowlinson at U.of Leicester A. Rowlinson (U. Leicester) and P. Schady (MSSL-UCL) report on behalf of the Swift-XRT team: We have analysed 3.7 ks of XRT data for GRB 090401B (Schady et al. GCN Circ. 9066), from 79 s to 7.2 ks after the BAT trigger. The data comprise 1.3 ks in Windowed Timing (WT) mode and 2.4ks in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 9070). The light curve can be modelled with an initial power-law decay with an index of alpha=1.145 (+/-0.020), followed by a break at T+474 s to an alpha of 1.409 (+0.028, -0.026). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.736 (+/-0.026). The best-fitting absorption column is 3.68 (+/-0.12) x 10^21 cm^-2, in excess of the Galactic value of 2.3 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.13 (+/-0.11) and a best-fitting absorption column of 4.4 (+0.5, -0.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.5 x 10^-11 (8.4 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 1.409, the count rate at T+24 hours will be 0.017 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.7 x 10^-13 (1.4 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00348152. This circular is an official product of the Swift-XRT team. [GCN OPS NOTE(02apr09): Per author's request, the typo in the Subject line of "080401B" was changed to "090401B".]
GCN 9074 table
GRB_name GRB090401B
GCN_number 9074
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9074 SUBJECT: Swift/UVOT observations of GRB090401B DATE: 09/04/01 17:50:53 GMT FROM: Patricia Schady at MSSL/Swift P. Schady (MSSL-UCL) and S.R.Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team: Swift UVOT began settled exposures of GRB090401B (Schady et al, GCN 9066) 82 s after the burst trigger, and detected a bright optical transient at the position reported in by Schady et al. (GCN 9067), consistent with the enhanced XRT error circle (Osborne et al, GCN 9070). The source is detected in the white, v, b and u filter, but not in any of UV filters, placing an upper limit on the redshift of z < 3. We note that the afterglow lies close to a known source, which may be contaminating our phometry. The light curve decays steeply at early times at a rate of alpha_1~1.5, and then breaks at ~T+440s to a slope of alpha_2~0.7. Using 2.5arcsec aperture, the magnitudes and 3 sigma upper limits to our observations our reported below: Filt T_start (s) T_stop (s) Exp (s) Mag/3-sig UL white 82 232 147 16.83+/-0.02 white 874 1024 147 19.14+/-0.08 v 623 1248 78 18.31+/-0.20 v 4753 4953 197 19.10+/-0.25 b 549 1346 58 19.48+/-0.26 b 5573 5773 197 20.39+/-0.28 u 293 543 246 17.99+/-0.07 u 698 1312 58 18.67+/-0.22 uvw1 672 1297 78 > 19.42 uvm2 647 1272 78 > 18.99 uvw2 599 1387 78 > 19.39 The above magnitudes have not been corrected for the Galactic extinction corresponding to E(B-V) = 0.67 (Schlegel et al 1998). The photometry is on the UVOT flight system described in Poole et al (2008, MNRAS, 383,627)
GCN 9075 table
GRB_name GRB090401B
GCN_number 9075
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9075 SUBJECT: GRB 090401B: AGILE refined analysis DATE: 09/04/01 17:52:03 GMT FROM: Sara Cutini at ASDC A.Giuliani (INAF/IASF Milan), S.Cutini, C. Pittori (ASDC) E. Moretti, F.Longo, G.Barbiellini, E.Vallazza (INFN Trieste), M. Marisaldi, A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Galli, (INAF/IASF Bologna), A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF Milan), E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, L. Pacciani, P. Soffitta, E. Costa, F. Lazzarotto, I. Lapshov, M. Rapisarda(INAF/IASF Rome), A. Pellizzoni, M. Pilia (INAF/OA Cagliari), S. Vercellone (INAF/IASF Palermo), M. Tavani, G. Pucella, F. D'Ammando, V.Vittorini, A. Argan, A. Trois, G. Piano, S. Sabatini (INAF/IASF Rome), P. Picozza, A. Morselli (INFN Roma-2), M. Prest (Universita' dell'Insubria), P.Lipari, D. Zanello (INFN Roma-1), A.Rappoldi, P.Cattaneo (INFN Pavia) and P. Giommi, P. Santolamazza, F.Verrecchia (ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report: A more refined analysis of the AGILE-GRID (Gamma-Ray Imaging Detector) data of GRB 090401B (Moretti et al. GCN 9069) confirms the gamma-ray detection of the GRB at energies above 30 MeV with a statistical significance larger than 4 for a 10-second integration after trigger. Fluence estimate for a 10 second integration is 0.038+/-0.011 ph/cm2 (above 30 MeV). The GRB 090401B gamma-ray spectrum appears to be relatively hard. An estimate of fluence in the 500 keV - 10 MeV range, as derived from MCAL data, is (1.6 +/- 0.5)e-5 erg/cm2 in the same time interval. This message may be cited.
