//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13654 SUBJECT: GRB 120816A: Swift detection of a burst DATE: 12/08/16 19:32:32 GMT FROM: Scott Barthelmy at NASA/GSFC K. L. Page (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), S. T. Holland (STScI), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team: At 19:18:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120816A (trigger=531223). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 282.126, -6.979, which is RA(J2000) = 18h 48m 30s Dec(J2000) = -06d 58' 43" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak with a duration of about 5 sec. The peak count rate was ~800 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 19:20:47.3 UT, 132.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 282.14430, -6.93753 which is equivalent to: RA(J2000) = 18h 48m 34.63s Dec(J2000) = -06d 56' 15.1" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 162 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 (3.73 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 4.4 (+3.28/-2.78) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 134 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 none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 0.00% of the XRT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the large, but uncertain extinction expected. Burst Advocate for this burst is K. L. Page (kpa 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: 13655 SUBJECT: GRB 120816A: ROTSE-III Optical Limits DATE: 12/08/16 20:18:36 GMT FROM: Weikang Zheng at U.of Michigan W. Zheng (U Mich), W. Rujopakarn (Steward), T. Guver (Sabanci University), report on behalf of the ROTSE collaboration: ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe, Turkey, automatically responded to GRB 120816A (Swift trigger 531223; Page et al., GCN 13654). An automated response took the first image at 19:23:18.6 UT, 285 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 50 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going. Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle or the XRT error circle; however, we are limited as the field is severely crowded. Individual images have limiting magnitudes ranging from 13.9-15.1; we set the following specific limits. start UT end UT t_exp(s) mlim Coadd? ---------------------------------------------------- 19:23:18.6 19:23:23.6 5 13.9 N 19:23:45.6 19:23:50.6 5 14.2 N 19:24:13.1 19:24:18.1 5 14.3 N 19:25:34.5 19:25:54.5 20 14.8 N 19:35:05.4 19:40:22.7 600 15.1 Y //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13656 SUBJECT: GRB 120816A: TAROT Calern observatory optical observations DATE: 12/08/16 21:16:46 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 120816A detected by SWIFT (trigger 531223) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 526s after the GRB trigger (delay due to the beginning of the night). The elevation of the field increased from 36 degrees above horizon and weather conditions were good. We co-added a series of exposures but we do not detect any OT at the XRT position (Page et al. GCNC 13654): From t0+526s to t0+942s, R > 16.5 Galactic coordinates are lon= 26.384d lat= -2.527d and the galactic extinction in R band is about 3 magnitudes (estimated from D. Schlegel et al. 1998ApJ...500..525S). Although the field is very dense, there are no star brighter than 18th mag in the XRT error box. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13657 SUBJECT: GRB120816A: OPTIMA discovery of optical counterpart DATE: 12/08/16 21:39:46 GMT FROM: Arne Rau at MPE Arne Rau and Gottfried Kanbach (both MPE Garching) report on behalf of the OPTIMA-Burst Team: "We observed the location of GRB 120816A (Page et al. GCN #13654) with OPTIMA-Burst (Kanbach et al. 2008, Astrophys. and Sp. Sci. Lib. Vol. 351, 153) currently mounted at the 1.3m telescope at Skinakas Observatory, University of Crete. Observations started at 19:22:44 UT (249 sec after the burst) with unfiltered 20s exposures using the field-viewing CCD camera. Within the updated XRT error circle we find a fading source located at: RA(J2000) = 18:48:34.4 Dec(J2000) = -06:56:16 with an approximate uncertainty of 1" in both coordinates. We measure the following magnitudes: T0+ white -------------- 249s ~17.8 4844s >19.1 calibrated against the R=15.2mag reference star USNO-B1.0 0830-0537586." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13658 SUBJECT: GRB 120816A: BOOTES-2 observations DATE: 12/08/16 23:35:34 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia M. Jelínek, J. C. Tello, J. Gorosabel and A. J. Castro-Tirado (IAA-CSIC Granada), on behalf of a larger collaboration, report: "Following the detection of GRB 120816A (Page et al. GCNC 13654), the BOOTES-2/TELMA 0.6m telescope (+COLORES) in southern Spain started to observe the field about one hour after the GRB, as soon as the night started, obtaining a series of unfiltered images. In particular, a combination of 15x60s frames gathered around 20:24:35UT (i.e. T0+66min) provides a limit of R > 18 at the position of the reported optical counterpart (Rau and Kanbach GCNC 13657)." This message can be quoted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13659 SUBJECT: GRB 120816A: Swift-BAT refined analysis DATE: 12/08/17 02:28:16 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+192 sec from the recent telemetry downlink, we report further analysis of BAT GRB 120816A (trigger #531223) (Page, et al., GCN Circ. 13654). The BAT ground-calculated position is RA, Dec = 282.133, -6.981 deg, which is RA(J2000) = 18h 48m 32.0s Dec(J2000) = -06d 58' 51.6" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%. The mask-weighted light curve shows a single peak starting at ~T+0 sec, peaking at ~T+1 sec, and ending at ~T+8 sec. T90 (15-350 keV) is 7.6 +- 3.1 sec (estimated error including systematics). The time-averaged spectrum from T-1.97 to T+6.66 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.54 +- 0.40. The fluence in the 15-150 keV band is 4.3 +- 1.0 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.82 sec in the 15-150 keV band is 2.1 +- 0.5 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/531223/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13660 SUBJECT: GRB 120816A: Enhanced Swift-XRT position DATE: 12/08/17 05:34:39 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2433 s of XRT Photon Counting mode data and 4 UVOT images for GRB 120816A, 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 = 282.14298, -6.93791 which is equivalent to: RA (J2000): 18h 48m 34.31s Dec (J2000): -06d 56' 16.5" 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) 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: 13663 SUBJECT: GRB 120816A: Swift-XRT refined Analysis DATE: 12/08/17 09:04:33 GMT FROM: Kim Page at U.of Leicester K. L. Page (U Leicester) reports on behalf of the Swift-XRT team: We have analysed 5.6 ks of XRT data for GRB 120816A (Page et al. GCN Circ. 13654), from 136 s to 12.5 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 13660). The light curve can be modelled with a power-law decay with a decay index of alpha=0.94 (+0.08, -0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.10 (+0.26, -0.25). The best-fitting absorption column is 6.4 (+1.5, -1.4) x 10^21 cm^-2, in excess of the Galactic value of 3.7 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 4.8 x 10^-11 (9.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.4 (+1.5, -1.4) x 10^21 cm^-2 Galactic foreground: 3.7 x 10^21 cm^-2 Excess significance: 3.2 sigma Photon index: 2.10 (+0.26, -0.25) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00531223. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13665 SUBJECT: GRB 120816A: Bassano Bresciano Observatory optical observations DATE: 12/08/17 12:14:44 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla and R.Girelli A.Quadri report: We imaged the field of GRB 120816A detected by SWIFT(trigger 531223) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy. The observations started 26.7 min. after the GRB trigger,with our schmidt telescope D=320 mm F/D=3.1. Weather conditions were discrete. We co-added 4 series of 30 x 120s exposures. We did not appear any optical counterpart in the error box of the XRTcandidate (Page et al.GCNC 13654). Start End Vlim 27.6min 278min 17.7 Magnitudes were estimated with the USNO-B1 cat. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13668 SUBJECT: GRB 120816A: optical upper limit DATE: 12/08/17 16:17:06 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Ivanov, V. Ivanov, V. Lysenko (Kuban State University), A. Pozanenko (IKI) We observed the field of the Swift GRB 120816A (Page et al., GCN 13654) with 20-inch telescope of Kuban State University Astrophysical Observatory on August 16 starting on (UT) 19:34:49. We took several series of 40 s and 60 s exposures using R filter. In a stacked image we do not detect any new source in the enhanced XRT error circle (Osborne et al., GCN 13660), in particular we do not detect the OT candidate (Rau et al., GCN 13657). A preliminary photometry is based on the nearby USNO-B1.0 (R2) stars: Start, T0+ Filter, Exposure, OT, uplim (3 sigma) (UT) (mid, d) (s) 19:34:49 0.0115 R 40 n/d 16.0 19:36:01 0.0221 R 830 n/d 17.9 19:36:01 0.0539 R 3530 n/d 18.1 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13675 SUBJECT: IPN Triangulation of GRB 120816B (short/exceptionally intense) DATE: 12/08/18 14:32:17 GMT FROM: Dmitry Svinkin at Ioffe Institute S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, K. Hurley on behalf of the IPN, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, and 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, report: The short-duration, hard, exceptionally intense GRB 120816B has been observed by Konus-Wind, INTEGRAL (SPI-ACS), Suzaku (WAM), and Swift(BAT), at about 86299 s UT (23:58:19). The burst was outside the coded field of view of the BAT. We have triangulated the burst to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Corners: 341.155 (22h 44m 37s) +2.156 ( +2d 09' 22") 342.478 (22h 49m 55s) -0.731 ( +0d 43' 51") 334.205 (22h 16m 49s) -5.388 ( -5d 23' 15") 332.423 (22h 09m 42s) -2.756 ( -2d 45' 20") --------------------------------------------- The error box area is 10.030 sq. deg This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB120816_T86298/IPN/ The time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13676 SUBJECT: Konus-Wind observation of GRB 120816B DATE: 12/08/18 14:52:56 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The short-duration hard-spectrum exceptionally intense GRB 120816B (IPN localization: Golenetskii at al., GCN 13675) triggered Konus-Wind at T0=86298.852s UT (23:58:18.852) The light curve shows a single multi-peaked pulse. A total duration of the burst in is ~0.8 s (80-350 keV range) with a hint of a soft extended tail lasting till ~T0+50 s. The emission in the main phase of the burst is seen up to ~9 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120816_T86298/ As observed by Konus-Wind the burst had a fluence of 9.7(-0.5,+0.5)x10-5 erg/cm2, and a 16-ms peak flux, measured from T0, of 2.3(-0.2,+0.2)x10-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+0.768 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which alpha = -0.61 (-0.04, +0.04), and Ep = 2320(-130, +140) keV, chi2 = 100/89 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13678 SUBJECT: GRB 120816A: Swift/UVOT Detection of the Optical Afterglow DATE: 12/08/18 16:32:59 GMT FROM: Stefan Immler at NASA/GSFC S. Immler (NASA/CRESST/GSFC) and K. L. Page (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT observed the field of GRB 120815A starting 117 s after the BAT trigger (Page et al., 2012, GCNC 13654). We detect an uncatalogued source inside the enhanced XRT error circle (Osborne et al., 2012, GCNC 13660) with preliminary coordinates RA (J2000.0) = 18:48:34.5 = 282.14359 (deg) Dec (J2000.0) = -06:56:16.4 = -6.93788 (deg) and an estimated uncertainty of 0.6 arcsec (radius, 90% confidence, statistical + systematic). The UVOT detection is consistent with the optical afterglow reported by Rau et al. (2012, GCNC 13657). Source magnitudes and 3-sigma upper limits at this location are given below (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373). Filter TSTART TSTOP Exp Time Mag Err ----------------------------------------------------- white 134 284 147 18.5 0.2 white 573 6306 598 19.9 0.2 v 117 6716 500 >19.0 b 548 11345 1174 >19.6 u 293 7286 672 >21.1 uvw1 672 7126 490 >21.1 uvm2 647 6921 490 >19.5 uvw2 599 6511 490 >19.8 ----------------------------------------------------- The quoted magnitudes and upper limits have not been corrected for the Galactic extinction along the line of sight to this burst of E_{B-V} = 0.703 mag.