//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19624 SUBJECT: GRB 160630A: Swift detection of a burst DATE: 16/06/30 04:19:45 GMT FROM: Hans Krimm at NASA-GSFC H. A. Krimm (CRESST/GSFC/USRA), P. D'Avanzo (INAF-OAB), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 04:04:09 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160630A (trigger=702252). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 198.239, -56.069 which is RA(J2000) = 13h 12m 57s Dec(J2000) = -56d 04' 06" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 160 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 04:05:33.0 UT, 83.1 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 198.2584, -56.0420 which is equivalent to: RA(J2000) = 13h 13m 02.03s Dec(J2000) = -56d 02' 31.3" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 104 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 consistent with the Galactic value of 3.89 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 87 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 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 0.48. Burst Advocate for this burst is H. A. Krimm (hans.krimm AT 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: 19625 SUBJECT: GRB 160630A: GROND Afterglow Detection DATE: 16/06/30 05:36:05 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann (TLS Tautenburg), T. Kruehler (MPE Garching), S. Schmidl (TLS Tautenburg), J. Bolmer, and J. Greiner (both MPE Garching) report on behalf of the GROND team. We observed the field of GRB 160630A (Swift trigger 702252; Krimm et al., GCN #19624) 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 ESO La Silla Observatory (Chile). Observations started at 04:10:58 UT, 6.8 minutes after the GRB trigger. They were performed at an average seeing of 2".1 and at an average airmass of 1.8. In an image with exposure time 66 s in g'r'i'z' taken at a mid-time of 7.3 min after the trigger, we detect a source at the edge of the 1".8 XRT error circle at position: RA (J2000) = 13:13:02.04 Dec. (J2000) = -56:02:29.8 (with an error of 0".3) with (AB magnitudes): g' > 21.0 mag, r' = 20.4 +/- 0.1 mag, i' = 19.5 +/- 0.1 mag, z' = 18.7 +/- 0.1 mag. The source faded by about 1.5 magnitudes within the next quarter hour. We therefore propose this source to be the afterglow of GRB 160630A. Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction E_(B-V) = 0.43 mag in the direction of the burst (Schlafly & Finkbeiner, 2011). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19626 SUBJECT: GRB 160630A: Enhanced Swift-XRT position DATE: 16/06/30 09:13:00 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 2865 s of XRT Photon Counting mode data and 6 UVOT images for GRB 160630A, 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 = 198.25909, -56.04183 which is equivalent to: RA (J2000): 13h 13m 2.18s Dec (J2000): -56d 02' 30.6" 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) 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: 19627 SUBJECT: GRB 160630A: REM NIR observations DATE: 16/06/30 09:46:38 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri, D. Fugazza, P. D'Avanzo, S. Covino (INAF/OAB) report on behalf of the REM team: We observed the field of GRB 160630A (Krimm et al., GCN 19624) with the 60-cm robotic telescope REM located at the La Silla Observatory (Chile). The observations started at 04:05:13 UT, ~65 seconds after the burst, and were carried out simultaneously in the g, r, i, z and H bands. A preliminary photometry indicates that the optical afterglow (Kann et al., GCN 16625) is detected with a magnitude H = 14.9 +/- 0.2, about 100 sec after the burst. Further analysis is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19630 SUBJECT: GRB 160630A: Swift-XRT refined Analysis DATE: 16/06/30 14:30:12 GMT FROM: Phil Evans at U of Leicester V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A. Maselli (INAF-IASFPA) and H.A. Krimm report on behalf of the Swift-XRT team: We have analysed 8.2 ks of XRT data for GRB 160630A (Krimm et al. GCN Circ. 19624), from 69 s to 24.5 ks after the BAT trigger. The data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 19626). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=3.3 (+4.7, -1.1). At T+110 s the decay flattens to an alpha of 0.20 (+/-0.14) before breaking again at T+2108 s to a final decay with index alpha=1.31 (+0.12, -0.11). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.74 (+0.13, -0.12). The best-fitting absorption column is 4.5 (+0.8, -0.6) x 10^21 cm^-2, consistent with the Galactic value of 3.9 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 4.6 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.5 (+0.8, -0.6) x 10^21 cm^-2 Galactic foreground: 3.9 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.74 (+0.13, -0.12) If the light curve continues to decay with a power-law decay index of 1.31, the count rate at T+24 hours will be 8.