GCN 9076 table
GRB_name GRB090401B
GCN_number 9076
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9076 SUBJECT: Swift/UVOT observations of GRB090401B DATE: 09/04/01 18:01:23 GMT FROM: Patricia Schady at MSSL/Swift P. Schady (MSSL-UCL) and S.R.Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team: Swift UVOT began settled exposures of GRB090401B (Schady et al, GCN 9066) 82 s after the burst trigger, and detected a bright optical transient at the position reported in by Schady et al. (GCN 9067), consistent with the enhanced XRT error circle (Osborne et al, GCN 9070). The source is detected in the white, v, b and u filter, but not in any of UV filters, placing an upper limit on the redshift of z < 3. We note that the afterglow lies close to a known source, which may be contaminating our phometry. The light curve decays steeply at early times at a rate of alpha_1~1.5, and then breaks at ~T+440s to a slope of alpha_2~0.7. Using 2.5arcsec aperture, the magnitudes and 3 sigma upper limits to our observations our reported below: Filt T_start (s) T_stop (s) Exp (s) Mag/3-sig UL white 82 232 147 16.83+/-0.02 white 874 1024 147 19.14+/-0.08 v 623 1248 78 18.31+/-0.20 v 4753 4953 197 19.10+/-0.25 b 549 1346 58 19.48+/-0.26 b 5573 5773 197 20.39+/-0.28 u 293 543 246 17.99+/-0.07 u 698 1312 58 18.67+/-0.22 uvw1 672 1297 78 > 19.42 uvm2 647 1272 78 > 18.99 uvw2 599 1387 78 > 19.39 The above magnitudes have not been corrected for the Galactic extinction corresponding to E(B-V) = 0.67 (Schlegel et al 1998). The photometry is on the UVOT flight system described in Poole et al (2008, MNRAS, 383,627)
GCN 9078 table
GRB_name GRB090401B
GCN_number 9078
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9078 SUBJECT: GRB 090401B: NOT optical observations DATE: 09/04/01 22:10:33 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani, J.P.U. Fynbo (DARK/NBI), J. Heidt (Heidelberg), T. Liimets (Tartu Observatory), T. Pursimo (NOT), and P. Jakobsson (Univ. Iceland), report on behalf of a larger collaboration: We observed the optical afterglow of GRB 090401B (Schady et al., GCN 9066; Schady & Oates, GCN 9067), also detected by AGILE (Moretti et al., GCN 9069; Giuliani et al., GCN 9075). Observations were carried out in the R band with the Nordic Optical Telescope, starting on April 1.870 UT, 12.3 hr after the GRB. In a single 300 s exposure, the afterglow is clearly detected, with a magnitude R ~ 22.2 +- 0.1, referred to USNO-B1 stars in the neighbourhood. We acknowledge excellent support from the NOT visiting observers and staff.
