//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15332 SUBJECT: GRB 131014A: Fermi GBM detection DATE: 13/10/14 13:13:57 GMT FROM: Gerard Fitzpatrick at UCD G. Fitzpatrick (UCD) and S. Xiong (UAH) report on behalf of the Fermi GBM Team: At 05:09:00.20 UT on 14 October 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131014A (trigger 403420143/131014215). High peak flux from the GRB caused GBM to issue a repoint request that reoriented the satellite to place the GRB near the LAT boresight for 2.5 hours, subject to Earth limb contraints. The on-ground calculated location, using the GBM trigger data, is RA = 101.9 , DEC = -20.0 (J2000 degrees, equivalent to 06h 47m, -20d 0.0'), with an uncertainty of 1.00 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 71.9 degrees. The GBM light curve consists of a single peak with a duration (T90) of about 3.2 s (50-300 keV). The event fluence (10-1000 keV) in this time interval is 1.9E-4 +/- 2E-7 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.3 s in the 10-1000 keV band is 311.5 +/- 1.3 ph/s/cm^2. The time-averaged spectrum from T0-1.0 s to T0+4.2 s is adequately fit by a Band function with Epeak = 318 +/- 3 keV, alpha = -0.34 +/- 0.01, and beta = -2.58 +/- 0.02 The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15333 SUBJECT: GRB 131014A: Fermi-LAT detection DATE: 13/10/14 17:23:36 GMT FROM: Elisabetta Bissaldi at U.Innsbruk/IAPP R. Desiante (University of Udine and INFN Trieste), D. Kocevski(NASA/Goddard), G. Vianello (Stanford), F.Longo, E.Bissaldi (University and INFN Trieste) and E.Troja (NASA/GSFC/CRESST) report on behalf of the Fermi-LAT team: At 05:09:00.20 on 2013-10-14 Fermi LAT detected high energy emission from GRB 131014A, which was also detected by Fermi-GBM (G. Fitzpatrick and S. Xiong, GCN 15332). The best LAT on-ground location is found to be RA, DEC 100.5, -19.1 (J2000) with an error radius of 0.45 deg (68% containment, statistical error only). This was at the edge of the field of view of the LAT at the time of the trigger (~70 deg away from the instrument axis). The burst triggered an autonomous repoint of the spacecraft, which moved it well within the LAT field-of-view for an additional 500s, before the source was occulted by the Earth. Due to the large angle at which the burst was observed during most of the exposure, we expect a systematic error on the position of up to 0.5 deg. This is due to the fact that the reconstruction of the direction of incoming photons is biased toward the axis of the instrument for sources at very large off-axis angles. More than 7 photons above 100 MeV and 3 photons above 1 GeV are observed within 100 seconds. The highest energy photon is a 1.8 GeV event which is observed ~15 seconds after the GBM trigger. A single peaked emission lasting roughly 5 seconds can be seen using the non-standard LAT Low Energy (LLE) with a significance of ~23 sigma. A Swift ToO request for this burst has been submitted and approved. The Fermi LAT point of contact for this burst is Rachele Desiante (rachele.desiante@ts.infn.it). 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15334 SUBJECT: GRB 131014A Tiled Swift observations DATE: 13/10/14 17:26:27 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the Fermi/LAT GRB 131014A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00019 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the Fermi/LAT event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; and 2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15335 SUBJECT: GRB 131014A: Swift detection of a possible X-ray afterglow DATE: 13/10/14 22:10:16 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. A. Kennea (PSU) and Alex Amaral-Rogers (U Leicester) report on behalf of the Swift/XRT team On October 14, 2013 at 17:24 UT, Swift began a series of target of opportunity observations to cover the region around GRB131014A (Fitzpatrick et al., GCN #15332, Evans, GCN #15334), approximately 12.3 hours after the burst was detected by Fermi. In Swift/XRT Photon Counting mode data we detect an uncatalogued point source at the following location: RA/Dec(J2000) = 100.30064, -19.09711, which is equivalent to: RA(J2000) = 06h 41m 12.2s Dec(J2000) = -19d 05m 49.6s with an estimated uncertainty of 4.4 arc-seconds radius (90% containment). This position is 11.3' from the LAT position reported by Desiante et al. (GCN #15333). The source brightness is 0.07 +/- 0.01 XRT count/s. We cannot yet confirm whether this source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15336 SUBJECT: GRB 131014A: Nanshan optical observations DATE: 13/10/14 23:52:12 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), X. Zhang, G.