//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15282 SUBJECT: GRB 131002A: Faulkes Telescope North optical afterglow DATE: 13/10/02 07:17:47 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara) on behalf of a large collaboration reports: The 2-m Faulkes Telescope North automatically began observing GRB 131002A on October 02 2013 at 06:57:26 UT (~3.1 min after the burst trigger). Within the XRT error circle we find a fading uncatalogued object at coordinates RA(2000.0)= 16:52:52.86 Dec(2000.0)= +82:03:16.4 (error 0.5") with R=15.2 +- 0.2 mag, calibrated against nearby USNOB-1 stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15283 SUBJECT: GRB 131002A: Swift detection of a burst DATE: 13/10/02 07:49:31 GMT FROM: Caryl Gronwall at PSU/Swift-UVOT B. N. Barlow (High Point University), V. D'Elia (ASDC), P. A. Evans (U Leicester), C. Gronwall (PSU), A. Y. Lien (NASA/GSFC/ORAU), D. Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), T. Sakamoto (AGU), M. H. Siegel (PSU) and M. C. Stroh (PSU) report on behalf of the Swift Team: At 06:54:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 131002A (trigger=572721). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 253.275, +82.057 which is RA(J2000) = 16h 53m 06s Dec(J2000) = +82d 03' 26" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed two pulses with total duration of ~50 seconds. The first pulse happened at T0 lasting around 2 seconds, with peak count rate of ~3000 counts/sec (15-350 keV). The second pulse happened at ~T+45 with a duration of around 15 seconds and peak count rate ~2000 counts/sec (15-350 keV). The XRT began observing the field at 06:55:27.9 UT, 66.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 253.2159, 82.0536 which is equivalent to: RA(J2000) = 16h 52m 51.83s Dec(J2000) = +82d 03' 13.0" with an uncertainty of 2.0 arcseconds (radius, 90% containment). This location is 31 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 in excess of the Galactic value (5.56 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.6 (+1.37/-1.25) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 9.38e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 869 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. 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. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.08. Burst Advocate for this burst is B. N. Barlow (bbarlow AT highpoint.edu). 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.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15287 SUBJECT: GRB 131002A: Enhanced Swift-XRT position DATE: 13/10/02 15:52:22 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 1599 s of XRT Photon Counting mode data and 3 UVOT images for GRB 131002A, 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 = 253.22092, +82.05433 which is equivalent to: RA (J2000): 16h 52m 53.02s Dec (J2000): +82d 03' 15.6" with an uncertainty of 1.8 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, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15290 SUBJECT: GRB 131002A: ISON-NM optical observations DATE: 13/10/02 19:06:52 GMT FROM: Alexei Pozanenko at IKI, Moscow L. Elenin (KIAM), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed optical transient(Guidorzi et al., GCN 15282) of the Swift GRB 131002A (Barlow et al., GCN 15283) with 0.4-m SANTEL-400AN telescope of ISON-NM observatory starting on Oct., 2 (UT) 06:55:23 (i.e. 58 s after burst trigger) in robotic mode. Series of 30 s exposures were obtained in clear filter. After PSF subtraction of a nearby bright star we clearly detect the optical transient in each single frames of initial series. Coordinates of the optical transient are (J2000) 16 52 53.29 +82 03 15.6 with uncertainty of 0.25" in both coordinates. Preliminary photometry is based on USNO-B1.0 (R2) stars. The maximum brightness of the OT (15.2 +/- 0.05) was detected in the second frame at 0.00141 days after trigger. Light curve of the initial stage of the OT can be found at http://grb.rssi.ru/GRB131002A/GRB131002A_ISON-NM_lc.png //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15292 SUBJECT: GRB 131002A: Swift-XRT refined Analysis DATE: 13/10/02 19:30:03 GMT FROM: Phil Evans at U of Leicester K.L. Page (U. Leicester), C. Pagani (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester) and report on behalf of the Swift-XRT team: report on behalf of the Swift-XRT team: We have analysed 6.5 ks of XRT data for GRB 131002A, from 56 s to 29.9 ks after the BAT trigger. The data comprise 44 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The late-time light curve (from T0+5.1 ks) can be modelled with a power-law decay with a decay index of alpha=1.05 (+0.26, -0.24). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.03 (+0.19, -0.18). The best-fitting absorption column is 1.0 (+0.5, -0.4) x 10^21 cm^-2, in excess of the Galactic value of 5.6 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.0 (+0.5, -0.4) x 10^21 cm^-2 Galactic foreground: 5.6 x 10^20 cm^-2 Excess significance: 1.9 sigma Photon index: 2.03 (+0.19, -0.18) If the light curve continues to decay with a power-law decay index of 1.05, the count rate at T+24 hours will be 7.7 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x 10^-13 (3.6 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00572721. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15294 SUBJECT: GRB 131002A: Swift/UVOT Detection DATE: 13/10/03 11:42:38 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and B. N. Barlow (High Point University) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 131002A 77 s after the BAT trigger (Barlow et al., GCN Circ. 15283). A fading source consistent with the optical position (Guidorzi GCN Circ. 15282) is detected in the initial UVOT exposures. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 77 227 147 17.94 ± 0.06 white 870 1020 147 19.40 ± 0.11 v 620 1071 59 18.89 ± 0.36 b 546 739 39 19.41 ± 0.31 u 290 7169 736 >21.1 w1 669 6964 510 >20.7 m2 645 13293 939 >21.1 w2 770 11860 1199 >21.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.08 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15300 SUBJECT: GRB 131002A: Fermi GBM observation DATE: 13/10/04 15:44:29 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 06:55:06.99 UT on 2 October 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131002A (trigger 402389709 / 131002288) which was also detected by the Swift/BAT (Barlow et al. 2008, GCN 15283). GBM triggered ~46 sec later than Swift/BAT on the second pulse of the GRB. The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 128.2 degrees. The GBM light curve shows a single pulse with a duration (T90) of about 12 s (50-300 keV). The time-averaged spectrum from T0-4.096 s to T0+4.096 s is well fit by a simple power law function with index -1.6 +/- 0.1 keV. The event fluence (10-1000 keV) in this time interval is (1.4 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0 -2.1 s in the 10-1000 keV band is 2.1 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15302 SUBJECT: GRB 131002A, Swift-BAT refined analysis DATE: 13/10/04 20:40:57 GMT FROM: Amy Lien at GSFC T. Sakamoto (AGU), B. N. Barlow (High Point University), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), J. Norris (BSU), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (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 131002A (trigger #572721) (Barlow, et al., GCN Circ. 15283). The BAT ground-calculated position is RA, Dec = 253.103, 82.036 deg which is RA(J2000) = 16h 52m 24.8s Dec(J2000) = +82d 02' 08.3" with an uncertainty of 3.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%. The mask-weighted light curve shows two peaks separated by ~45 seconds. The first short peak starts at ~T0 and lasts for ~1 sec, the second long peak starts at ~T+40 and ends at ~T+60. T90 (15-350 keV) is 55.59 +- 3.98 sec (estimated error including systematics). The spectral lag for the first short pulse is 0.114 s +- 0.04 s (for the 50-100 keV and 15-25 keV bands), and the spectrum is slightly softer than the second long pulse. Therefore, the spectral and timing properties match better to those of regular long bursts than those normally seen in short bursts with extended emission. The time-averaged spectrum from T-0.20 to T+59.67 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.63 +- 0.19. The fluence in the 15-150 keV band is 6.4 +- 0.8 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+43.17 sec in the 15-150 keV band is 1.3 +- 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/572721/BA/