GRB081024A

This page lists all entries on GRB081024A in GRBweb

Summary Fermi GBM IPN Swift GCN 8398 GCN 8399 GCN 8400 GCN 8401 GCN 8402 GCN 8403 GCN 8404 GCN 8405 GCN 8406 GCN 8419

Summary table
Variable Value Source
GRB_name_Fermi GRB081024245
T0 5:53:00 UTC Swift
ra 27.8742° Swift
decl 61.3312° Swift
pos_error 2.33e-04° Swift
T90 0.832 s Fermi_GBM
T90_error 1.282 s Fermi_GBM
T90_start 5:53:08.174 UTC Fermi_GBM
fluence 1.99e-07 erg/cm² Fermi_GBM
fluence_error 1.69e-08 erg/cm² Fermi_GBM
T100 9.006 s
GBM_located False
mjd 54763.24513888889 Swift
Fermi GBM table
GRB_name_Fermi GRB081024245
trigger_name bn081024245
ra 27.9000°
decl 61.3000°
datum 2008-10-24
t_trigger 5:53:09.006 UTC
T90 0.832 s
T90_error 1.282 s
T90_start 5:53:08.174 UTC
fluence 1.99e-07 erg/cm²
fluence_error 1.69e-08 erg/cm²
flux_1024 1.85e+00 erg/cm²/s
flux_1024_error 2.94e-01 erg/cm²/s
flux_1024_time -8.32e-01 erg/cm²/s
flux_64 6.80e+00 erg/cm²/s
flux_64_error 1.38e+00 erg/cm²/s
IPN table
GRB_name GRB081024A
ra 27.9000°
decl 61.3500°
pos_error 5.00e-02°
Swift table
GRB_name GRB081024A
t_trigger 5:53:00 UTC
ra 27.8742°
decl 61.3312°
pos_error 2.33e-04°
T90 1.8 s
fluence 1.20e-07 erg/cm²
GCN 8398 table
GRB_name GRB081024A
GCN_number 8398
Detection_method Swift Det
t_trigger 5:53:08 UTC
ra 27.8980°
decl 61.3460°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8398 SUBJECT: GRB 081024: Swift detection of a burst DATE: 08/10/24 06:18:55 GMT FROM: Neil Gehrels at GSFC G. Stratta (ASDC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), C. B. Markwardt (CRESST/GSFC/UMD), M. Perri (ASDC) and L. Vetere (PSU) report on behalf of the Swift Team: At 05:53:08 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 081024 (trigger=332516). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 27.898, +61.346 which is RA(J2000) = 01h 51m 36s Dec(J2000) = +61d 20' 47" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a short hard peak with a duration of about 0.3 sec at T+0 with a short precursor peak at T-2.5 seconds. The peak count rate was ~6,000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 05:54:21.1 UT, 72.3 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 27.8745, 61.3317 which is equivalent to: RA(J2000) = 01h 51m 29.88s Dec(J2000) = +61d 19' 54.1" with an uncertainty of 2.3 arcseconds (radius, 90% containment). This location is 65 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 7.71e+21 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of nominal 150 seconds with the White (160-650 nm) filter starting 76 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. Image catalog data are not available at this time. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain extinction expected. This appears to be a short hard GRB with a precursor and a fading X-ray afterglow. We note that the position in galactic coordinates is l=130deg, b=-0.7 deg. It is not impossible that this is a galactic transient or even an SGR. Burst Advocate for this burst is G. Stratta (giulia.stratta AT asdc.asi.it). 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 8399 table
GRB_name GRB081024A
GCN_number 8399
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8399 SUBJECT: GRB 081024A: ROTSE-III Optical Limits DATE: 08/10/24 06:33:52 GMT FROM: Brad Schaefer at LSU B. E. Schaefer (Louisiana State), E.S. Rykoff (UCSB), H. Swan (U Mich), W. Rujopakarn (Steward), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 081024A (Swift trigger 332516; G. Stratta, GCN 8398), producing images beginning 9.1 s after the GCN notice time. An automated response took the first image at 05:53:37.2 UT, 28.4 s after the burst, under excellent conditions. We took 10 5-sec, 10 20-sec and 40 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going. Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle or the XRT error circle, for both single images and coadding into sets of 10; however, we are limited as the field is somewhat crowded. Individual images have limiting magnitudes ranging from 16.1-17.1; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 05:53:37.1 05:53:42.1 5 16.2 28.3 N 05:54:57.0 05:59:37.7 280 17.2 108.2 Y
GCN 8400 table
GRB_name GRB081024A
GCN_number 8400
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8400 SUBJECT: GRB 081024: Early Super-LOTIS Observations DATE: 08/10/24 08:10:37 GMT FROM: Grant Williams at Steward Observatory G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of the Super-LOTIS Collaboration, report: The robotic 0.6-m Super-LOTIS telescope began observing the error box of GRB 081024 (Swift Trigger 332516, Stratta et al. GCN 8398) at 05:53:49.9 UT, 41.9 seconds after the trigger. Our initial observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all in the R-band. We do not detect any variable sources or afterglow candidates within the XRT error box in our earliest exposure to the following 3-sigma limiting magnitude determined from the nearby USNO-B1.0 star 1513-0063175 with R2=14.24: t_start (UT) exp t (s) t_start-t_0 (s) Limit ------------------------------------------------------------ 05:53:49.9 10 41.9 R > 17.6 The value quoted above is not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V)=1.64 mag in the direction of the burst (Schlegel et al. 1998). Additional observations and analysis are ongoing.
