//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9793 SUBJECT: GRB 090814: Swift detection of a burst DATE: 09/08/14 01:13:22 GMT FROM: David Palmer at LANL T. N. Ukwatta (GSFC/GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (OSU/NASA/GSFC) and M. A. Stark (PSU) report on behalf of the Swift Team: At 00:52:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090814 (trigger=359951). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 239.611, +25.599 which is RA(J2000) = 15h 58m 27s Dec(J2000) = +25d 35' 57" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows multiple weak peaks with a total duration of about 30 seconds. The peak count rate was ~500 counts/sec (15-350 keV), at 10 sec before the trigger. The XRT began observing the field at 00:54:58.3 UT, 159.3 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 239.6095, 25.6310 which is equivalent to: RA(J2000) = 15h 58m 26.29s Dec(J2000) = +25d 37' 51.7" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 115 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 4.76e+20 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 1.65e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 169 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 100% of the XRT error circle. The 3-sigma UL at the XRT position is 19.2 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.08. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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: 9794 SUBJECT: GRB 090814: GROND Detection of an Optical Afterglow Candidate DATE: 09/08/14 02:59:30 GMT FROM: Felipe Olivares Estay at MPE GRB 090814: GROND Detection of an Optical Afterglow Candidate Adria Updike (Clemson University), Felipe Olivares, Paulo Afonso, Abdullah Yoldas, Jochen Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 090814 (Swift trigger 359951; Ukwatta et al., GCN #9793) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile). Observations started at 00:59 UT on Aug 14 2009, 7 minutes after the GRB trigger. They were performed at an average seeing of 1" and at an average airmass of 2.2. We found a single point source within the Swift-XRT error circle reported by Ukwatta et al. (GCN #9793) at RA (J2000.0) = 15 h 58 m 26.35 s DEC (J2000.0) = +25d 37' 52.4" with an uncertainty of 0.5". The candidate afterglow has the following preliminary AB magnitudes obtained from a first 140s g'r' exposure and 240s in the nIR: g' = 21.62 +/- 0.04 r' = 21.21 +/- 0.04 J > 21.1 H > 19.2 calibrated against SDSS and 2MASS catalogs. No extinction correction was applied. Ongoing data reduction suggests the source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9796 SUBJECT: GRB 090814: Enhanced Swift-XRT position DATE: 09/08/14 03:58:44 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 2113 s of XRT Photon Counting mode data and 1 UVOT images for GRB 090814, 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 = 239.61014, +25.63088 which is equivalent to: RA (J2000): 15h 58m 26.43s Dec (J2000): +25d 37' 51.2" 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, arXiv:0812.3662). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9797 SUBJECT: GRB090814A: VLT spectroscopy DATE: 09/08/14 05:07:03 GMT FROM: Antonio Deugarte at IAA-CSIC P. Jakobsson (Univ. Iceland), A. de Ugarte Postigo (INAF-OAB), J. Gorosabel (IAA-CSIC), N. Tanvir (Leicester), L. Christensen (ESO), J.P.U. Fynbo (DARK/NBI) report on behalf of a larger collaboration, We have observed the field of GRB 090814A (Ukwatta et al. GCN 9793) using FORS2 at the VLT (Paranal observatory) starting at 02:05 UT (70 minutes after the burst). We detect the object identified by Updike et al. (GCN 9794) with a magnitude of R~21.5. The spectrum shows continuum down to at least 3900 Angstroms. Non detection of Ly-alpha implies a limit of z < 2.2. We identify a weak absorption system at z=0.696 through the detection of MgII and CaII. This is therefore likely to be the redshift of the GRB but we note that it could also be produced by an intervening system and thus the strict redshift range for this GRB would be 0.696 < z < 2.2. We acknowledge the excelent support from Parnal observatory, in particular J. Smoker and L. Rivas. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9799 SUBJECT: GRB 090814A: Swift-BAT refined analysis DATE: 09/08/14 12:55:19 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090814A (trigger #359951) (Ukwatta, et al., GCN Circ. 9793). The BAT ground-calculated position is RA, Dec = 239.613, 25.586 deg which is RA(J2000) = 15h 58m 27.2s Dec(J2000) = +25d 35' 09.0" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 37%. The mask-weighted light curve shows a few semi-overlapping peaks starting at ~T-18 sec, peaking at ~T-13 sec, peaking at ~T+8 sec, and ending at ~T+115 sec. There is possible 10-sec precursor peak (3 sigma) at ~T-145 sec. T90 (15-350 keV) is 80 +- 8 sec (estimated error including systematics). The time-averaged spectrum from T-16.4 to T+73.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.81 +- 0.19. The fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-12.68 sec in the 15-150 keV band is 0.6 +- 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/359951/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9800 SUBJECT: GRB 090814A, RIMOTS optical upper limits DATE: 09/08/14 13:16:44 GMT FROM: Arata Daikyuji at Miyazaki U A.Daikyuji, K.Noda, H.hayasi, K.Kono, N.Ohmori, E.Sonoda, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB 090814A (Swift trigger 359951, GCN 9793, T. N. Ukwatta et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 00:59 UT, about 11 hr after the Swift trigger time. We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, There is no new source at the reported position. ((GCN9794(Adria Updike et al.)) the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 11:08:33 11:09:03 1 16.2 11:08:33 11:48:08 36 17.3 --------------------------------------------------------------- //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9801 SUBJECT: GRB 090814A: Swift-XRT Team Refined Analysis DATE: 09/08/14 13:33:54 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester) & T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift-XRT team: We have analysed the first four orbits of data collected for GRB 090814A, from 165 s to 25.7 ks after the BAT trigger. These data comprise 258 s in Windowed Timing (WT) mode and 7.8 ks in Photon Counting mode. The enhanced XRT position for this burst was given by Beardmore et al. in GCN Circ. 9796. The light curve can be modelled with a series of power-law decays, starting with alpha1 = 2.60 +/- 0.08 until ~T+830 s, at which point the decay flattens slightly to alpha2 = 1.91 +/- 0.20. The light curve flattens again at ~T+5.4 ks, to a slope of alpha3 = 0.51 +/- 0.48. With the limited data at this time, alpha3 has a relatively large uncertainty. The spectrum extracted from the WT data can be fitted with an absorbed power-law, with Gamma = 2.78 +0.12/-0.11, absorbed by the Galactic column of NH = 4.76 x 10^20 cm^-2 (Kalberla et al. 2005), together with an intrinsic column (assuming z = 0.696; Jakobsson et al., GCN Circ. 9797) of (2.0 +/- 0.4) x 10^21 cm^-2. Note, however, that this redshift determination is uncertain. The total (including Galactic) column at z = 0 would be (1.3 +/- 0.2) x 10^21 cm^-2. Alternatively, the spectrum is better fitted (at >3 sigma) by a broken power-law with Gamma1 = 0.47 +0.72/-1.59 below a break energy of 0.62 +0.09/-0.08 keV, followed by Gamma2 = 2.62 +/- 0.09; this fit only requires the Galactic column. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from the broken power-law fit is 2.5 x 10^-11 (3.0 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 0.51, the count rate at T+24 hours will be 0.0041 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x 10^-13 (1.2 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/00359951. