GRB091024A

This page lists all entries on GRB091024A in GRBweb

Summary Fermi GBM IPN Swift GCN 10062 GCN 10063 GCN 10064 GCN 10065 GCN 10066 GCN 10067 GCN 10069 GCN 10070 GCN 10072 GCN 10073 GCN 10074 GCN 10075 GCN 10077 GCN 10078 GCN 10083 GCN 10086 GCN 10092 GCN 10093 GCN 10101 GCN 10114 GCN 10116

Summary table
Variable Value Source
GRB_name_Fermi GRB091024372
T0 8:55:55.400 UTC Fermi_GBM
ra 339.2400° Swift
decl 56.8850° Swift
pos_error 7.77e-03° Swift
T90 93.954 s Fermi_GBM
T90_error 5.221 s Fermi_GBM
T90_start 8:55:55.400 UTC Fermi_GBM
fluence 8.56e-06 erg/cm² Fermi_GBM
fluence_error 6.01e-08 erg/cm² Fermi_GBM
redshift 1.0920
T100 115.4 s
GBM_located False
mjd 55128.372168981485 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB091024372
trigger_name bn091024372
ra 339.2521°
decl 56.8892°
pos_error 3.57e+00°
datum 2009-10-24
t_trigger 8:55:58.472 UTC
T90 93.954 s
T90_error 5.221 s
T90_start 8:55:55.400 UTC
fluence 8.56e-06 erg/cm²
fluence_error 6.01e-08 erg/cm²
flux_1024 4.23e+00 erg/cm²/s
flux_1024_error 3.32e-01 erg/cm²/s
flux_1024_time 2.24e+00 erg/cm²/s
flux_64 5.65e+00 erg/cm²/s
flux_64_error 1.16e+00 erg/cm²/s
IPN table
GRB_name GRB091024A
ra 339.2083°
decl 56.8667°
pos_error 5.00e-02°
redshift 1.0920
Swift table
GRB_name GRB091024A
t_trigger 8:56:01 UTC
ra 339.2400°
decl 56.8850°
pos_error 7.77e-03°
T90 109.8 s
fluence 6.10e-06 erg/cm²
redshift 1.0920
GCN 10062 table
GRB_name GRB091024A
GCN_number 10062
Detection_method Swift Det
t_trigger 8:56:01 UTC
ra 339.2070°
decl 56.8740°
Circular_text TITLE: GCN CIRCULAR NUMBER: 10062 SUBJECT: GRB 091024: Swift detection of a burst DATE: 09/10/24 09:09:05 GMT FROM: David Palmer at LANL F. E. Marshall (NASA/GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), S. Campana (INAF-OAB), P. A. Evans (U Leicester), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA), R. L. C. Starling (U Leicester) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 08:56:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 091024 (trigger=373674). The BAT on-board calculated location is RA, Dec 339.207, +56.874 which is RA(J2000) = 22h 36m 50s Dec(J2000) = +56d 52' 28" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with the first peak at T=0 and a second smaller peak at T=40s with a total duration of about 50 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+50.0 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 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 10063 table
GRB_name GRB091024A
GCN_number 10063
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 10063 SUBJECT: GRB 091024: Faulkes Telescope North Afterglow Candidate DATE: 09/10/24 09:43:48 GMT FROM: Carole Mundell at ARI, JMU,Liverpool C.G. Mundell, Z. Cano (Liverpool, JMU), C. Guidorzi (U. Ferrara), I. A. Steele, A. Melandri, D. Bersier, S. Kobayashi, C.J. Mottram, R.J. Smith (Liverpool, JMU), A. Gomboc, D. Kopac (U. Ljubljana), P. O'Brien (U. Leicester) report: "The 2-m Faulkes Telescope North robotically followed up GRB091024 (SWIFT trigger 373674; Marshall et al. GCN 10062) 3.27 min after the GRB trigger time. The automatic "detection mode" procedure detected an uncatalogued afterglow candidate at: 22:36:59.7 +56:53:23.4 (J2000) uncertainty 0.5" with magnitude R = 18.1 +/-mag (vs USNOB1) Observations and analysis are ongoing. This message may be cited"