-J. Feng, A. Esamdin, L. Ma (XAO) report: We observed the XRT field (Kennea et al., GCN 15335), which contains an uncatalogued point source as the possible X-ray afterglow of GRB 131014A (Fitzpatrick et al., GCN 15332; Desiante et al., GCN 15333), using the 1m telescope located Mt. Nanshan, Xinjiang, China. We obtained 2x600s R-band images at a high airmass of ~2.4 and at the mean time of 2013-10-14 22:52:52 UT (i.e., 17.73 hr after the Fermi trigger). A faint source is marginally detected at the North-West border of the XRT error circle in Kennea et al. (GCN 15335) in the stacked image, and its position is consistent with that of the object already present in the DSS finding chart at coordinates R.A. (J2000) = 06:41:11.950 Dec. (J2000) = -19:05:46.94 However, the seemingly extended structure of the object within the XRT error in the DSS chart is not present in our image, which sets a constraint of R > ~20.5 mag for any source within the XRT error circle, calibrated with nearby USNO B1 field. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15337 SUBJECT: GRB 131014A: NOT afterglow candidate DATE: 13/10/15 07:21:29 GMT FROM: Steve Schulze at U of Iceland S. Schulze (PUC, MCSS), D. Xu , D. Malesani, J. P. U. Fynbo (DARK/NBI), T. Kangas (NOT), H. Ghasemi, A. Takalo, C. Xavier, Y. Litus, J. Saario, T. Tuominen, J. Harmanen, and M. Khansari (Tuorla Observatory) report on behalf of a large collaboration: We observed the field of GRB 131014A (Fitzpatrick & Xiong, GCN15332; Desiante et al., GCN 15333) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 6 x 300 s R-band images. The mean time of the NOT observation is October 15.221 UT, 1.01 days after the Fermi trigger. We detect an uncatalogued source within the error circle of the possible X-ray afterglow (Kennea et al., GCN 15335) at: R.A.(J2000) = 06:41:12.240 Dec. (J2000) = -19:05:51.49 with an uncertainty of 0.4''. This source may be the optical afterglow of GRB 131014A, but we cannot presently assess its variability and thus confirm its nature. We measure a R1 magnitude of 23.11 +/- 0.12 mag calibrated against four USNO B1 stars (0709-0091487, 0708-0089714, 0709-0091459, 0709-0091432). We also note the presence of a brighter source (R.A. = 06:41:12.1, Dec. = -19:05:47.6) just to the North of the XRT error circle, which is however detected in the SDSS r-band frames. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15338 SUBJECT: Konus-Wind observation of GRB 131014A DATE: 13/10/15 07:56:52 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long-duration very bright GRB 131014A (Fermi GBM detection: Fitzpatrick & Xiong, GCN 15332; Fermi LAT detection: Desiante et al., GCN 15333) triggered Konus-Wind at T0=18541.405 s UT (05:09:01.405). The light curve shows multiple bright, overlapped pulses from ~T0 s to ~T0+6~s. The emission at this phase of the event is seen up to ~12 MeV. The burst was followed by a ~150s-long decaying tail of a weak, soft, extended emission. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB131014_T18541/ As observed by Konus-Wind, the burst had a fluence of (2.05 ± 0.03)x10-4 erg/cm2, and a 64-ms peak flux, measured from T0+1.664 s, of (2.10 ± 0.04)x10-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+12.288 s) is best fit in the 50 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.79 ± 0.04, the high energy photon index beta = -2.89 ± 0.08, the peak energy Ep = 346 ± 9 keV, chi2 = 118/94 dof. The spectrum near the maximum count rate (measured from T0+1.536 s to T0+1.792 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.42 ± 0.07, the high energy photon index beta = -2.87 ± 0.13, the peak energy Ep = 607 ± 25 keV, chi2 = 77.5/77 dof. All the quoted results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15339 SUBJECT: GRB 131014A: Enhanced XRT position DATE: 13/10/15 13:18:11 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) and A. Amral-Rogers (U. Leicester) report on behalf of the Swift-XRT team: Using 1.7 ks of XRT Photon Counting mode data and 5 UVOT images for GRB 131014A, 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 = 100.30220, -19.09781 which is equivalent to: RA (J2000.0) = 06h 41m 12.53s Dec (J2000.0) = -19d 05' 52.1" with an uncertainty of 2.3 arcsec (radius, 90% confidence). This position is 5.9 arcsec from the initial XRT position reported by Kennea & Rogers (GCN 15335) and 11.2 arcmin from the LAT position (Desiante et al. (GCN 15333), but 4.1 arcsec from the NOT optical position of Schulze et al (GCN 15337). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15340 SUBJECT: GRB 131014A: RATIR Optical and NIR Observations DATE: 13/10/15 17:19:59 GMT FROM: Eleonora Troja at GSFC E. Troja (GSFC), Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 131014A (Fitzpatrick et al., GCN 15332, Desiante, et al., GCN 15333) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/10 15.36 to 2013/10 15.52 UTC (27.45 to 31.41 hours after the GBM trigger), obtaining a total of 2.84 hours exposure in the r and i bands, 1.19 hours exposure in the Z and Y bands, and 1.09 hours exposure in the J and H bands. For a source within the Swift-XRT error circle (Kennea et al. GCN 15335), in comparison with 2MASS, we obtain the following measurements: r 23.42 ± 0.21 i 22.76 ± 0.17 Z 23.1 ± 0.4 (2.7 sigma) Y 21.20 ± 0.27 J 21.9 ± 0.6 (1.8 sigma) H 21.8 ± 0.7 (1.6 sigma) These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The object is located 0.4 arcsec from the NOT afterglow candidate (Schulze et al., GCN 15337) and consistent with it. We cannot determine whether the source is fading. No other uncatalogued source is detected within the XRT error circle. Despite the large errors, our preliminary analysis indicates a blue continuum in YJH, suggestive of a possible z-band dropout, and implying a high-redshift (z ~ 6) for GRB 131014A. Further observations are planned. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15342 SUBJECT: GRB 131014A: Swift/UVOT Upper Limits DATE: 13/10/15 20:59:52 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and Alex Amaral-Rogers (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began observations of the field of GRB 131014A starting approximately 45.7 ks after the Fermi LAT detection (Desiante et al. 2013, GCN 15333). We do not detect any new source consistent with the NOT afterglow candidate (Schulze et al. 2013, GCN 15337). Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the summed exposures are presented below. ---------------------------------------------------- Filter TSTART TSTOP Exposure Mag ---------------------------------------------------- u 45,688 74,324 1239 >20.9 ---------------------------------------------------- The quoted upper limits have not been corrected for the expected extinction due to the Galactic reddening along the line of sight to this burst of E(B-V) = 0.22 mag (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15344 SUBJECT: GRB 131014A: Swift-XRT refined Analysis DATE: 13/10/16 11:06:55 GMT FROM: Kim Page at U.of Leicester A. Amaral-Rogers, P.A. Evans & K.L. Page (U.Leicester) report on behalf of the Swift-XRT team: We have analysed 11 ks of XRT data for the Fermi/LAT-detected burst: GRB 131014A, from 44.1 ks to 173.4 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. An X-ray source is detected within the Fermi/LAT error circle. The enhanced XRT position was given in GCN Circ. 15339 (Evans & Amaral-Rogers). The light curve can be modelled with a power-law decay with a decay index of alpha=1.53 (+/-0.28). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.2 (+0.7, -0.6). The best-fitting absorption column is 6.8 (+4.0, -3.0) x 10^21 cm^-2, in excess of the Galactic value of 2.2 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (8.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.8 (+4.0, -3.0) x 10^21 cm^-2 Galactic foreground: 2.2 x 10^21 cm^-2 Excess significance: 2.5 sigma Photon index: 2.2 (+0.7, -0.6) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020300. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15346 SUBJECT: GRB 131014A: RATIR Optical/NIR Afterglow Confirmation DATE: 13/10/16 22:34:10 GMT FROM: Eleonora Troja at GSFC Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We reobserved the field of GRB 131014A (Fitzpatrick, et al., GCN 15332; Desiante, et al., GCN 15333) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/10 16.36 to 2013/10 16.52 UTC (51.38 to 55.33 hours after the GBM trigger), obtaining a total of 2.11 hours exposure in the r and i bands and 0.88 hours exposure in the Z, Y, J, and H bands. We do not detect the source reported in Troja et al. (GCN 15340). In comparison with SDSS DR9 and 2MASS, we obtain the following upper limits (3-sigma): r >23.8 i >23.4 Z >22.4 Y >21.7 J >21.4 H >20.9 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We note that the source reported in Troja et al. (GCN 15340) lies within the XRT localization reported in Kennea et al. (GCN 15335), but is ~4 arcsec offset from the XRT enhanced position (Evans et al., 15339). However, the source shows evidence of fading in our latest exposures (>3 sigma level, i band; 2-sigma level, r and Y band), suggesting that it is associated with GRB131014A. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15347 SUBJECT: GRB 131014A: GROND observations DATE: 13/10/17 07:11:16 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann (MPE Garching), T. Kruehler (ESO), K. Varela and J. Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of the Fermi GBM/LAT GRB 131014A (Fitzpatrick & Xiong, GCN #15332) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory (Chile). Observations started at 07:07 UT on 16 October 2013, 2.08 days after the GRB. They were performed at an average seeing of 1".0 and at an average airmass of 1.1. Observations were slightly affected by passing clouds. We obtained a total exposure of 4500 sec in g'r'i'z' and 3600 sec in JHK. We detect several sources in and near the refined XRT error circle by Evans & Amral-Rogers (GCN #15339). Source 1 is the one reported by Schulze et al. (GCN #15337), also detected by Troja et al. (GCN #15340) and claimed to be fading by Troja et al. (GCN #15346). We estimate preliminary magnitudes and upper limits (all in the AB system) in an aperture of 1".8: g' = 24.1 ± 0.2 mag r' = 22.8 ± 0.1 mag, i' = 22.5 ± 0.1 mag, z' = 22.2 ± 0.1 mag, J > 21.5 mag, H > 21.0 mag, K > 19.4 mag This source lies significantly outside the refined XRT error circle (Evans & Amral-Rogers, GCN #15339), is extended in our images and we find no evidence of fading as compared to the earlier (t = 1 day) measurement of Schulze et al. (GCN #15337), also using image subtraction versus the NOT image. We thus do not consider it the afterglow of GRB 131014A. The colors and the apparent extent of the source are consistent with a low-redshift galaxy. Source 2 is consistent with being point-like in our images and found at: RA (J2000) = 06:41:12.41 Dec. (J2000) = -19:05:53.5 We estimate preliminary magnitudes and upper limits (all in AB) for a point source of: g' > 25.0 mag r' = 24.8 ± 0.3 mag, i' = 23.8 ± 0.2 mag, z' = 22.8 ± 0.1 mag, J = 21.7 ± 0.2 mag, H = 21.6 ± 0.4 mag, K > 19.8 mag This source is extremely red and lies on the edge of the refined XRT error circle. Source 3 also lies on the edge of the error circle at RA (J2000) = 06:41:12.56 Dec. (J2000) = -19:05:50.1 We estimate preliminary magnitudes and upper limits (all in AB) for a point source of: g' = 25.1 ± 0.4 mag r' = 24.5 ± 0.2 mag, i' = 24.1 ± 0.2 mag, z' = 23.8 ± 0.3 mag, J > 22.0 mag, H > 21.5 mag, K > 19.8 mag, At present, no statement about variability for either source 2 or 3 can be made. Magnitudes are calibrated against SDSS (griz) and 2MASS (JHK) stars, and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.26 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15348 SUBJECT: GRB 131014A: Suzaku WAM observation of the prompt emission DATE: 13/10/17 10:20:56 GMT FROM: Takafumi Kawano at Hiroshima U/Suzaku-HXD-WAM T. Kawano, M. Ohno, K. Takaki, R. Nakamura, S. Furui, Y. Fukazawa(Hiroshima U.), T. Yasuda, M. Tashiro, Y. Terada, Y. Ishida, H. Ueno, S. Sugimoto (Saitama U.), M. Yamauchi, N. Ohmori, M. Akiyama (Univ. of Miyazaki), K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report: The bright, long GRB 131014A (Fermi GBM detection: Fitzpatrick & Xiong, GCN 15332; Fermi LAT detection: Desiante et al., GCN 15333) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at UT 05:09:0.269(=T0). The observed light curve shows a bright peak followed by a weaker emission seen up to T0+5 s with a duration (T90) of about 3 seconds. The fluence in 100 - 1000 keV was 2.02 (-0.11, +0.39) x10^-4 erg/cm^2. The 1-s peak flux measured from T0+1.6 s was 270 (-28, +34) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0 s to T0+5 s is well fitted by a GRB Band model as follows. the low-energy photon index alpha: -0.81 (-0.85, +1.16), the high-energy photon index beta: -2.95 (-0.40, +0.18), and the peak energy Epeak: 285 (-88, +33) keV, (chi^2/d.o.f = 24.3/23). All the quoted errors are at statistical 90% confidence level. The light curves for this burst will be available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15351 SUBJECT: GRB 131014A: XRT position information DATE: 13/10/18 13:30:03 GMT FROM: Phil Evans at U of Leicester P.A. Evans and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team