//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7733 SUBJECT: GRB 080516: Swift detection of a burst DATE: 08/05/16 00:47:29 GMT FROM: David Burrows at PSU/Swift S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), E. A. Hoversten (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester) and E. Troja (U Leicester/INAF-IASFPA) report on behalf of the Swift Team: At 00:17:07 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080516 (trigger=311762). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 120.629, -26.176 which is RA(J2000) = 08h 02m 31s Dec(J2000) = -26d 10' 33" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 20 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 00:18:29.9 UT, 82.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 120.64234, -26.15900 which is equivalent to: RA(J2000) = 08h 02m 34.16s Dec(J2000) = -26d 09' 32.4" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This is 75 arcsec from the BAT position, within the BAT error circle. UVOT took a finding chart exposure of nominal 400 seconds with the V filter starting 81 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. This is a particularly crowded field with many stars. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The limiting magnitude is about 17.7. No correction has been made for the large, but uncertain extinction expected. Burst Advocate for this burst is S. T. Holland (sholland AT milkyway.gsfc.nasa.gov). 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: 7735 SUBJECT: GRB 080516: Enhanced Swift-XRT position DATE: 08/05/16 07:56:46 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 799 s of overlapping XRT Photon Counting mode and UVOT data for GRB 080516, 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 = 120.64196, -26.15962 which is equivalent to: RA (J2000): 08 02 34.07 Dec (J2000): -26 09 34.6 with an uncertainty of 1.7 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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7736 SUBJECT: GRB 080516, Swift-BAT refined analysis DATE: 08/05/16 10:40:50 GMT FROM: Scott Barthelmy at NASA/GSFC H. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), S. T. Holland (CRESST/USRA/GSFC), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 080516 (trigger #311762) (Holland, et al., GCN Circ. 7733). The BAT ground-calculated position is RA, Dec = 120.661, -26.146 deg, which is RA(J2000) = 08h 02m 38.7s Dec(J2000) = -26d 08' 46.9" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 38%. The mask-weighted light curve shows two well separated peaks. The first peak starts at T-0.1 sec, peaks at T+0.3 sec, and ends at T+1.0 sec. The second peak starts at T+3.5 sec, peaks at T+5.5 sec, and ends at T+7.5 sec. T90 (15-350 keV) is 5.8 +- 0.3 sec (estimated error including systematics). The time-averaged spectrum from T+0.1 to T+6.1 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.82 +- 0.27. The fluence in the 15-150 keV band is 2.6 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.05 sec in the 15-150 keV band is 1.8 +- 0.3 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/311762/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7737 SUBJECT: GRB 080516: Swift-XRT Team refined analysis DATE: 08/05/16 11:08:12 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester) and S.T. Holland (CRESST/USRA/GSFC) report on behalf of the Swift-XRT team: We have analysed the first five orbits of data obtained for GRB 080516 (Holland et al., GCN Circ. 7733), covering 11.5 ks of Photon Counting (PC) mode data. The UVOT-enhanced XRT position was given by Beardmore et al. in GCN Circ. 7735. The light-curve begins relatively flat, with a decay of alpha ~ 0.36 +/- 0.17, until around 4800 seconds after the trigger, at which point the slope steepens to 1.04 +0.20/-0.18. The first five orbits of PC data can be modelled with an absorbed power-law, with Gamma = 2.7 +/- 0.4 and total NH = (1.3 +/- 0.3)x10^22 cm^-2, considerably in excess of the Galactic value of 3.22x10^21 cm^-2. Using the relation in Grupe et al. (2007, ApJ, 133, 2216), this implies an estimated upper limit on the redshift of the burst of z<1.0. There is no evidence for spectral evolution across the temporal break. The observed (unabsorbed) flux over this time interval (90-2.5x10^4 s after the trigger) is 2.38x10^-12 (1.06x10^-11) erg cm^-2 s^-1. The counts to observed flux conversion is 5.8x10^-11 erg cm^-2 count^-1. If the light-curve continues to decay at alpha ~ 1.04, the count rate at 24 hours is predicted to be 3.7x10^-3 count s^-1, corresponding to an observed flux of 2.1x10^-13 erg cm^-2 s^-1. This is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7738 SUBJECT: GRB 080516, SMARTS optical/IR observations DATE: 08/05/16 17:00:13 GMT FROM: Bethany Cobb at Yale U B. E. Cobb (Yale), part of the larger SMARTS consortium, reports: Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 080516 (GCN 7733, Holland et al.) with a mid-exposure time of 2008-05-16 01:27 UT (~1.2 hrs post-burst). Total summed exposure times amounted to 36 minutes in I and 30 minutes in J. No afterglow is detected at the enhanced Swift-XRT position (GCN 7735, Beardmore et al.). The 3-sigma limiting magnitudes of our images are I>21.6 and J>19.5. We caution, however, that the afterglow position falls very near a I~10 mag star. Optical photometry is calibrated against Landolt standard stars and IR photometry is calibrated against 2MASS stars in the field. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7740 SUBJECT: GRB 080516, GROND observations DATE: 08/05/17 00:15:11 GMT FROM: Sylvio Klose at TLS Tautenburg R. Filgas (Tautenburg), A. Kupcu-Yoldas, J. Greiner (MPE Garching), A. Rossi, S. Klose (Tautenburg), A. Yoldas, T. Kruehler (MPE), and G. Szokoly (Eoetvoes Univ. Budapest and MPE) report on behalf of the GROND team: We observed the field of GRB 080516 (Holland et al. 2008, GCN 7733) simultaneously in g'r'i'z'JHK using the multi-channel imager GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPI/ESO telescope on La Silla (Chile). Observations started at 00:25 UT, 8 min after the burst. At the border of the revised XRT error circle (Beardmore et al., GCN 7735) we detect in all bands a faint source at RA, DEC (J2000) = 08:02:33.96, -26:09:33.6 (+/- 0.5") with r'= 23.92 +/- 0.2 at ~1 hr after the burst, calibrated against NOMAD field stars. This source is very close to a brighter foreground point source and close to a very bright star (Cobb et al., GCN 7738). Note that due to visibility constraints observations could only be performed for two hours. Problems with the photometry did not allow us to report these results earlier. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7747 SUBJECT: GRB 080516, GROND further analysis DATE: 08/05/18 18:03:48 GMT FROM: Sylvio Klose at TLS Tautenburg R. Filgas (Tautenburg), A. Kupcu-Yoldas, J. Greiner (MPE Garching), A. Rossi, S. Klose (Tautenburg), A. Yoldas, T. Kruehler (MPE), and G. Szokoly (Eoetvoes Univ. Budapest and MPE) report on behalf of the GROND team: Our previous report (Filgas et al., GCN 7740) contains a typo in the reported r'-band magnitude. It must be read r'=21.92 +/- 0.2 instead of 23.92 +/- 0.2. We apologize for this mistake. After a re-analysis of the data, to correct for the effects of the nearby star, we conclude that the object is not detected in the g' band to an upper limit of g' > 23.0. From the SED of the afterglow, we estimate a photometric redshift of z = 3.2 +/- 0.3 using HyperZ (Bolzonella et al. 2000). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7798 SUBJECT: GRB 080516: TAROT La Silla observatory optical observations DATE: 08/06/03 23:32:33 GMT FROM: Alain Klotz at CESR-CNRS Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report: We imaged the field of GRB 080516 detected by SWIFT (trigger 311762) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile. The observations started 64.6s after the GRB trigger (49.9s after the notice). The elevation of the field decreased from 48 degrees above horizon and weather conditions were excellents. The date of trigger : t0 = 2008-05-16T00:17:07.296 The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect the OT noticed by Filgas et al. (GCNC 7740) with a limiting magnitude of: t0+64.6s to t0+124.6s : R > 13.5 (the poor detectivity is due to the 10 magnitude close star). The second image is 30.0s exposure in tracking mode: t0+131.0s to t0+161.0s : R > 15 (we substracted an image taken at t0+20 min to minimize the effect of the 10 magnitude close star). Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=244.1279 lat= +2.4429 and the galactic extinction in R band is 1.1 magnitude estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8485 SUBJECT: Radio observation of GRB 080516 with ATCA DATE: 08/11/06 08:11:48 GMT FROM: Aquib Moin at CIRA/ATNF Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope National Facility), Steven Tingay (Curtin Institute of Radio Astronomy), Chris Phillips (Australia Telescope National Facility), Gregory Taylor (University of New Mexico), Mark Wieringa (Australia Telescope National Facility) and Ralph Martin (Perth Observatory) report: We observed the BAT refined position of the GRB 080516 (GCN 7736) at 4.8 GHz with the Australia Telescope Compact Array (ATCA) on June 01, 2008 between 03:54:25 UT and 07:45:35 UT. We did not detect a radio source at the BAT position of the GRB 080516 (GCN 7736). The radio flux density at the GRB position is -0.128 +/- 0.224 mJy at 4.8 GHz (1-sigma). The Australia Telescope Compact Array (/ Parkes telescope / Mopra telescope / Long Baseline Array) is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. See field image at: http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080516_field_image