GCN 10064 table
GRB_name GRB091024A
GCN_number 10064
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 10064 SUBJECT: GRB 091024: GRAS004 optical observations DATE: 09/10/24 13:21:42 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Markku Nissinen (Taurus Hill Observatory) and Veli-Pekka Hentunen (Taurus Hill Observatory) report: We used Global-rent-a-scope GRAS004 Epsilon 250 telescope with ST-8XE CCD at RAS Observatory Mayhill H06 (New Mexico, USA) for follow-up observations of GRB091024 (D.Palmer et al. , GCN 10062). The observations were started on October 24, at 09:44 UTC (48 min after the burst) and stopped on October, at 09:58 UTC. One unfiltered 120 seconds image and one unfiltered 600 seconds image were taken. We detected a very dim uncatalogued optical afterglow object at the position of RA 22h 36min 59s.68 and DEC +56o 53' 22".6 with respect to POSSII F (J2000) which is in good correlation with Carole Mundell et al. observation (GCN 10063). Upper limit for our observations is >18.7 mag. Quoted upper limit has been derived using POSSII F and USNO-B1.0 field stars as reference. Filter Tmid(s) Exp(s) OA Mag (CR) USNO-B1.0 unfiltered 09:53:11 600 18.2+/-0.4
GCN 10065 table
GRB_name GRB091024A
GCN_number 10065
Detection_method Other
redshift 1.0920
Circular_text TITLE: GCN CIRCULAR NUMBER: 10065 SUBJECT: GRB 091024 Gemini-North redshift DATE: 09/10/24 13:49:15 GMT FROM: Nial Tanvir at IofA U.Cambridge A. Cucchiara, D. Fox (PSU) & N. Tanvir (U. Leicester) report: We observed the afterglow of GRB 091024 (Marshall et al. GCN 10062; Mundell et al. GCN 10063) with the GMOS-N spectrograph on Gemini North beginning at 10.43 UT. The resultant spectrum, which spans 5925A to 10200A, shows a strong continuum and well detected lines of CaII H & K, MgI (2853A) at a common redshift of z=1.092. Further analysis is ongoing. We thank the Gemini-N support staff, in particular R. Pike, for obtaining these observations.
GCN 10066 table
GRB_name GRB091024A
GCN_number 10066
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 10066 SUBJECT: GRB 091024 : Faulkes Telescope North - Afterglow Confirmation DATE: 09/10/24 14:03:43 GMT FROM: Zach Cano at ARI/John Moores Liverpool Z. Cano (Liverpool JMU), C. Guidorzi (U. Ferrara), C.G. Mundell, D. Bersier, N.R. Clay, S. Kobayashi, A. Melandri, C.J. Mottram, R.J. Smith, I.A. Steele (Liverpool JMU), A. Gomboc (U. Ljubljana), P. O'Brien, N.R. Tanvir (U. Leicester) on behalf of a larger collaboration report: The Faulkes Telescope North (Hawaii) continued observing the field of GRB 091024 (Swift trigger=373674, Marshall et al., GCN 10062). We have detected an initial rise in the R & I LCs, peaking around To+600s with 16.7 Rmag, which was followed by flaring activity that lasted approximate 6ks. After 6ks we estimate from our data a power-law decay index alpha = 1.7 +/- 0.2. As calibrated against nearby USNO objects, we find: Filter mag merr T-To (hr) --------------------------------------- R 17.55 0.05 0.98 R 17.98 0.05 1.84 R 19.09 0.08 3.30 We also note the large amount of foreground extinction, E(B-V) = 0.98 mag (Schlegel et al. 98), corresponding to AV=3.0 mag.