GCN 9079 table
GRB_name GRB090401B
GCN_number 9079
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9079 SUBJECT: GRB090401B, RIMOTS optical upper limits DATE: 09/04/02 05:17:04 GMT FROM: Kenta Kono at Miyazaki U K.Kono, K.Noda, E.Sonoda, N.Ohmori, H.hayasi, A.Daikyuji, Y.Nisioka, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB090401B (Swift trigger 348152, GCN 9066, Schady et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 10:47:10 UT, about 1.8 hr after the Swift trigger time. We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, There is no new source at the reported position. (GCN 9068, Stamatikos et al. GCN 9070, Osborne et al. ) the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 11:41:47 11:42:17 1 16.8 11:41:47 12:32:21 43 17.7 ---------------------------------------------------------------
GCN 9080 table
GRB_name GRB090401B
GCN_number 9080
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 9080 SUBJECT: GRB 090401B: Upper limits of MITSuME optical observation DATE: 09/04/02 13:49:37 GMT FROM: Michitoshi Yoshida at Okayama Astrophysical Obs D. Kuroda, M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama, H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 090401B (Schady et al. GCN 9066) with optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. We did not detect the optical afterglow reported by Schady and Oates (GCN 9067; GCN 9074). 3-sigma upper limits to our observation are listed below. We used GSC2.3 catalog for flux calibration. Mid-UT T(s) EXP(s) g' Rc Ic ------------------------------------------------------------- 2009-04-01 10:43:51 7706 660 >18.2 >18.1 >17.6 -------------------------------------------------------------
GCN 9081 table
GRB_name GRB090401B
GCN_number 9081
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9081 SUBJECT: GRB 090401B: VLA radio upper limit DATE: 09/04/02 16:49:43 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We used the Very Large Array to observe the field of view toward GRB 090401B (GCN 9066) at a frequency of 8.46 GHz on 2009 Apr. 02.15 UT. The GRB radio afterglow is undetected at the Swift-UVOT position (GCN 9067). The three-sigma flux density of the GRB afterglow at the Swift UVOT position is 138 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN 9082 table
GRB_name GRB090401B
GCN_number 9082
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9082 SUBJECT: GRB 090401B: Xinglong TNT optical Upper Limit DATE: 09/04/03 09:17:29 GMT FROM: L.P. Xin at NAOC S.M. Hu, L.P. Xin, W.K. Zheng, Y.L. Qiu, J.Y. Wei, j. Wang, J.S. Deng and J.Y. Hu on behalf of EAFON report: We have observed GRB 090401B (Schady et al., GCN 9066; Schady & Oates, GCN 9067, GCN 9074) with Xinglong TNT telescope from Apr.1, 11:25:22(UT), 3.37 hr after the burst. After combined 9*300s R band images, no new source was found in our combined image. The 3 sigma upper limits was obtained to be R=19.9 mag at the mean time of 2.71 hr after the trigger, with the calibration to USNO-B1.0 R2 magnitude. This message may be cited. For more information about Xinglong GRBs Follow-up observations, please visit the website: http://www.xinglong-naoc.org/grb/
GCN 9083 table
GRB_name GRB090401B
GCN_number 9083
Detection_method Konus-Wind Det
t_trigger 8:35:22.964 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 9083 SUBJECT: Konus-Wind observation of GRB 090401B DATE: 09/04/03 11:35:30 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long bright GRB 090401B (Swift-BAT trigger #348152: Schady et al., GCN 9066; Stamatikos et al., GCN 9068) triggered Konus-Wind at T0=30922.964 s UT (08:35:22.964). The burst light curve shows a multipeaked structure with a duration of ~11 s. There is a hint of an extended soft emission. As observed by Konus-Wind the burst had a fluence of 6.25(-0.75, +0.78)x10^-5 erg/cm2, and a 16-ms peak flux measured from T0+6.576 s of 4.63(-0.86, +0.87)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.996 s) is well fitted (in the 20 keV - 10 MeV range) by GRB (Band) model for which: the low-energy photon index alpha = -0.78(-0.09, +0.11), the high energy photon index beta = -2.14(-0.23, +0.15), the peak energy Ep = 409(-60, +66) keV (chi2 = 61.8/85 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB090401_T30922/
GCN 9084 table
GRB_name GRB090401B
GCN_number 9084
Detection_method Suzaku WAM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9084 SUBJECT: GRB 090401B: Suzaku WAM observation of the prompt emission DATE: 09/04/04 07:04:06 GMT FROM: Kazutaka Yamaoka at Aoyama Gakuin U M. Suzuki, M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), N. Kodaka, W. Iwakiri, M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda, K. Morigami, T. Sugasahara (Saitama U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Sugita, K. Yamaoka (Aoyama Gakuin U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.), 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 bright long GRB 090401B (Swift/BAT trigger #348152; Schady et al. GCN 9066; Stamatikos et al., GCN 9068) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 08:35:24.504 UT (=T0). The observed light curve shows a multi-peaked structure lasting from T0+0s to T0+10s with a duration (T90) of about 9 seconds. The fluence in 100 - 1000 keV was 2.56 (-0.11,+0.09) x 10^-5 erg/cm^2. The 1-s peak flux measured from T0+7s was 21.6 (-1.5,+1.3) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0+0s to T0+10s is well fitted by a single power-law with a photon index of 2.22 (-0.09,+0.10) (chi^2/d.o.f = 24.9/25). 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