//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18599 SUBJECT: GRB 151114A: Swift detection of a burst with an optical counterpart DATE: 15/11/14 10:12:35 GMT FROM: Scott Barthelmy at NASA/GSFC M. H. Siegel (PSU), S. D. Barthelmy (GSFC), N. P. M. Kuin (UCL-MSSL), L. M. McCauley (PSU) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 09:59:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151114A (trigger=663490). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 120.937, -61.042, which is RA(J2000) = 08h 03m 45s Dec(J2000) = -61d 02' 31" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a couple peaks with a duration of about 20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 10:01:03.9 UT, 89.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 120.94436, -61.02743 which is equivalent to: RA(J2000) = 08h 03m 46.65s Dec(J2000) = -61d 01' 38.7" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 53 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. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.01 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 94 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 08:03:46.33 = 120.94305 DEC(J2000) = -61:01:40.0 = -61.02779 with a 90%-confidence error radius of about 0.63 arc sec. This position is 1.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.84 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.17. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.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: 18600 SUBJECT: GRB 151114A: Enhanced Swift-XRT position DATE: 15/11/14 13:56:04 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 1128 s of XRT Photon Counting mode data and 2 UVOT images for GRB 151114A, 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 = 120.94305, -61.02792 which is equivalent to: RA (J2000): 08h 03m 46.33s Dec (J2000): -61d 01' 40.5" 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: 18601 SUBJECT: GRB 151114A: LCOGT-FTS afterglow observations DATE: 15/11/14 18:33:47 GMT FROM: Simone Dichiara at Ferrara U/Italy S. Dichiara (U. Ferrara, ICRANet), C. Guidorzi (U. Ferrara), A. Melandri (INAF-OAB), C.G. Mundell (U. Bath), S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana) on behalf of a large collaboration report: The 2-m Faulkes Telescope South began observing Swift GRB 151114A (Siegel et al. GCN 18599) on November 14, 12:18:07 UT (~2.3 hours after the BAT trigger) with SDSS R and I filters. we identify the optical afterglow (Siegel et al. GCN 18599) in the R filter with R = 20.6 +/- 0.2 mag at a mid time of 2.64 hours post burst (total exposure 600 s). The counterpart is detected also visible in the I-band image. Data reduction and calibration continue. The magnitude is calibrated against nearby USNOB-1 stars (R2). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18602 SUBJECT: GRB 151114A: Swift/UVOT Detection DATE: 15/11/14 19:34:41 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 151114A 95 s after the BAT trigger (Siegel et al., GCN Circ. 18599). A source consistent with the XRT position (Siegel et al. GCN Circ. 18599) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:03:46.33 = 120.94306 (deg.) Dec (J2000) = -61:01:40.0 = -61.02779 (deg.) with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence). 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 95 244 147 18.61 +/- 0.06 v 638 1233 72 >18.4 b 563 1164 58 19.45 +/- 0.26 u 307 557 246 18.46 +/- 0.09 w1 688 1115 39 >18.3 m2 662 1090 58 >19.2 w2 613 1215 78 >19.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.17 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18604 SUBJECT: GRB 151114A: Swift-BAT refined analysis DATE: 15/11/14 20:49:26 GMT FROM: Scott Barthelmy at NASA/GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. H. Siegel (PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlinks, we report further analysis of BAT GRB 151114A (trigger #663490) (Siegel, et al., GCN Circ. 18599). The BAT ground-calculated position is RA, Dec = 120.947, -61.033 deg, which is RA(J2000) = 08h 03m 47.4s Dec(J2000) = -61d 01' 58.3" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 30%. The mask-weighted light curve shows a single peak starting at ~T-4 sec, peaking at ~T0 sec, and ending at ~T+1 sec. T90 (15-350 keV) is 4.86 +- 0.98 sec (estimated error including systematics). The time-averaged spectrum from T-4.26 to T+1.25 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.14 +- 0.25. The fluence in the 15-150 keV band is 3.7 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band is 2.9 +- 0.4 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/663490/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18606 SUBJECT: GRB 151114A: Swift-XRT refined Analysis DATE: 15/11/15 10:12:04 GMT FROM: Phil Evans at U of Leicester L.M. McCauley (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and M.H. Siegel report on behalf of the Swift-XRT team: We have analysed 6.1 ks of XRT data for GRB 151114A (Siegel et al. GCN Circ. 18599), from 97 s to 48.6 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 18600). The light curve can be modelled with a power-law decay with a decay index of alpha=0.73 (+0.05, -0.04). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.00 (+0.16, -0.12). The best-fitting absorption column is consistent with the Galactic value of 2.0 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.0 (+/-0.3) x 10^21 cm^-2 Galactic foreground: 2.0 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 2.00 (+0.16, -0.12) If the light curve continues to decay with a power-law decay index of 0.73, the count rate at T+24 hours will be 8.2 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x 10^-13 (3.8 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/00663490. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18607 SUBJECT: GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate DATE: 15/11/15 16:10:09 GMT FROM: Jan Bolmer at MPE/Garching J. Bolmer, F. Knust and J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 151114A (Swift trigger 663490; Siegel et al., GCN #18599) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at the ESO La Silla Observatory (Chile). Observations started at 04:59 UT on 2015-11-15, 19.5hrs after the GRB trigger. They were performed at an average seeing of 1.8" and at an average airmass of 1.5. We found a single point source within the 1.8" Swift-XRT and 0.45" Swift-UVOT error circles reported by Beardmore et al. (GCN #18600) and Kuin et al. (GCN #18602) at RA, Dec = 120.94299, -61.02778 RA (J2000.0) = 08h 03m 46.32s DEC (J2000.0) = -61d 01' 40.0" with an uncertainty of 0.3" in each coordinate. Based on 25.2 min of total exposures in g'r'i'z' and 25.5 min in JHK, we estimate preliminary magnitudes (all in AB system) of g' = 23.7 +/- 0.3 mag, r' = 23.2 +/- 0.2 mag, i' = 23.1 +/- 0.3 mag, z' = 23.3 +/- 0.4 mag, J > 21.4 mag, H > 20.9 mag, and K > 19.5 mag. Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.17 mag in the direction of the burst (Schlegel et al. 1998).