GCN 10067 table
GRB_name GRB091024A
GCN_number 10067
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 10067 SUBJECT: GRB 091024: Xinglong TNT optical observation DATE: 09/10/24 14:41:05 GMT FROM: L.P. Xin at NAOC H.Li, L.P. Xin, J. Wang, Y.L. Qiu, J.Y. Wei, W. K. Zheng, J.S. Deng, and C. Wu, J.Y. Hu on behalf of EAFON report: We have observed GRB 091024 (Marshall et al. GCN 10062) with Xinglong TNT telescope from Oct. 24, 10:27:11 (UT), 1.3 hour after the burst. The optical afterglow (Cano et al. GCN 10066; Cucchiara et al. GCN 10065; Mundell et al. GCN 10063) has been detected in our images. The brightness is estimated to be about R~18.5 mag derived from USNO-A1.0 R magnitude, at the mean time of 1.38 hour since the trigger. The observation is still going. 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 10069 table
GRB_name GRB091024A
GCN_number 10069
Detection_method Swift-XRT Other
ra 339.2517°
decl 56.8893°
redshift 1.0920
Circular_text TITLE: GCN CIRCULAR NUMBER: 10069 SUBJECT: GRB 091024: Swift-XRT team refined analysis DATE: 09/10/24 14:51:19 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester) and F.E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team: Following an Earth-limb constraint, Swift-XRT began observing the field of GRB 091024 at 09:49:13, about 53 minutes after the BAT trigger. We detect a bright, uncatalogued X-ray source at a position of RA, Dec = 339.25167, 56.88928, which is equivalent to RA (J2000): 22 37 00.40 Dec (J2000): 56 53 21.4 with an uncertainty of 6 arcsec (radius, 90% confidence). This is 6.1 arcsec from the optical afterglow candidate given by Mundell et al. (GCN Circ. 10063) and 6.0 arcsec from the position given by Nissinen & Hentunen (GCN Circ. 10064). Only one orbit of data has been collected thus far (spanning 3.2-5.4 ks after the burst), but the source does appear to be fading, albeit with a relatively large uncertainty: alpha = 1.2 +/- 0.4. The spectrum of the source, extracted from the 2.2 ks of Photon Counting mode data, can be fitted by an absorbed power-law with Gamma = 1.70 +/- 0.17, the Galactic column of NH = 4.86 x 10^21 cm^-2 and an intrinsic column of (2.3 +1.0/-0.9) x 10^22 at a redshift of 1.092 (Cucchiara, Fox & Tanvir, GCN Circ. 10065). The observed (unabsorbed) flux over this time is 7.23 x 10^-11 (1.15 x 10^-10) erg cm^-2 s^-1, corresponding to a counts to observed (unabsorbed) flux conversion of 7.5 x 10^-11 (1.2 x 10^-10) erg cm^-2 count^-1. If the source continues to fade with alpha ~ 1.2, the predicted count rate at 24 hours will be 0.034 count s^-1, corresponding to an observed (unabsorbed) flux of 2.6x10^-12 (4.1x10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00373674. This circular is an official product of the Swift-XRT team.
GCN 10070 table
GRB_name GRB091024A
GCN_number 10070
Detection_method Fermi GBM Det
t_trigger 8:55:58.470 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 10070 SUBJECT: GRB 091024: Fermi GBM Observations DATE: 09/10/24 17:12:37 GMT FROM: Valerie Connaughton at MSFC Elisabetta Bissaldi (MPE) and Valerie Connaughton (UAH) report on behalf of the Fermi GBM Team: "At 08:55:58.47 UT on 24 October 2009, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 091024 (trigger 278067360 / 091024372), which was also detected by the Swift-BAT (Marshall et al. 2009, GCN 10062). The GBM on-ground location is consistent with the Swift position. At 09:06:29.36, GBM triggered on what appears to be the continuation of this burst (trigger 278067991 / 091024380). The GBM on-ground location for this second trigger is also consistent with the Swift position for GRB 091024. The angle from the Fermi LAT boresight at the time of the first trigger is 97 degrees and at the time of the second trigger it is 14 degrees. Furthermore, at 09:12:14.28, the Fermi spacecraft executed a maneuver to place the burst near the center of the Large Area Telescope (LAT) field-of-view and observe this region for 5 hours subject to Earth angle constraints. The first emission episode appears to last about 50 s, with 2 peaks separated by a few seconds. A brighter emission periods starts at the time of the 2nd trigger, 630 s later, and persists for at least 400 s. This second emission period shows an initial pulse (at 630 s) lasting about 40 s, followed by a multi-peaked episode starting 210 s later (840 s from the first trigger) and lasting over 100 s. There is evidence for lower-level emission beyond this time. The Fermi spacecraft entered the South Atlantic Anomaly 2200 s after trigger 091024380, by which time there was no obvious emission in GBM. In a first, preliminary analysis, we have fit time-integrated spectra for each of the 3 main emission blocks. The first trigger appears to have an EPeak of about 400 keV; the first peak of the second trigger is quite weak and best fit using a power-law of index around -1.5; the long and brighter emission period of the second trigger has an EPeak of around 300 keV. Detailed spectral analyses and fluence values will be given in a future circular. The POC for this burst is Elisabetta Bissaldi (ebs@mpe.mpg.de).
