//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15328 SUBJECT: GRB 131011A: GROND afterglow observations DATE: 13/10/13 07:41:49 GMT FROM: Vladimir Sudilovsky at MPE V. Sudilovsky, M. Tanga, and J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 131011A (Kasliwal et al., GCN #15324) 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 03:30 UT on 13 October 2013. They were performed at an average seeing of 1.3" and at and average airmass of 1.2. We find the afterglow candidate reported by Kasliwal et al. Based on the first 1500 sec g'r'i'z' and 1200 sec JHK exposure, we estimate preliminary magnitudes (all in AB) of g' = 21.9 ± 0.1 mag r' = 21.7 ± 0.1 mag, i' = 21.5 ± 0.1 mag, z' = 21.3 ± 0.1 mag, J = 21.1 ± 0.1 mag, H = 20.5 ± 0.2 mag, K = 20.2 ± 0.4 mag, Magnitudes are calibrated against nearby SDSS (griz) and 2MASS (JHK) stars, and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.02 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15331 SUBJECT: GRB 131011A: Fermi GBM detection DATE: 13/10/14 00:09:15 GMT FROM: Peter Jenke at MSFC P. Jenke (UAH) reports on behalf of the Fermi GBM Team: At 17:47:34.99 UT on October 11 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131011A (trigger 403206457/131011741). A candidate optical afterglow was found by iPTF (Kasliwal et al. 2013, GCN 15324) using the GBM on-ground location. Additional follow-ups confirmed that the optical source has faded (Xu et al. 2013, GCN 15325) and has a redshift of z = 1.874 (Rau et al. 2013, GCN 15330). A weak X-ray source consistent with the optical afterglow was detected by the Swift XRT (Page et al. 2013, GCN 15329). The angle of the burst direction to the Fermi LAT boresight is 74 degrees. The GBM light curve consists of one main peak and a small post burst with a combined duration (T90) of about 77 s (50-300 keV). The time-averaged spectrum from T0-3 s to T0+25s is well fit by a Band function with Epeak of 220 +/- 30 keV. Alpha = -0.79 +/- 0.08 and Beta = -2.0 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (6.60 +/- 0.03)E-05 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+4.3 s in the 10-1000 keV band is 4.3 +/- 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: 15341 SUBJECT: Fermi 403206457 / GRB 131011A: AAO optical observations DATE: 13/10/15 18:50:42 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V. Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical afterglow (Kasliwal et al. 2013, GCN 15324; Xu et al. 2013, GCN 15325; Perley et al. 2013, GCN 15327; Sudilovsky et al. 2013, GCN 15328) of Fermi trigger 403206457 / GRB 131011A (Jenke, GCN 15331) with AS-32 (0.7m) telescope of Abastumani Observatory on Oct. 12 starting (UT) 22.32. We obtained several unfiltered images of 120 s exposure. The optical afterglow is clearly visible in a stacked image in coordinates (J2000) RA= 02 10 06.32 Dec= -04 24 40.5 (uncertainty of 0.33 arcseconds on both axes) which is coincide with position reported by Kasliwal et al. (GCN 15324). The photometry of combined image against nearby SDSS stars reported by Xu et al. (GCN 15325), R magnitude, transformed by Lupton gri -> R transformation is following: Date T_start t-t0, exp, OT (UT) mid, d s 2013-10-12 22:32:33 1.2218 26x120 21.33 +/- 0.09 A finding chart can be found at http://grb.rssi.ru/GRB131011A/GRB131011A_AS32.png //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15343 SUBJECT: GRB 131011A: Swift/UVOT Upper Limits DATE: 13/10/15 21:11:12 GMT FROM: Mike Siegel at PSU/Swift MOC L. M. Z. Hagen (PSU) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began observations of the field of GRB 131011A starting 83.9 ks after the Fermi trigger 403206457 (Kasliwal et al., GCN 15324). No optical afterglow consistent with the PTF position is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag w2 83920 97601 4896 >22.10 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15395 SUBJECT: GRB 131011A: ATCA 34GHz upper limit DATE: 13/10/29 02:23:40 GMT FROM: Paul Hancock at U of Sydney P. Hancock (Curtin University/CAASTRO), T. Murphy, B. Gaensler, M. Bell, D. Burlon (University of Sydney/CAASTRO), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI) We observed GRB131011A (GCN 15324) with the Australia Telescope Compact Array at 34GHz for 55 minutes centered on 11:20UT Oct-17-2013 in poor weather. We detect no radio source at the optical location of the GRB and place a 3sigma upper limit of 120uJy on the flux of an afterglow. These observations were obtained as part of ATCA project C2689. We thank the observatory staff for their support and scheduling the observations. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.