//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20423 SUBJECT: GRB 170111A: Swift detection of a burst DATE: 17/01/11 00:53:54 GMT FROM: David Palmer at LANL A. P. Beardmore (U Leicester), D. N. Burrows (PSU), C. Gronwall (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 00:33:28 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170111A (trigger=731887). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 20.717, -32.540 which is RA(J2000) = 01h 22m 52s Dec(J2000) = -32d 32' 23" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak structure with a duration of about 40 sec. The peak count rate was ~700 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 00:35:14.8 UT, 106.7 seconds after the BAT trigger. Using promptly downlinked data we find a variable, uncatalogued X-ray source with an enhanced position: RA, Dec 20.6981, -32.5653 which is equivalent to: RA(J2000) = 01h 22m 47.56s Dec(J2000) = -32d 33' 55.1" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 107 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 (3.10 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 4.1 (+2.60/-2.25) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 112 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 approximately 70% 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 0.03. Burst Advocate for this burst is A. P. Beardmore (apb AT star.le.ac.uk). 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: 20424 SUBJECT: GRB 170111A: Enhanced Swift-XRT position DATE: 17/01/11 04:24:27 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 564 s of XRT Photon Counting mode data and 1 UVOT images for GRB 170111A, 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 = 20.69735, -32.56485 which is equivalent to: RA (J2000): 01h 22m 47.36s Dec (J2000): -32d 33' 53.5" 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: 20427 SUBJECT: GRB 170111A: MASTER-OAFA (Argentina) prompt OT observations DATE: 17/01/11 14:51:27 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H. Levato, C. Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in OAFA (Argentina) was pointed to the GRB170111.02 17 sec after notice time and 63 sec after trigger time at 2017-01-11 00:34:31 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=20.7167 dec=-32.54 r=0.05). The 5-sigma upper limit has been about 17.5 mag The observations made on zenit distance = 25 degrees, galaxy latitude b = -81 degree. The moon (97 % bright part) is 26 degrees above the horizon. The distance between moon and object is 84 Observations started at twilight. The sun altitude is -9.8 degree. The object can be observed till 2017-01-11 06:13:03. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20431 SUBJECT: GRB 170111A: Swift-XRT refined Analysis DATE: 17/01/11 17:52:10 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester) and report on behalf of the Swift-XRT team: report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 170111A, from 96 s to 42.0 ks after the BAT trigger. The data comprise 17 s in Windowed Timing (WT) mode (the first 4 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=0.72 (+/-0.18). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.68 (+0.17, -0.16). The best-fitting absorption column is 3.6 (+0.9, -0.8) x 10^21 cm^-2, in excess of the Galactic value of 3.1 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.6 x 10^-11 (6.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.6 (+0.9, -0.8) x 10^21 cm^-2 Galactic foreground: 3.1 x 10^20 cm^-2 Excess significance: 6.6 sigma Photon index: 1.68 (+0.17, -0.16) If the light curve continues to decay with a power-law decay index of 0.72, the count rate at T+24 hours will be 0.020 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.5 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00731887. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20432 SUBJECT: GRB 170111A: SMARTS optical/IR observations DATE: 17/01/11 20:41:35 GMT FROM: Bethany Cobb at GWU B. E. Cobb (GWU) reports: Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 170111A (GCN 20423, Beardmore et al.) with a mid-exposure time of about 1 hour post-burst (2017-01-11 01:36 UT). Total summed exposure times amounted to 36 minutes in I and 30 minutes in J. No source is detected at the position of the X-ray afterglow (GCN 20424, Evans et al.) in either I or J, to an approximate 3-sigma limiting magnitude of I > 21.9 (calibrated using USNO-B1.0 stars). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20433 SUBJECT: GRB 170111A: Swift-BAT refined analysis DATE: 17/01/11 21:41:56 GMT FROM: Hans Krimm at NSF/NASA-GSFC H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), J. R. Cummings (CPI), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+739 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170111A (trigger #731887) (Beardmore, et al., GCN Circ. 20423). The BAT ground-calculated position is RA, Dec = 20.688, -32.541 deg which is RA(J2000) = 01h 22m 45.2s Dec(J2000) = -32d 32' 28.4" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%. The mask-weighted light curve shows a single, triangular shaped peak beginning at T-20 sec, peaking at T+0 sec and ending at about T+10 sec. T90 (15-350 keV) is 29.9 +- 9.4 sec (estimated error including systematics). The time-averaged spectrum from T-13.59 to T+25.32 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.64 +- 0.21. The fluence in the 15-150 keV band is 8.1 +- 1.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+2.09 sec in the 15-150 keV band is 0.9 +- 0.2 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/731887/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20435 SUBJECT: GRB170111A: REM optical/NIR observations DATE: 17/01/11 23:19:54 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, D. Fugazza, S. Covino, A. Melandri (INAF/OAB) report on behalf of the REM team: We observed the field of GRB 170111A (Beardmore et al., GCN 20423) with the 60-cm robotic telescope REM located at the La Silla Observatory (Chile). The observations started at 00:34:41 UT, 73 seconds after the burst, and were carried out simultaneously in the g, r, i, z and H bands. A preliminary photometry indicates that no source is detected at the X-ray afterglow position (Evans et al. GCN 20424) down to the following 3sigma limiting magnitudes: r > 16.3 at T-T0 = 78s H > 15.9 at T-T0 = 86s r > 18.9 at T-T0 = 706s H > 17.7 at T-T0 = 785s Magnitudes are in the AB system and have been calibrated with respect to the 2MASS (H-band) and APASS (r-band) catalogues. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20441 SUBJECT: GRB 170111A: Swift/UVOT Upper Limits DATE: 17/01/12 14:21:19 GMT FROM: Mike Siegel at PSU/Swift MOC M.H. Siegel (PSU) and A. P. Beardmore (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170111A 111 s after the BAT trigger (Beardmore et al., GCN Circ. 20423). No optical afterglow consistent with the XRT position (Evans et al., GCN Circ. 20424) 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 first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 111 261 147 >20.6 white 111 570 167 >20.7 v 601 621 19 >18.0 b 525 545 19 >19.6 u 676 696 19 >19.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).