GCN 8401 table
GRB_name GRB081024A
GCN_number 8401
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8401 SUBJECT: GRB 081024: KAIT Optical Limits DATE: 08/10/24 08:16:22 GMT FROM: Weidong Li at UC Berkeley KAIT/LOSS W. Li, R. Chornock, and A. V. Filippenko, University of California at Berkeley, on behalf of the KAIT GRB team, report: The robotic 0.8-m KAIT located at Lick Observatory responded to GRB 081024 (G. Stratta, GCN 8398) automatically and started the first image at 05:54:42 UT (94 seconds after the burst). A series of images were taken in the V, I, and clear filters. No new sources were detected within the Swift/XRT error circle in the KAIT images (single or stacked frames) when compared to the DSS II. We set the following specific limiting magnitude in a stacked unfiltered image (2s x 10; USNO B1 calibration): start UT end UT t_exp(s) mlim -------------------------------------------- 05:54:42.0 05:55:16.0 20 18.8
GCN 8402 table
GRB_name GRB081024A
GCN_number 8402
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8402 SUBJECT: GRB 081024: Faulkes Telescope North optical observations DATE: 08/10/24 10:56:02 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri, M. Burgdorf, R.J. Smith, I.A. Steele, D.F. Bersier, C.G. Mundell, (Liverpool JMU), A. Gomboc (Ljubljana), C. Guidorzi (INAF-OAB) on behalf of a larger collaboration report: On 2008 October 24 at 05:54:45 UT (~50 seconds after the GRB trigger) we observed the field of GRB 081024 (trigger = 332516, Stratta et al., GCN 8938) with the robotic 2m Faulkes Telescope North located in Hawaii. Observations were performed on BVRi filters. We do not detect any fadind optical source within the XRT error circle (Stratta et al., GCN 8938) down to the following limits: -------------------------------------------------- Dt_mid T_exp Filter Mag_lim [min] [sec] -------------------------------------------------- 2.25 30 R > 21.4 112.8 600 R > 22.6 136.2 600 I > 21.2 -------------------------------------------------- Limiting magnitudes has been estimated using the R2 and I magnitudes of the USNOB-1 catalogue. The reported values are not corrected for the Galactic extinction.
