//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16190 SUBJECT: GRB140430A: Swift detection of a burst with an optical counterpart DATE: 14/04/30 20:48:23 GMT FROM: Scott Barthelmy at NASA/GSFC M. H. Siegel (PSU), W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU), V. D'Elia (ASDC), S. T. Holland (STScI), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC) and T. N. Ukwatta (MSU) report on behalf of the Swift Team: At 20:33:36 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140430A (trigger=597722). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 102.929, +23.009 which is RA(J2000) = 06h 51m 43s Dec(J2000) = +23d 00' 34" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 10 sec. The peak count rate was ~4500 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 20:34:27.3 UT, 50.8 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 102.9359, 23.0227 which is equivalent to: RA(J2000) = +06h 51m 44.62s Dec(J2000) = +23d 01' 21.7" with an uncertainty of 4.9 arcseconds (radius, 90% containment). This location is 54 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 3.99e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 183 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 06:51:44.61 = 102.93589 DEC(J2000) = +23:01:25.2 = 23.02367 with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.5 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.16 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.14. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 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: 16192 SUBJECT: GRB 140430A : Liverpool Telescope optical afterglow observations DATE: 14/04/30 22:21:29 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana), R. J. Smith and C. G. Mundell (LJMU), on behalf of a large collaboration report: The 2-m Liverpool Telescope with the RINGO3 polarimeter robotically followed up Swift GRB 140430A (Siegel et al., GCN 16190) at 20:35:40 UT (~2 min after the burst trigger). We detect the optical afterglow at the UVOT position. In a coadded 3x10s SDSS-r image, we estimate a preliminary magnitude R = 18.4 +/- 0.1 at t_mid = 33.1 min since the Swift/BAT trigger time. The magnitude is calibrated against nearby USNO-B1 stars. Observations are ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16193 SUBJECT: GRB 140430A: NOT optical observations DATE: 14/04/30 23:43:05 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI), T. Kruehler (ESO Santiago), A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), H. Dahle (Univ. Oslo), E. Soto (CUA), report on behalf of a larger collaboration: We observed the optical afterglow of GRB 140430A (Siegel et al., GCN 16190; Melandri et al., GCN 16192) with the Nordic Optical Telescope equipped with ALFOSC. We took a single 100-s image in the R filter starting at 22:00 UT (86.5 min after the GRB). The optical afterglow is well detected at coordinates (J2000): RA = 06:51:44.61 Dec = +23:01:25.1 with an uncertainty of 0.3". Assuming R = 15.13 for the USNO star at RA = 06:51:41.3, Dec = +23:01:44.0, we measure for the optical afterglow a magnitude R = 18.78 +- 0.02 (statistical error only). A 1800-s spectrum was acquired starting at 22:11 UT, at airmass 2.2-2.8, covering the wavelength range 3200-9100 AA. From a preliminary analysis, no absorption or emission features are seen in the spectrum. From the lack of a DLA feature down to ~4000 AA, we can set a redshift limit z < 2.3. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16194 SUBJECT: GRB 140430A: VLT/X-shooter redshift DATE: 14/05/01 00:54:33 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst T. Kruehler (ESO Santiago), D. Malesani (DARK/NBI), A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), A. Melandri (INAF/OABr), J. P. U. Fynbo (DARK/NBI), report on behalf of a larger collaboration: We observed the optical afterglow of GRB 140430A (Siegel et al., GCN 16190) with the ESO VLT equipped with X-shooter. Observations started at 23:09 UT on 2014 April 30 (2.5 hr after the GRB), still in twilight, and two 10-minute spectra were secured. The covered wavelength range is 3000-25000 AA. We detect a clear continuum, and several absorption features, which we interpret as due, among others, to Si II, C IV, Al II, Fe II, and Mg II at a common redshift z = 1.60. In the infrared arm, we also detect the [O III] 5008 nebular line in emission at the same redshift. We acknowledge excellent support from the ESO staff at Paranal, in particular Andrea Mehner, Rodrigo Romero, and Stephane Brillant. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16195 SUBJECT: GRB 140430A: Enhanced Swift-XRT position DATE: 14/05/01 04:15:54 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 1017 s of XRT Photon Counting mode data and 3 UVOT images for GRB 140430A, 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 = 102.93576, +23.02375 which is equivalent to: RA (J2000): 06h 51m 44.58s Dec (J2000): +23d 01' 25.5" with an uncertainty of 1.9 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: 16196 SUBJECT: GRB 140430A: VATT Optical Observations DATE: 14/05/01 06:43:27 GMT FROM: Peter Garnavich at U of Notre Dame M. Kennedy (University College Cork), P. Garnavich (Notre Dame) We observed the region around GRB 140430A with the 1.8m Vatican Advanced Technology Telescope (VATT) on 2014 May 1 (UT). With the VATT4K CCD we obtained 5x120s exposures in the R-band centered around 03:22UT (408 mins after the GRB). A source not seen in the Digitized Sky Survey is well-detected at the coordinates reported by Malesani et al (GCN 16193). Relative photometry was carried out using the same nearby star used by Malesani et al. which has an R-band magnitude of R=15.13. Our R-band magnitude for the GRB, 6.81 hours after the initial outburst, is R=20.07 +- 0.03. Combining our results with the magnitude from GCN 16193 we estimate an optical power-law decay index of 0.76. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16197 SUBJECT: GRB 140430A: Swift-XRT refined Analysis DATE: 14/05/01 09:48:09 GMT FROM: Phil Evans at U of Leicester M.C. Stroh (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU) and M.H. Siegel report on behalf of the Swift-XRT team: We have analysed 7.0 ks of XRT data for GRB 140430A (Siegel et al. GCN Circ. 16190), from 132 s to 23.5 ks after the BAT trigger. The data comprise 382 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 16195). The late-time light curve (from T0+3.8 ks) can be modelled with a power-law decay with a decay index of alpha=0.68 (+0.12, -0.13). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.05 (+/-0.04). The best-fitting absorption column is 3.7 (+1.4, -1.3) x 10^21 cm^-2, at a redshift of 1.6, in addition to the Galactic value of 2.1 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.21 (+0.20, -0.19) and a best-fitting absorption column of 5.3 (+6.5, -5.3) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.3 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 2.1 x 10^21 cm^-2 Intrinsic column: 5.3 (+6.5, -5.3) x 10^21 cm^-2 at z=1.6 Photon index: 2.21 (+0.20, -0.19) If the light curve continues to decay with a power-law decay index of 0.68, the count rate at T+24 hours will be 0.018 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.0 x 10^-13 (9.6 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/00597722. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16198 SUBJECT: GRB 140430A: Swift/UVOT Observations DATE: 14/05/01 11:42:29 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140430A 183 s after the BAT trigger (Siegel et al., GCN Circ. 16190). A fading source consistent with the refined XRT position (Evans et al. GCN Circ. 16195) is confirmed in the initial UVOT exposures. The detection in the uvw1 filter, but not in uvm2 and uvw2 is consistent with the redshift of 1.6 given by Kruehler et al., (GCN Circ. 16194). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 183 333 147 18.17 ± 0.09 white 4020 4220 197 19.61 ± 0.17 v 417 4630 216 >18.6 b 3815 4015 197 19.77 ± 0.34 u 10431 10933 490 19.46 ± 0.19 uvw1 6178 10424 966 20.40 ± 0.31 uvm2 442 4835 216 >19.9 uvw2 393 4425 216 >19.4 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.14 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16200 SUBJECT: GRB 140430A: Swift-BAT refined analysis DATE: 14/05/01 21:30:21 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), N. Gehrels (GSFC), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. H. Siegel (PSU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-152 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140430A (trigger #597722) (Siegel, et al., GCN Circ. 16190). The BAT ground-calculated position is RA, Dec = 102.942, 23.033 deg, which is RA(J2000) = 06h 51m 46.0s Dec(J2000) = +23d 01' 58.2" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows several well separated peaks. The first (and brightest) starts at ~T-1 sec, peaks at ~T+4 sec, and ends at ~T+9 sec. The 2nd and 3rd peaks peak at ~T+30 and ~T+180, respectively. T90 (15-350 keV) is 173.6 +- 3.7 sec (estimated error including systematics). The time-averaged