GRB081121A

This page lists all entries on GRB081121A in GRBweb

Summary Fermi GBM IPN Swift GCN 8536 GCN 8537 GCN 8538 GCN 8539 GCN 8540 GCN 8541 GCN 8542 GCN 8543 GCN 8544 GCN 8546 GCN 8547 GCN 8548 GCN 8643

Summary table
Variable Value Source
GRB_name_Fermi GRB081121858
T0 20:35:27.500 UTC GCN_circulars,Fermi GBM Det
ra 89.2756° Swift
decl -60.6028° Swift
pos_error 7.77e-05° Swift
T90 41.985 s Fermi_GBM
T90_error 8.51 s Fermi_GBM
T90_start 20:35:29.290 UTC Fermi_GBM
fluence 1.53e-05 erg/cm² Fermi_GBM
fluence_error 2.20e-07 erg/cm² Fermi_GBM
redshift 2.5120
T100 43.775 s
GBM_located False
mjd 54791.857957175926 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB081121858
trigger_name bn081121858
ra 89.3000°
decl -60.6000°
pos_error 3.46e+00°
datum 2008-11-21
t_trigger 20:35:27.754 UTC
T90 41.985 s
T90_error 8.51 s
T90_start 20:35:29.290 UTC
fluence 1.53e-05 erg/cm²
fluence_error 2.20e-07 erg/cm²
flux_1024 7.72e+00 erg/cm²/s
flux_1024_error 3.80e-01 erg/cm²/s
flux_1024_time 1.52e+01 erg/cm²/s
flux_64 1.28e+01 erg/cm²/s
flux_64_error 1.66e+00 erg/cm²/s
IPN table
GRB_name GRB081121A
ra 89.2625°
decl -60.6333°
pos_error 5.00e-02°
redshift 2.5120
Swift table
GRB_name GRB081121A
t_trigger 20:35:32 UTC
ra 89.2756°
decl -60.6028°
pos_error 7.77e-05°
T90 14.0 s
fluence 4.10e-06 erg/cm²
redshift 2.5120
GCN 8536 table
GRB_name GRB081121A
GCN_number 8536
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8536 SUBJECT: GRB 081121: ROTSE-III Detection of Optical Counterpart DATE: 08/11/21 20:41:23 GMT FROM: Fang Yuan at ROTSE F. Yuan (U Mich), W. Rujopakarn (Steward) report on behalf of the ROTSE collaboration: ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 081121 (Swift trigger 335105). The first image was at 20:36:30.0 UT, 57.2 s after the burst (8.9 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 11.6 magnitude, fading source with coordinates: 05:57:06.1 -60:36:10.3 (J2000), with positional uncertainty of 1" or better start UT mag mlim(of image) ---------------------------------- 20:36:29.9 11.6 15.7 This source is not visible in DSS (second epoch), 2MASS or the MPChecker database. A jpeg image is available at http://www.rotse.net/images/gsb335105_3c00_img.jpg Note that the object marked 4 is the candidate in question. Continuing observations are in progress.
GCN 8537 table
GRB_name GRB081121A
GCN_number 8537
Detection_method Swift Det
t_trigger 20:35:32 UTC
ra 89.2640°
decl -60.6260°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8537 SUBJECT: GRB 081121: Swift detection of a burst DATE: 08/11/21 20:48:42 GMT FROM: David Palmer at LANL S. R. Oates (UCL-MSSL), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Schady (MSSL-UCL), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), L. Vetere (PSU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 20:35:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 081121 (trigger=335105). Due to an Earth limb constraint slew could not immediately slew to this burst. The BAT on-board calculated location is RA, Dec 89.264, -60.626 which is RA(J2000) = 05h 57m 03s Dec(J2000) = -60d 37' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single FRED structure with a duration of about 15 sec, with overlying spikes. There may be continued low-level emission out to 100 seconds. The peak count rate was ~4000 counts/sec (15-350 keV), at ~1.5 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+45.2 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is S. R. Oates (sro 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 8538 table
GRB_name GRB081121A
GCN_number 8538
Detection_method Swift-UVOT Det
ra 89.2758°
decl -60.6029°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8538 SUBJECT: GRB081121: Swift/UVOT observations DATE: 08/11/21 22:19:23 GMT FROM: Samantha Oates at MSSL S. R. Oates and P. Schady (MSSL-UCL) report on behalf of the Swift UVOT team: The Swift/UVOT began observing the field of GRB081121 starting 2816 seconds after the BAT trigger (Oates et al., GCN 8537) with a White finding chart exposure of 150 seconds. There is a candidate afterglow in the 2.7'x2.7' sub- image at RA(J2000) = 05:57:06.19 = 89.27581 DEC(J2000) = -60:36:10.3 = -60.60286 with a 90%-confidence error radius of about 0.62 arc sec. This position is 0.7 arc sec. from the center of the XRT error circle and is consistent with the position of the optical afterglow found by ROTSE-IIIc (Yuan el al., GCN 8536). The estimated magnitude is 17.98 with a 1-sigma error of about 0.04. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05.