GCN 10072 table
GRB_name GRB091024A
GCN_number 10072
Detection_method Swift-BAT Det
ra 339.2400°
decl 56.8850°
Circular_text TITLE: GCN CIRCULAR NUMBER: 10072 SUBJECT: GRB 091024: Swift-BAT refined analysis DATE: 09/10/24 17:40:10 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), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+483 sec from the recent telemetry downlink, we report further analysis of BAT GRB 091024 (trigger #373674) (Mashall, et al., GCN Circ. 10062). The BAT ground-calculated position is RA, Dec = 339.240, 56.885 deg, which is RA(J2000) = 22h 36m 57.6s Dec(J2000) = +56d 53' 07.8" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted light curve shows two slightly overlapping FRED peaks. The first starts at ~T-20 sec, peaks at ~T+2 sec. The second peaks at ~T+42 sec and long-term low-level emission extends out to ~T+400 sec. T90 (15-350 keV) is 109.8 +- 16.7 sec (estimated error including systematics). The time-averaged spectrum from T-15.2 to T+135.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.20 +- 0.08. The fluence in the 15-150 keV band is 6.1 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.23 sec in the 15-150 keV band is 2.0 +- 0.3 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/373674/BA/
GCN 10073 table
GRB_name GRB091024A
GCN_number 10073
Detection_method Other
ra 339.1838°
decl 56.8785°
Circular_text TITLE: GCN CIRCULAR NUMBER: 10073 SUBJECT: GRB091024: VRcIc Afterglow Observations DATE: 09/10/24 20:09:04 GMT FROM: Arne A. Henden at AAVSO A. Henden (AAVSO), J. Gross (SRO), B. Denny (DC-3), D. Terrell (SwRI), and W. Cooney (SRO) report: We obtained photometry of the GRB091024 afterglow reported by Mundell et al. (GCN 10063) using the Sonoita Research Observatory (SRO) 35cm telescope in southern Arizona, utilizing an automatic VOevent trigger. The Rc-band exposures began about 9 minutes after the burst and continued for approximately one hour. Ten Rc-band, nine V-band, and one Ic-band exposures were acquired. Photometry, assuming that USNO-B1.0 1468-0448363 (RA: 22:36:44.11 , Dec: +56:52:42.6) has the following magnitudes: V=13.46, R=12.93, I=12.71 UT(mid) delT exp mag err filter 09.1122 642 180 17.177 0.030 Rc 09.1667 839 180 17.510 0.037 Rc 09.2192 1028 180 17.827 0.049 Rc 09.2722 1218 180 17.993 0.044 Rc 09.3247 1407 180 18.136 0.056 Rc 09.4123 1723 300 18.008 0.046 Rc 09.5000 2038 300 17.764 0.045 Rc 09.5859 2348 300 17.737 0.033 Rc 09.6717 2657 300 17.665 0.037 Rc 09.7575 2965 300 17.776 0.045 Rc 09.8609 3338 300 19.029 0.111 V 09.9486 3653 300 19.267 0.120 V 10.0348 3964 300 19.290 0.132 V 10.1206 4273 300 19.320 0.126 V 10.2064 4581 300 19.237 0.091 V 10.2923 4891 300 19.345 0.151 V 10.4642 5510 300 19.163 0.107 V 10.5500 5818 300 19.293 0.123 V 10.6359 6128 300 19.350 0.163 V 10.8439 6877 180 17.550 0.074 Ic Where delT is the time in seconds from the burst (Marshall et al., GCN 10062), and the exposure is in seconds. Astrometry from the Rc frames, using UCAC3, yields a precise position of 22:36:59.68 +56:53:23.3 J2000 (+/- 100mas). A full BVRcIc calibration is in the Sonoita queue and will be released when photometric conditions permit. The AAVSO thanks the Curry Foundation for its support of the AAVSO International High Energy Network.