spectrum from T-0.30 to T+177.58 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.00 +- 0.22. The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.44 sec in the 15-150 keV band is 2.5 +- 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/597722/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16201 SUBJECT: GRB 140430A: Further VATT Optical Observations DATE: 14/05/02 07:41:32 GMT FROM: Peter Garnavich at U of Notre Dame M. Kennedy (University College Cork), P. Garnavich (Notre Dame) We again observed the field around GRB 140430A with the 1.8m Vatican Advanced Technology Telescope (VATT; GCN 16196). Observations with the VATT4K CCD were centered around 3:22 UT on 2014 May 2 (1848 minutes after the burst). We obtained 5x300s exposures with the R-band filter in good seeing. We detect the previously reported afterglow in the combined images. With the same USNO comparison star used by Malesani et al (GCN 16193) and Kennedy et al. (GCN 16196) we estimate the afterglow brightness as R=21.7 +/- 0.1 at 30.81 hours after the burst. This is fainter than the extrapolation of the power-law decay rate estimated for the first seven hours and we conclude that optical power-law decay index has steepened to 1.0 over the past day. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16205 SUBJECT: GRB 140430A: BVR-band IAC80 observations DATE: 14/05/02 17:44:33 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC/UPV-EHU), E. Gomez (IAC), P.A. Gonzalez-Morales (IAC), J. Cepa (IAC), report on behalf of a larger collaboration: "We observed the field of GRB 140430A (Siegel et al. GCN 16190) with the 0.82m IAC80 telescope located at Observatorio del Teide, Tenerife, Spain. The observations were carried on April 30.87401-30.88509 UT (25.0-40.9 min post burst) using the BVR-band filters. The optical afterglow is clearly detected in the three bands with a preliminary Vega magnitude of B=19.3 against the USNO B1.0 catalogue." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16211 SUBJECT: GRB 140430A: r'-band STELLA-I observations DATE: 14/05/03 12:29:59 GMT FROM: Arto Jarvinen at AIP A. Järvinen (AIP) and J. Gorosabel (IAA-CSIC/UPV-EHU), report on behalf of larger collaborations: "The field of GRB 140430A (Siegel et al. GCN 16190) was observed with WiFSIP on STELLA-I telescope located at Observatorio del Teide, Tenerife, Spain. The automatic observations were carried out on April 30., 2.9-32.5 min post trigger using the r'-band filter. The object is clearly detected in all 52 images with preliminary r'(AB) magnitudes ranging from ~17.0 to ~18.6 calibrated against the USNO B1.0 catalogue." [GCN OPS NOTE(03may14): The distribution was delayed by 3 hours due to a stale address in the vetting list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16212 SUBJECT: GRB 140430A: iTelescope.Net T16 Optical Observation DATE: 14/05/04 12:18:49 GMT FROM: Takanori Sakamoto at AGU T. Sakamoto, D. Kawamura, A. Yoshida (AGU) We observed the field of GRB 140430A detected by Swift (trigger #597722; Siegel et al., GCN Circ. 16190) with the iTelescope.Net (http://www.itelescope.net) T16 (15 cm Takahashi TOA-150) telescope located at the AstroCamp Observatory (Nerpio, Spain). Due to the elevation constraint, we were able to collect only 4 images of 60 sec exposures in the R filter starting from April 30 20:46:42 (UT) about 13 minutes after the trigger and stopped on April 30 20:52:42 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the reported optical afterglow position (Siegel et al., GCN Circ. 16190; Malesani et al., GCN Circ. 16193). The estimated five sigma upper limit of the combined image (total exposure of 240 sec) is ~18.6 using the USNO-B1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16222 SUBJECT: GRB 140430A: MITSuME Akeno upper limits DATE: 14/05/08 03:53:34 GMT FROM: Taketoshi Yoshii at Tokyo Tech T. Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, S. Kurita, Y.Ono , Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 140430A (Siegel et al. , GCN Circular #16190) with the optical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2014-05-01 10:57:06 UT ( 14.4 h after the burst). We did not find any new point source within the enhanced XRT circle (Evans et al., GCNC 16195) in all the three bands. The measured magnitudes were listed below. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic --------------------------------------------------------------------------------------- 54229 11:37:25 3540 >19.2 >19.5 >19.2 --------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.