GCN 8539 table
GRB_name GRB081121A
GCN_number 8539
Detection_method Swift-BAT Det
ra 89.2820°
decl -60.6120°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8539 SUBJECT: GRB 081121: Swift-BAT refined analysis DATE: 08/11/22 00:09:10 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC/UMBC), 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), S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-119 to T+271 sec from the recent telemetry downlink, we report further analysis of BAT GRB 081121 (trigger #335105) (Oates, et al., GCN Circ. 8537). The BAT ground-calculated position is RA, Dec = 89.282, -60.612 deg, which is RA(J2000) = 05h 57m 07.7s Dec(J2000) = -60d 36' 42.1" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 5%. The mask-weighted light curve shows an approximately square-shaped pulse with a trailing spike. The pulse starts at ~T-10 sec and ends at ~T=15 sec. There is a hint of low-level precursor emission starting before T-119 sec (the beginning of the saved event-by-event data). T90 (15-350 keV) is 14 +- 2 sec (estimated error including systematics). The time-averaged spectrum from T-2.8 to T+12.9 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.43 +- 0.54, and Epeak of 123 +- 69 keV (chi squared 44.9 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.1 +- 0.3 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+6.94 sec in the 15-150 keV band is 4.4 +- 1.0 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.21 +- 0.12 (chi squared 52.0 for 57 d.o.f.). 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/335105/BA/
GCN 8540 table
GRB_name GRB081121A
GCN_number 8540
Detection_method GROND
Circular_text TITLE: GCN CIRCULAR NUMBER: 8540 SUBJECT: GRB 081121: GROND observations DATE: 08/11/22 03:02:14 GMT FROM: Sebastian Loew at MPE S. Loew, T. Kruehler and J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 081121 (Swift trigger #335105; Oates et al., GCN #8537) 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 La Silla Observatory (Chile). Observations started at 00:30 UT on November 22nd, 2008, 3.9 hr after the burst at a high airmass of 2.35, and are continuing. We detect the optical afterglow reported by Yuan et al. (GCN #8536) and Oates & Schady (GCN #8538) clearly in all filters. At a midtime of 3.9454 hours after the burst, we estimate the following preliminary magnitudes (all in AB system) in stacked images of 4 x 35s integration in g'r'i'z' and 24 x 10s integration in JHK: g' = 19.1 r' = 18.8 i' = 18.6 z' = 18.5 J = 18.4 H = 18.2 K = 18.1 with typical errors of 0.2 mag, which are mostly due to a preliminary calibration using GROND zeropoints in g'r'i'z' and 2MASS field stars in JHK.
GCN 8541 table
GRB_name GRB081121A
GCN_number 8541
Detection_method Swift-XRT Det
ra 89.2757°
decl -60.6028°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8541 SUBJECT: GRB 081121: Enhanced Swift-XRT position DATE: 08/11/22 05:00:10 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 939 s of XRT Photon Counting mode data and 3 UVOT images for GRB 081121, 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 = 89.2757, -60.6028 which is equivalent to: RA (J2000): 05h 57m 6.17s Dec (J2000): -60d 36' 10.1" 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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method. This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 8542 table
GRB_name GRB081121A
GCN_number 8542
Detection_method Optical
redshift 2.5120
Circular_text TITLE: GCN CIRCULAR NUMBER: 8542 SUBJECT: GRB 081121: Magellan Redshift DATE: 08/11/22 05:21:25 GMT FROM: Edo Berger at Harvard E. Berger (Harvard) and M. Rauch (Carnegie) report: "We obtained spectroscopic observations of the optical afterglow of GRB 081121 (GCNs 8536,8537) with the LDSS3 spectrograph on the Magellan/Clay 6.5-m telescope starting on 2008 Nov 22.16 UT. The spectra cover the wavelength range 3800-6500A. We detect Ly-alpha absorption, as well as aborption features corresponding to SiII, CII, SiIV, CIV, FeII, and AlII at a redshift of z=2.512, which we consider the redshift of the burst. Further analysis is in progress."