The Swift-XRT localisation of GRB 131014A has unusually significant uncertainty, which is not included in the positions previously circulated (GCNs 15335, 15339), or on the website. The afterglow was detected towards the edge of two of the initial tiled pointings, and near the centre of a dedicated follow-up pointing. Positions derived from these individual pointings vary by up to 4" when the Swift star tracker attitude is used. If we instead create enhanced positions (using the UVOT to derive the astrometry) we find astrometric corrections of ~5-8", although we find significant variation between these corrections. This suggests that there is some degeneracy in the aspect solution. Given this variation we suggest that the XRT position should be assumed to have an uncertainty of 6", rather than the values previously announced or posted online. Thus the best available XRT position is RA, Dec=100.3033, -19.0971, which is equivalent to: RA: 06h 41m 12.80s Dec: -19° 05′ 49.6′′ with an uncertainty of approx 6". This is the enhanced position derived from the follow-up observation, which was centred on the afterglow. Some low-level scatter in the aspect solutions is seen in all enhanced positions, and is calibrated into our enhanced position errors. GRB 131014A shows an exceptionally large scatter in the aspect solutions which is not currently understood. Futhermore, as this is a late-time tiled follow up, where the source is faint and individual exposures are short, the normal mechanisms which remove outlying aspect solutions cannot be applied. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15363 SUBJECT: IPN Triangulation of GRB 131014A DATE: 13/10/21 16:02:54 GMT FROM: Dmitry Svinkin at Ioffe Institute K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, and V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi GBM team, report: The long-duration, intense GRB 131014A (GCN 15332, 15338, 15348) was observed by Fermi (GBM: trigger 403420143), Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), Suzaku (WAM), and MESSENGER (GRNS), at about 18540 s UT (05:09:00). The burst was outside the coded field of view of the BAT. The burst was localized by the Fermi-LAT to a 2290 sq. arcmin. error circle (1 sigma, GCN 15333), and the X-ray afterglow was found by the Swift-XRT (GCN 15335). We have triangulated it to a 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 100.286 (06h 41m 09s) -19.130 (-19d 07' 49") Corners: 100.122 (06h 40m 29s) -19.544 (-19d 32' 39") 100.356 (06h 41m 25s) -19.177 (-19d 10' 38") 100.448 (06h 41m 48s) -18.714 (-18d 42' 52") 100.215 (06h 40m 52s) -19.083 (-19d 05' 00") --------------------------------------------- The error box area is 251 sq. arcmin, and its maximum dimension is 53 arcmin (the minimum one is 10 arcmin). The box area is about 10 times smaller than that of the LAT error circle (2290 sq. arcmin.). The reported Swift-XRT source (GCN 15339) is inside the box. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB131014_T18541/IPN/ Some improvement in this triangulation is possible. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15364 SUBJECT: GRB 131014A: RATIR Optical/NIR Afterglow Retraction DATE: 13/10/21 23:39:18 GMT FROM: Eleonora Troja at GSFC Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We reobserved the field of GRB 131014A (Fitzpatrick, et al., GCN 15332; Desiante, et al., GCN 15333) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from from 2013/10 17.36 to 2013/10 17.53 UTC (75.50 to 79.48 hours after the GBM trigger), and again the next night from 2013/10 18.35 to 2013/10 18.53 UTC (99.18 to 103.48 hours after the GBM trigger), obtaining a total of 2.3 hours exposure in the r and i bands and 1.0 hours exposure in the Z, Y, J, and H bands each night. These observations reach similar depths to prior RATIR observations of the field (Troja, et al., GCNs 15340, 15346) in which we report a candidate optical/NIR afterglow, albeit with marginal statistical significance. Although the optical/NIR candidate afterglow appears fainter in the 2nd and 3rd nights relative to our 1st night, it is similarly bright in the 4th night as on the 1st night. The co-addition of data from nights 2 through 4 yields flux levels (in all bands) statistically consistent with those measured on night 1. An image subtraction analysis confirms this result. We conclude that our source is not the optical/NIR afterglow of GRB 131014A. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.