GCN 10074 table
GRB_name GRB091024A
GCN_number 10074
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 10074 SUBJECT: GRB 091024: Super-LOTIS early observations DATE: 09/10/25 02:37:28 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike, Dieter H. Hartmann (Clemson University), Peter A. Milne (Steward Observatory), and Grant G. Williams (MMT Observatory) report: The 0.6m Super-LOTIS telescope located at Kitt Peak National Observatory began observing the field of GRB 091024 (Marshall et al., GCN 10062) 58 seconds after the BAT trigger under good conditions. We detect the afterglow (Mundell et al., GCN 10063) in early stacked 20s exposures and individual 60s exposures beginning 5 min after the trigger. At 3.62 min after the trigger, we measure the magnitude to be R = 17.7 +/- 0.1 relative to field stars and the USNO B1.0 catalog. Observations continued for 36 minutes.
GCN 10075 table
GRB_name GRB091024A
GCN_number 10075
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 10075 SUBJECT: GRB 091024: KAIT optical afterglow observations DATE: 09/10/25 02:54:09 GMT FROM: Ryan Chornock at UC Berkeley R. Chornock, W. Li, and A. V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory automatically responded to the Swift BAT trigger for GRB 091024 (Marshall et al., GCN 10062) with a sequence of observations starting 82 s after the BAT trigger. The afterglow is not initially detected. Our first detection of the optical afterglow (Mundell et al., GCN 10063) is in a 20 s I band observation starting at 08:58:45 UT. The KAIT position is (J2000) 22:36:59.64 +56:53:24.0 which is consistent the positions reported by Mundell et al. (GCN 10063) and Henden et al. (GCN 10073). The optical afterglow is thereafter detected in a sequence of V, I, and unfiltered images as it rose to a peak at an unfiltered magnitude of 16.2 (preliminarily calibrated to USNO-B1) at t=404s and then declined to mag 17.0 at t=988s, similar to the behavior described by Cano et al. (GCN 10066). After this time observations ceased due to a pointing limit.
GCN 10077 table
GRB_name GRB091024A
GCN_number 10077
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 10077 SUBJECT: GRB 091024: TLS Upper Limit DATE: 09/10/25 05:59:03 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, and U. Laux (TLS Tautenburg) report: We observed the afterglow of the ultra-long Swift/GBM GRB 091024 (Marshall et al., GCN 10062, Mundell et al., GCN 10063, Bissaldi & Connaughton, GCN 10070) with the 1.34m Schmidt telescope of the Thueringer Landessternwarte Tautenburg, Germany, 0.6 days after the GRB. We obtained 6 x 600 sec images in Rc. As a comparison star, we use the USNOB1.0 star at: RA (J2000) = 22:37:31.11 Dec. (J2000) = +56:59:26.23 which has R2 = 17.78 mag. This was one of the rare non-blended stars that was bright enough to be detected in the catalog. At the afterglow position, we do not detect any source which is not detected anyway in the DSS2 red plate. We place the following 2 sigma upper limit on the afterglow: dt Filter UL ____________________________________ 0.602309 Rc 21.0 and note that the true upper limit may be less deep due to crowding (the afterglow pretty much conincides with a ~20th mag object detected in the DSS). No further observations are planned. This message may be cited.
GCN 10078 table
GRB_name GRB091024A
GCN_number 10078
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 10078 SUBJECT: GRB091024 Swift/UVOT Upper Limits DATE: 09/10/25 11:05:38 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began observerving the field of GRB 091024 ~3ks after the BAT trigger (Marshall et al., GCN Circ. 10062). No optical afterglow is detected in the UVOT exposures at the refined position of the X-ray afterglow (Page et al., GCN Circ. 10069) and the position reported by Faulkes Telescope North (Mundell., et al., GCN Circ. 10063). The 3 sigma upper limits for the b, u, uvw2 and summed uvw1 exposures are reported below. Filter T_start(s) T_stop(s) Exposure(s) 3sigma Upper Limit ------------------------------------------------------------------- b 45981 45984 3 > 17.31 u 32984 33055 70 > 19.03 uvw1 26617 38935 1283 > 20.37 uvw2 3151 3161 10 > 17.28 ------------------------------------------------------------------- The above magnitudes are not corrected for the Galactic extinction corresponding to a significant reddening of E_{B-V} = 0.99 mag (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383,627).