GCN 8403 table
GRB_name GRB081024A
GCN_number 8403
Detection_method Swift-XRT Det
ra 27.8738°
decl 61.3314°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8403 SUBJECT: GRB 081024: Enhanced Swift-XRT position DATE: 08/10/24 11:53:14 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 1443 s of XRT Photon Counting mode data and 1 UVOT images for GRB 081024, 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 = 27.8738, +61.3314 which is equivalent to: RA (J2000): 01h 51m 29.72s Dec (J2000): +61d 19' 53.0" with an uncertainty of 1.9 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 8404 table
GRB_name GRB081024A
GCN_number 8404
Detection_method Swift-BAT Det
ra 27.8910°
decl 61.3520°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8404 SUBJECT: GRB 081024, Swift-BAT refined analysis DATE: 08/10/24 14:51:55 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift 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), K. McLean (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), G. Stratta (ASDC), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 081024 (trigger #332516) (Stratta, et al., GCN Circ. 8398). The BAT ground-calculated position is RA, Dec = 27.891, 61.352 deg which is RA(J2000) = 01h 51m 33.8s Dec(J2000) = +61d 21' 08.2" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). This position is 1.3 arcmin from the enhanced XRT position (Beardmore et al. GCN Circ. 8403). The partial coding was 97%. The mask-weighted lightcurve shows a slightly softer precursor peak about 0.05 sec long at T-1.7 sec, a peak about 0.3 seconds long at T-0.2 sec and the largest peak 0.1 seconds long at T0. T90 (15-350 keV) is 1.8 +- 0.6 sec (estimated error including systematics). The time-averaged spectrum from T-1.7 to T+0.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.23 +- 0.21. The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10-07 erg/cm2. The 1-sec peak photon flux measured from T-0.73 sec in the 15-150 keV band is 1.1 +- 0.1 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/332516/BA/
GCN 8405 table
GRB_name GRB081024A
GCN_number 8405
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8405 SUBJECT: GRB 081024: Swift-XRT refined analysis DATE: 08/10/24 20:31:08 GMT FROM: Matteo Perri at ISAC/ASDC G. Stratta (ASDC) reports on behalf of the Swift-XRT team: We have analysed the first orbit of the XRT data obtained for GRB 081024 (Stratta et al., GCN Circ. 8398). From T+78 s to T+105 s after the burst, data were collected in Windowed Timing mode and then XRT switched to Photon Counting mode. The Enhanced Swift-XRT position was given by Beardmore et al. in GCN Circ. 8403. The 0.3-10 keV flux from T+78 s to T+355 s shows a very steep decay with a possible small re-brightening between ~T+145 s to ~T+205 s. Excluding the re-brightening and assuming a power law decay, the best fit decay index is alpha = 3.7 (+0.8,-0.5). The spectrum of the WT data, with an integration time of 27s, can be modelled with a power-law model with photon index of 1.6 (+0.6,- 0.3). The total absorbing equivalent hydrogen column density is consistent with the Galactic one NH = 7.71E+21 cm^-2 (Kalberla et al. 2005). The observed (unabsorbed) 0.3-10 keV flux is 4.1(6.1)E-10 erg/cm^-2 s^-1 No source counts are detected after the first orbit, likely due to the very steep flux decay. This is an official product of the Swift-XRT team.
GCN 8406 table
GRB_name GRB081024A
GCN_number 8406
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8406 SUBJECT: Swift UVOT observations of GRB 081024 DATE: 08/10/25 11:53:56 GMT FROM: Patricia Schady at MSSL/Swift M. De Pasquale (MSSL/UCL) and G. Stratta (ASDC) report on behalf of the Swift UVOT team. The Swift UltraViolet/Optical Telescope (UVOT) began its finding chart exposure of GRB081024 (Swift BAT trigger number 332516, Stratta et al., GCN Circ. 8398), 77s after the trigger. We do not detect any new source at the XRT position reported in GCN Circ. 8403 (Beardmore et al.) either in the finding chart nor in in successive coadded observations. The magnitude 3 sigma upper limits for detecting GRB081024 at the XRT position are given below. Filter Tstart(s) Tstop(s) Exp(s) Magnitude wh 77 227 147 >20.8 wh 516 13395 1258 >22.0 v 565 758 39 >18.5 v 1041 7298 490 >19.9 b 491 856 58 >19.6 b 1140 12771 1358 >21.4 u 235 485 250 >20.1 u 639 11859 807 >21.0 uvw1 615 7615 436 >20.2 uvm2 590 7503 529 >20.5 uvw2 541 7093 529 >20.6 The values quoted above are on the UVOT Photometric System (Poole et al, 2008, MNRAS 383,627). They are not corrected for the unknown but expected large Galactic extinction in the direction of this burst.
GCN 8419 table
GRB_name GRB081024A
GCN_number 8419
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8419 SUBJECT: GRB 081024: No radio detection with the VLA DATE: 08/10/27 14:56:12 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 081024 (GCN 8398) at a frequency of 8.46 GHz at 2008 Oct. 25.27 UT. The GRB radio afterglow is undetected and the peak radio flux at the Swift XRT afterglow position (GCN 8403) is -36 52 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."