GCN 8543 table
GRB_name GRB081121A
GCN_number 8543
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8543 SUBJECT: GRB 081121: Swift-XRT refined analysis DATE: 08/11/22 11:43:57 GMT FROM: Olivier Godet at U.of Leicester O. Godet (U Leicester) and S. Oates (UCL-MSSL) on behalf the Swift-XRT team: The Swift-XRT started observing the field of GRB 081121 (trigger number 335105, Oates et al., GCN Circ. 8537) at 2008-11-21 20:35:32 UT, 2.8 ks after the trigger. The best XRT position is the UVOT-enhanced position reported by Goad et al. (GCN Circ. 8541). This position is consistent with the optical positions reported by the Swift-UVOT and ROTSE III (Oates et al., GCN Circ. 8538; Yuan et al., GCN Circ. 8536). The X-ray light curve presently spans 4.2 ks of photon counting (PC) mode data from T+2.8 ks to T+16 ks. The light curve shows an initial decay with a slope of 1.11 +0.06/-0.05 up to at least ~T+17 ks, followed by a steep decay up to ~T+20 ks and then a flatter decay with a slope of 0.25 +0.62/-0.13. The PC X-ray spectrum from the same interval can be well fit by an absorbed power-law with a photon index of 1.99 +0.10/-0.09 and a column density of (9.7 +2.2/-2.0) x 10^20 cm^-2 (the Galactic value is 4.0 x 10^20 cm^-2 in the direction of the burst). The observed 0.3-10.0 keV flux is (7.1 +/-0.4) x 10^-11 erg cm^-2 s^-1 which corresponds to an unabsorbed flux of (9.0 +0.2/-0.5) x 10^-11 erg cm^-2 s^-1. If the burst continues on the current plateau phase, the predicted count rate at T+1 day would be approximately 1.2 x 10^-1 count s^-1. This is an official product of the Swift-XRT team.
GCN 8544 table
GRB_name GRB081121A
GCN_number 8544
Detection_method Swift-UVOT Det
ra 89.2756°
decl -60.6028°
redshift 2.5120
Circular_text TITLE: GCN CIRCULAR NUMBER: 8544 SUBJECT: GRB081121: Refined Swift/UVOT observations DATE: 08/11/22 12:13:02 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 081121, 2816s after the BAT trigger (Oates et al., GCN Circ. 8537). We detect the optical afterglow in the white, v, b, u filters and marginally in the uvw1 filter at the position: RA(J2000) = 5:57:06.15 DEC(J2000) = -60:36:10.0 with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence). This position is consistent with the UVOT-enhanced XRT position and the position reported by ROTSE-IIIC (Yuan et al., GCN Circ. 8536). The marginal detection of the optical afterglow in uvw1, and the lack of a detection in the uvm2 and uvw2 filters is consistent with a redshift of z=2.512 reported by Magellan (Berger and Rauch, GCN Circ. 8542). The magnitudes and 3 sigma upper limits are reported below: Filter T_start (s) T_stop Exposure Mag/3sig UL --------------------------------------------------------- white 2816 2965 147 17.93 +/- 0.04 v 2972 3172 197 17.58 +/- 0.08 b 3792 3992 197 18.26 +/- 0.07 u 3587 3787 197 17.62 +/- 0.06 uvw1 3383 3582 197 20.60 +/- 0.48 (2.3-sigma) uvm2 3177 4813 393 > 20.09 uvw2 4203 11200 790 > 20.78 --------------------------------------------------------- The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.05 mag (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT flight system described in Poole et al. (2008, MNRAS, 383,627).
GCN 8546 table
GRB_name GRB081121A
GCN_number 8546
Detection_method Fermi GBM Det
t_trigger 20:35:27.500 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 8546 SUBJECT: GRB081121: Fermi GBM detection DATE: 08/11/22 23:06:39 GMT FROM: Colleen A. Wilson at NASA/MSFC/NSSTC Colleen A. Wilson-Hodge (NASA/MSFC) and Valerie Connaughton (UAH) report on behalf of the Fermi GBM Team: "At 20:35:27.5 UT on 21 November 2008, the Fermi Gamma-Ray Burst Monitor triggered on GRB 081121 (trigger 248992528/ 081121.858). This burst triggered Swift-BAT 4 seconds later (Oates et al 2008, GCN 8537) and an optical counterpart was detected with ROTSE-III (Yuan et al. 2008, GCN 8536). The burst direction was 135 degrees from the Fermi pointing-axis so the Fermi GBM sensitivity to this GRB is limited. Further analysis is necessary to provide meaningful spectral information about this burst. Final spectral analysis results will be published in the GBM GRB Catalog."