GCN 10083 table
GRB_name GRB091024A
GCN_number 10083
Detection_method Konus-Wind Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 10083 SUBJECT: Konus-Wind and Konus-RF observations of GRB 091024 DATE: 09/10/26 17:18:48 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, and D. Svinkin on behalf of the Konus-Wind and Konus-RF teams, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 091024 (Swift-BAT trigger #373674: Marshall et al. GCN 10062, Sakamoto et al. GCN 10072) was observed by Konus-Wind in the waiting mode. The emission was detected in all three Konus-Wind energy bands: G1 (18-70 keV), G2 (70-360 keV) and G3 (360-1360 keV) with high S/N. The burst light curve shows three pulses: the first pulse starts at ~T0-10 s and has a duration of ~90 s, the second starts at ~T0+600 s and has a duration of ~100 s, and the most intense third pulse starts at T0+840 s and has a duration of ~400 s; there is a low-level emission between the first and second pulses. The most intense part of the third pulse was also detected by Konus-RF, while Coronas-F was exiting the SAA. The GBM localizations suggest a common origin of these events (Bissaldi & Connaughton, GCN 10070). Both the K-W light curve and the K-W ecliptic latitude response confirms this suggestion. So, we believe all these pulses belong to the extremely long burst, GRB 091024, which has a total duration of ~1200 s. Hence, some optical observations of this burst were performed during the most intense part of the prompt emission, but no bright optical flares have been reported. Modeling of the K-W 3-channel spectra by a power law with exponential cutoff model: dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep) yields the following parameters: -------------------------------------------------- Tstart Tstop alpha Ep (keV) -------------------------------------------------- P1 -7 80 -1.1+/-0.2 500+/-160 P2 606 703 -1.6+/-0.2 200+/-120 P3 835 1194 -1.4+/-0.2 230+/-50 Total -7 1194 -1.5+/-0.4 280+/-120 -------------------------------------------------- Tstart, Tstop - seconds since the BAT trigger time As observed by Konus-Wind, the burst had a fluence of (1.13 +/- 0.12)x10^-4 erg/cm2 (in the 20 - 1300 keV energy range). Assuming z = 1.092 (Cucchiara, Fox & Tanvir, GCN 10065) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M=0.27, Omega_\Lambda = 0.7, the isotropic energy release E_iso ~3.2x10^53 erg. All the quoted errors are estimated at the 1 sigma confidence level. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB091024/
GCN 10086 table
GRB_name GRB091024A
GCN_number 10086
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 10086 SUBJECT: GRB 091024: Burst was outside the Swift-BAT FOV after T0(BAT)+460sec DATE: 09/10/26 21:20:21 GMT FROM: Takanori Sakamoto at NASA/GSFC T. Sakamoto (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), on behalf of the Swift-BAT team: We reported the BAT refined analysis based on the event-by-event data only up to T+483 sec (T. Sakamoto et al., GCN Circ. GCN 10072). Since the Swift spacecraft slewed to the pre-planned target (GRB 091020) at T+415 sec, GRB 091024 became <5% coding by BAT at T+461 sec. This is the reason why we only have the mask-weighted light curve data up to T+483 sec. However, we do see the 2nd and 3rd episodes reported by Fermi-GBM (Bissaldi et al., GCN Circ. 10070) and by Konus-Wind and Konus-RF (Golenetskii et al., GCN Circ. 10083) in the BAT raw light curve data. Although we can not confirm whether these 2nd and 3rd episodes are associated with GRB 091024 by the BAT imaging capability, the BAT observations are consistent with the later peaks being part of GRB 091024.