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.0 x 10^-13 (5.6 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/00702252. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19631 SUBJECT: GRB 160630A: Swift/UVOT Upper Limits DATE: 16/06/30 15:22:22 GMT FROM: Mike Siegel at PSU/Swift MOC S. J. LaPorte (PSU) and H. A. Krimm (CRESST/GSFC/USRA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160630A 87 s after the BAT trigger (Krimm et al., GCN Circ. 19624). No optical afterglow consistent with the enhanced XRT position (Goad et al., GCN Circ 19626) or the optical/IR position (Kann et al. GCN Circ. 19625) 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 87 237 147 >20.6 u_FC 300 550 246 >19.9 white 87 6366 530 >21.7 v 630 6777 439 >20.2 b 555 6161 236 >20.5 u 300 5956 462 >20.6 w1 680 7042 290 >19.7 m2 655 6982 432 >20.9 w2 606 6572 255 >19.7 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.48 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19633 SUBJECT: GRB 160630A: TAROT La Silla observatory optical observations DATE: 16/06/30 17:51:08 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report: We imaged the field of GRB 160630A detected by SWIFT (trigger 702252) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile. The observations started 33s after the GRB trigger (15s after the notice). The elevation of the field decreased from 34 degrees above horizon and weather conditions were good. 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 any OT with a limiting magnitude of: t0+33s to t0+93s : Rlim = 16.4 The second image is 30.0s exposure in tracking mode: t0+107s to t0+137s : Rlim = 17.5 We co-added a series of exposures: t0+107s to t0+302s : Rlim = 18.0 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19634 SUBJECT: GRB 160630A: Zadko observatory - Gingin optical observations DATE: 16/06/30 18:13:40 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.), Coward, D. McPherson, D. Williams A., Martin R., Moore J., Dodson R. (UWA) report: We imaged the field of GRB 160630A detected by SWIFT (trigger 702252) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 6.4h after the GRB trigger. The elevation of the field increased from 64 degrees above horizon and weather conditions were good. We co-added a series of exposures: t0+6.4h to t0+8.0h : Rlim = 21.0 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19636 SUBJECT: GRB 160630A: Skynet PROMPT-CTIO observations of the optical afterglow DATE: 16/06/30 18:42:41 GMT FROM: Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet A. Trotter, D. Reichart, J. Haislip, J. Moore, N. Frank, M. Maples, D. Dutton, R. Gao, R. Joyner, J. Martin, M. Paggen, J. A. Crain, K. Ivarsen, A. LaCluyze, and M. Nysewander report: Skynet observed the Swift BAT/XRT localization of GRB 160630A (Krimm et al., GCN 19624, Swift trigger=702252) with with two 16" telescopes (P5, P6), and two 24" telescopes (P1, P8) of the PROMPT array at CTIO, Chile. Starting at 2016-06-30 04:05 UT and continuing until 07:02 UT (t=60s-3h post-trigger), Skynet took a total of 452 2.5-160s exposures in the I band (P1, P5), V band (P6) and B band (P8). We detect a fading optical afterglow in stacked I-band images at the OT position reported by Kann et al. (GCN 19625) and Melandri et al. (GCN 19627), with I~17.4 at t=5m and I~18.6 at t=23m. A preliminary light curve is at: http://www.skynet.unc.edu/grb/grb160630a.png Preliminary magnitudes are in the Vega System, calibrated to 9 APASS DR9 stars in the field. Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.43 (Schlafly & Finkbeiner 2011). No further Skynet observations are scheduled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19639 SUBJECT: GRB 160630A: Swift-BAT refined analysis DATE: 16/07/01 12:43:23 GMT FROM: Amy Lien at GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), 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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160630A (trigger #702252) (Krimm, et al., GCN Circ. 19624). The BAT ground-calculated position is RA, Dec = 198.238, -56.029 deg which is RA(J2000) = 13h 12m 57.0s Dec(J2000) = -56d 01' 44.3" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 51%. The mask-weighted light curve shows a single-peaked structure that starts at ~T-1 s, peaks at ~T0, and ends at ~T+35 s. T90 (15-350 keV) is 29.50 +- 5.51 sec (estimated error including systematics). The time-averaged spectrum from T-1.00 to T+34.89 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.32 +- 0.14. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.42 sec in the 15-150 keV band is 1.2 +- 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/702252/BA/