GCN 8547 table
GRB_name GRB081121A
GCN_number 8547
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8547 SUBJECT: GRB 081121, SMARTS optical/IR afterglow observations DATE: 08/11/23 00:27:49 GMT FROM: Bethany Cobb at UC Berkeley B. E. Cobb (UC Berkeley) reports: Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained several epochs of optical/IR imaging of the error region of GRB 081121 (GCN 8537, Oates et al.). Each epoch consisted of several dithered images in each filter, with total summed exposure times of 180s in each of BRIJK and 120s in each of H and V. At a mid-exposure time of 2008-11-22 02:02 (5.4 hrs post-burst), the GRB afterglow (GCN 8536, Yuan et al.) is detected with the following magnitudes: B = 19.34 +/- 0.04 R = 18.61 +/- 0.04 I = 18.21 +/- 0.04 J = 17.21 +/- 0.15 H = 17.05 +/- 0.15 K = 16.75 +/- 0.15 Observations were obtained under non-photometric conditions. In optical, these preliminary magnitudes are calibrated against several USNO-B1.0 stars in the field, so there is likely an additional photometric calibration error of ~0.3 magnitudes. In the IR, calibration is against 2MASS stars. Between 5.4 hrs and 8.7 hours post-burst, the afterglow decays with an approximate optical decay rate of alpha~-1 (where afterglow flux is proportional to t^alpha).
GCN 8548 table
GRB_name GRB081121A
GCN_number 8548
Detection_method Konus-Wind Det
t_trigger 20:35:31.435 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 8548 SUBJECT: Konus-Wind observation of GRB 081121 DATE: 08/11/23 16:07:29 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov and T. Cline, on behalf of the Konus-Wind team report: The long GRB 081121 (Swift-BAT trigger #335105: Oates et al., GCN 8537, Sakamoto et al. 8539) triggered Konus-Wind at T0=74131.435 s UT (20:35:31.435). The burst light curve shows a multipeaked structure with a total duration of ~18 s. As observed by Konus-Wind the burst had a fluence of 1.79(-0.31, +0.37)x10^-5 erg/cm2, and a 256-ms peak flux measured from T0+16.368 s of 2.60(-0.63, +0.70)x10^-6 erg/cm2/s (both in the 20 keV - 7 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.640 s) is well be fitted (in the 20 keV - 7 MeV range) by GRB (Band) model for which: the low-energy photon index is alpha = -0.77(-0.14, +0.15), the high energy photon index beta = -2.51(-0.66, +0.31), the peak energy Ep = 248(-32, +38) keV (chi2 = 92.3/79 dof). All the quoted errors are at the 90% confidence level. Assuming z = 2.512 (Berger & Rauch, GCN 8542) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_\Lambda = 0.73, the isotropic energy release E_iso ~2.7x10^53 erg, the peak luminosity (L_iso)_max ~ 1.4x10^53 erg/s, and Ep_rest ~870 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB081121_T74131/
GCN 8643 table
GRB_name GRB081121A
GCN_number 8643
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8643 SUBJECT: Radio observation of GRB 081121 with ATCA DATE: 08/12/09 02:14:46 GMT FROM: Aquib Moin at CIRA/ATNF Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope National Facility), Steven Tingay (Curtin Institute of Radio Astronomy), Chris Phillips (Australia Telescope National Facility), Gregory Taylor (University of New Mexico), Mark Wieringa (Australia Telescope National Facility) and Ralph Martin (Perth Observatory) report: We observed the SWIFT-UVOT refined position of the GRB 081121 optical afterglow (GCN 8544) at 4.800 and 4.928 GHz with the Australia Telescope Compact Array (ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30 UT, November 25, 2008. We did not detect a radio source at the optical afterglow position of the GRB 081121 (GCN 8544). The data at 4.800 and 4.928 GHz were merged and the radio flux density at the afterglow position found out to be 0.106 +/- 0.208 mJy/beam (1-sigma). The Australia Telescope Compact Array (/ Parkes telescope / Mopra telescope / Long Baseline Array) is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. See the 4.800 & 4.928 GHz combined image at: http://cira.ivec.org/dokuwiki/doku.php/grb/grb081121_field_image