GCN 10092 table
GRB_name GRB091024A
GCN_number 10092
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 10092 SUBJECT: GRB 091024: YNAO-GMG observations DATE: 09/10/27 12:12:05 GMT FROM: Jirong Mao at Yunnan Obs J. Mao (YNAO & INAF-OAB), S. Li and J. Bai (YNAO) report on behalf of the GMG group: We observed the optical afterglow of GRB 091024 (Marshall et al., GCN 10062) using one 2.4-m telescope located at Gao-Mei-Gu (GMG, Yunnan Observatory) about 3 hours after the trigger. Some preliminary results are shown below: Start UT Filter mag err ------------------------------------- 11:52:13 R 19.66 0.02 12:54:35 R 20.18 0.03 15:11:33 R 21.03 0.05 All the calibrations were processed by nearby USNO stars in the images and without extinction correction. The detailed analysis is ongoing. This message might be cited.
GCN 10093 table
GRB_name GRB091024A
GCN_number 10093
Detection_method Optical
redshift 1.0910
Circular_text TITLE: GCN CIRCULAR NUMBER: 10093 SUBJECT: GRB 091024: Keck/LRIS Spectroscopy DATE: 09/10/27 19:12:10 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (UC Berkeley), M. M. Kasliwal and S. R. Kulkarni (Caltech) report on behalf of a larger collaboration: We have obtained optical spectra of the afterglow of GRB091024 (Marshall et al., GCN 10062) with the Low Resolution Imaging Spectrometer mounted on the 10-m Keck I telescope. Observations began at 11:01 UT on 24 October 2009 (~ 2.1 hours after the burst) and covered the wavelength range from ~ 3500 - 10000 A. In addition to the features identified by Cucchiara, Fox, and Tanvir (CaII H & K, Mg I), we also find strong absorption features we identify as Mg II (2796 / 2803) and Fe II (2344, 2374, 2382, 2586, and 2600) at a common redshift of z = 1.091. The lack of Lyman-alpha absorption places an upper limit of z <~ 1.9 on the redshift of GRB091024.
GCN 10101 table
GRB_name GRB091024A
GCN_number 10101
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 10101 SUBJECT: GRB091024 optical observations DATE: 09/10/29 08:33:52 GMT FROM: Vladimir Sokolov at SAO RAS A. Moskvitin, T. Fatkhullin (SAO-RAS Niznijh Arkhyz, Russia), on behalf of a larger colaboration, report: We observed the field of the GRB 091024 afterglow (Marshall et al., GCN 10062) with the Zeiss-1000 telescope of SAO RAS, Russia. The observations were carried out starting from October, 24.651 (15:37 UT) till October, 24.976 (23:26 UT). In total 29 * 300 sec. exposures in the Rc-band and 29 * 300 sec. exposures in the V-band were obtained. During the observations we detected a faint fading object at the position reported by Mundell et al. (GCN 10063) as well as a small extended object with R~20.8 in ~2 arcseconds to the North-West from the afterglow (see also Kann and Laux GCN 10077). The brightness of the OT in the first stacked R-band images (the mean epoch is 16:52 UT) is R = 20.7 +/- 0.2 (we admit some contribution in flux from the extended object). It is not clear at this stage if the extended object is a host galaxy or a foreground galaxy responsible for the absorption line system reported by Cucchiara et al. (GCN 10065) and Cenko et al. (GCN 10093). The data analysis is in progress. Photometry was carried out using nearby USNO B1.0 stars (R2 magnitudes). This message may be cited.