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9802 SUBJECT: GRB 090814A: Swift/UVOT Observations DATE: 09/08/14 13:52:07 GMT FROM: Peter Curran at MSSL P.A. Curran (MSSL-UCL), T. N. Ukwatta (GSFC/GWU), report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 090814A 170s after the BAT trigger (Ukwatta et al., GCN 9793). The proposed optical counterpart (Updike et al. , GCN 9794) is marginally detected in the u and white UVOT exposures. No optical afterglow consistent with the enhanced XRT position (Beardmore et al., GCN 9796) is detected in the other UVOT exposures. Preliminary magnitudes and 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for for the first finding charts (FC) and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag u 328 577 246 > 20.16 (FC) wh 170 319 147 > 20.70 (FC) u 328 8144 834 21.05 +/- 0.35 b 584 8340 599 > 21.30 v 658 7528 607 > 20.18 w1 708 7939 529 > 20.66 m2 683 7733 529 > 20.5 w2 708 7939 607 > 20.81 wh 170 7117 699 21.54 +/- 0.27 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.078 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9809 SUBJECT: GRB090814A: NOT optical follow-ups DATE: 09/08/14 23:02:39 GMT FROM: Dong Xu at DARK,NBI D. Xu, J.P.U. Fynbo (DARK/NBI), P. Jakobsson (Univ. Iceland), Tiina Liimets (NOT) report on behalf of a larger collaboration: We observed the field of GRB 090814A (Ukwatta et al. GCN 9793; Updike et al., GCN 9794) with the Nordic Optical Telescope equipped with ALFOSC. We obtained 3x600 s R-band frames staring on August 14th, 21:15:11 UT, 20.38 hr after the burst. The optical afterglow is clearly detected in each frame. The magnitude is R~22.4 calibrated against the reference star, #1156-0231252 with R2=19.25, of the USNO B1 catalog. Compared with the previous measurement of R~21.5 around 70 mins after the burst (Jakobsson et al., GCN 9797), the afterglow is decaying quite shallowly, with a power-law slope of ~0.3, being consistent with the X-ray decaying law during the same period (Page & Ukwatta, GCN 9801). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9818 SUBJECT: GRB 090814A: optical observations DATE: 09/08/17 11:07:26 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO) and A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 090814A (Ukwatta et al. GCN 9793; Updike et al., GCN 9794) with Shajn telescope of CrAO on Aug. 14 between (UT) 19:02:44 - 19:56:58 under modarate seeing of about 1.9 arcsec. We detect afterglow in a stacked image. The coordinates of the afterglow are (J2000) 15 58 26.36 +25 37 52.32 in a full agreement with reported earlier (A. Updike et al., GCN 9794). The photometry against nearby USNO-B1.0 star 15 58 23.11 +25 39 07.2 16.64 R is following: T0+ Filter, Exposure, mag., err. (d) (s) R 51x60 22.10 +/- 0.08 We confirm the shallow decay of the afterglow (D. Xu et al., GCN 9809) with power law index ~0.3. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9903 SUBJECT: GRB 090814A: Skynet/DSO & GORT Observations DATE: 09/09/09 00:41:59 GMT FROM: Josh Haislip at U.North Carolina J. Haislip, D. Reichart, K. Ivarsen, A. Smith, D. Caton, L. Hawkins, L. Cominsky, K. McLin, T. Graves, G. Spear, A. LaCluyze, A. Foster, J. Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M. Nysewander report: Skynet observed the Swift/BAT localization of GRB 090814A (Ukwatta et al., GCN 9793) with the 14" Dark Sky Observatory telescope in North Carolina beginning 71.1 minutes after the trigger in RI through variable cloud cover. Skynet continued observing with the 14" GORT telescope at Hume Observatory in California beginning 3.3 hours after the the trigger in RI. We do not detect the afterglow (Updike et al., GCN 9794). Stacking only images that increase the limiting magnitude yields: mean time 3-sigma secondary since limiting calibration trigger telescope exposures filter magnitude stars * 75.4 m DSO-14 2 x 160 s I 18.5 13 SDSS 6 + 1 x 80 s 86.4 m DSO-14 4 x 160 s R 19.2 9 SDSS 6 96.6 m DSO-14 3 x 160 s I 17.8 13 SDSS 6 105.3 m DSO-14 1 x 160 s R 16.9 9 SDSS 6 4.7 h GORT 35 x 80 s I 20.1 8 SDSS 6 5.2 h GORT 40 x 80 s R 20.8 7 SDSS 6 24.9 h DSO-14 11 x 160 s R 20.0 9 SDSS 6 * Transformed using Jester et al., 2005, ApJ, 130, 873.