GCN 10114 table
GRB_name GRB091024A
GCN_number 10114
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 10114 SUBJECT: GRB 091024: Fermi LAT upper limits DATE: 09/10/30 19:29:08 GMT FROM: Aurelien Bouvier at Stanford Aurelien Bouvier (SLAC), Julie McEnery (NASA/GSFC), Jim Chiang (SLAC), Dan Kocevski (SLAC), Elena Moretti (INFN Trieste), Vlasios Vasileiou (NASA/GSFC & UMBC) and Frederic Piron (LPTA) report on behalf of the Fermi LAT team: We present the flux and fluence upper limits based on the non- detection of GRB 091024 (trigger 278067360 / 091024372) by the Fermi Large Area Telescope (Fermi LAT) in the 0.1-300 GeV energy range. This burst was detected by Swift (GCN 10062) and the Fermi Gamma-ray Burst Monitor with a first emission interval lasting ~50 sec and a second emission interval starting ~630 sec after trigger and lasting more than 400 sec (GCN 10070). The spacecraft performed a repointing maneuver for this burst which resulted in pointed observation for 5 hours starting ~350 sec after trigger. No significant emission was detected in the LAT energy range during any of the time intervals in which the burst was in the LAT field of view. We computed the 95% CL upper limits using a bayesian method (Helene O., 1983, N.I.M. 212, 319) and our background estimation tool (described in Abdo et al. 2009: arXiv:0910.4192) on the LAT energy flux and fluence for the time interval T0+350 to T0+2000 sec with respect to the GRB trigger time T0 (08:55:58.47 UT, October 24th 2009) and with an assumed spectral index of -2.2: - 95% Energy Flux Upper Limit = 9.4e-10 erg/cm^2/sec - 95% Energy Fluence Upper Limit = 1.5e-6 erg/cm^2 The upper limit results presented above are preliminary; final results will be published in the Fermi LAT GRB Catalog. 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.
GCN 10116 table
GRB_name GRB091024A
GCN_number 10116
Detection_method Optical
redshift 1.0910
Circular_text TITLE: GCN CIRCULAR NUMBER: 10116 SUBJECT: GRB 091024: optical observations DATE: 09/11/01 22:00:15 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, V. Biryukov (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 091024 (Marshall et al., GCN 10062) with ZTE telescope of Crimean branch of SAI MSU in R-filter on Oct.24 between (UT) 16:18:50 - 00:04:47 and Oct.25 19:07:19 - 19:48:19 under moderate seeing of about 3". In initial images we detect fading afterglow (Mundell et al., GCN 10063). In a combined image of the Oct. 24 the afterglow looks like extended due to the nearby NW object reported by Moskvitin et al. (GCN 10101). In a preliminary data reduction we do not separate afterglow and nearby object. The astrometry of the afterglow + nearby object is following Oct.24 RA(J2000): 22 36 59.61 Dc(J2000): +56 53 23.1 with uncertainty of 0.5 arcsec Oct.25 RA(J2000): 22 36 59.33 Dc(J2000): +56 53 24.5 with uncertainty of 0.5 arcsec The coordinates of Oct. 24 consistent with afterglow coordinates (Mundell et al., GCN 10063, Henden et al. GCN 10073, Chornock et al. GCN 10075). The angular distance between astrometry results is 2.7" suggests a prevalence of the afterglow on Oct.24 and nearby object on Oct.25. Taking into account the redshift of z = 1.091 (Cucchiara et al. GCN 10065, Cenko et al. GCN 10093) one can estimate the distance between afterglow and object as 22 kpc and the nearby object could be the host galaxy of GRB 091024 as suggested early (Moskvitin et al. GCN 10101). A preliminary photometry of the afterglow+nearby object is based on reference star USNO B1.0 1468-0448529 (22 36 55.66 +56 53 04.2) assuming R=17.30: T0+ Filter, Exposure, mag., err. (d) (s) 0.3210 R 600 18.31 +/-0.07 0.3283 R 600 18.56 +/-0.08 0.3356 R 600 18.72 +/-0.08 0.3429 R 600 18.56 +/-0.08 0.3522 R 600 18.73 +/-0.08 0.3595 R 600 18.80 +/-0.09 0.3668 R 600 18.89 +/-0.11 0.3741 R 600 18.70 +/-0.08 0.3814 R 600 19.20 +/-0.16 0.3887 R 600 19.16 +/-0.16 0.3960 R 600 18.86 +/-0.15 0.4076 R 780 19.44 +/-0.34 0.5706 R 1260 19.11 +/-0.08 0.5873 R 1320 19.15 +/-0.09 1.4386 R 2340 20.7 +/- 0.2 We caution that afterglow photometry above is contaminated by the nearby object which we suggest as a candidate of host galaxy. The combined image can be found at http://grb.rssi.ru/GRB091024/GRB091024a_091024_R_ZTE.gif where vertical tick points out the afterglow and horizontal one points out the nearby object.