//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16118 SUBJECT: GRB 140419A: Swift detection of a burst with optical afterglow DATE: 14/04/19 04:21:34 GMT FROM: Caryl Gronwall at PSU/Swift-UVOT F. E. Marshall (NASA/GSFC), J. R. Cummings (NASA/UMBC), C. Gronwall (PSU), J. A. Kennea (PSU), A. Maselli (INAF-IASFPA), T. Sakamoto (AGU), M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift Team: At 04:06:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140419A (trigger=596426). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 126.999, +46.221 which is RA(J2000) = 08h 28m 00s Dec(J2000) = +46d 13' 15" 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 80 sec. The peak count rate was ~5611 counts/sec (15-350 keV), at ~52 sec after the trigger. The XRT began observing the field at 04:08:17.5 UT, 86.5 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 126.9909, 46.2416 which is equivalent to: RA(J2000) = +08h 27m 57.82s Dec(J2000) = +46d 14' 29.8" with an uncertainty of 4.8 arcseconds (radius, 90% containment). This location is 76 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 5.09e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 96 seconds after the BAT trigger. A bright uncatalogued source is identified in the 2.7'x2.7' sub-image near the position of the XRT afterglow. However, a more precise position is unavailable at this time. The approximate magnitude in the White filter is 16.1. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03. Burst Advocate for this burst is F. E. Marshall (marshall 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: 16119 SUBJECT: GRB 140419A (Swift trigger 596426) : KAIT optical candidate DATE: 14/04/19 04:29:15 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift trigger 596426. A bright (R~13.5) optical counterpart un-cataloged in DSS image was detected at location of Ra, DEC (J2000): 08:27:57.56 +46:14:25.11 with uncertainty of about 1". We suggest this to be the afterglow of the GRB. Follow-up observations encouraged. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16120 SUBJECT: GRB 140419A: ROTSE-III Detection of Optical Counterpart DATE: 14/04/19 04:40:43 GMT FROM: Tolga Guver at UA GRB 140419A: ROTSE-III Detection of Optical Counterpart T. Guver (Istanbul Univ.), F. V. Ferrante (SMU), H. Flewelling (IfA/Hawaii), R. Kehoe (SMU), G. Dhungana (SMU) report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 140419A (Swift trigger 596426, GCN 16118). The first image was at 04:07:18.7 UT, 27.3 s after the burst (8.7 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a new object, not visible in the DSS (second epoch), with coordinates: 08:27:57.7 +46:14:25.9 (J2000), with positional uncertainty of 1' or better start UT mag mlim(of image) ---------------------------------- 04:07:18.7 13.5 15.0 The object first detected with a magnitude of ~13.5, brightened to 12.5 magnitudes in ~70 seconds then the brightness decayed fast to ~14.3 magnitudes at about 350 seconds. A jpeg image is available at http://www.rotse.net/images/gsq596426_3b01_img.jpg Note that the object marked 8 is the candidate in question. Continuing observations are in progress. ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16121 SUBJECT: GRB 140419A: RATIR Optical and NIR Observations DATE: 14/04/19 05:30:28 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 140419A (Marshall, et al., GCN 16118) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/04 19.18 to 2014/04 19.20 UTC (9 to 40 minutes after the BAT trigger), obtaining a total of 0.36 hours exposure in the r and i bands and 0.15 hours exposure in the Z, Y, J, and H bands. We detect the UVOT optical transient (see also, Zheng, et al., GCN 16116; Guver et al., GCN 16120). In comparison with the SDSS DR9 and 2MASS, we obtain the following detections: r 16.22 +/- 0.01 i 15.81 +/- 0.01 Z 15.66 +/- 0.01 Y 15.46 +/- 0.02 J 15.31 +/- 0.01 H 15.26 +/- 0.02 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The source appears to be fading approximately as t^(-1) in all of our bands during the observation. Further observations are ongoing. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16122 SUBJECT: GRB 140419A: CARMA early 3mm detection DATE: 14/04/19 07:07:57 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) reports on behalf of a larger collaboration: We observed the location of GRB 140419A (Marshall et al., GCN 16118) with the Combined Array for Research in Millimeter Astronomy at a mean frequency of 93 GHz starting at 05:23:45, 77 minutes after the GRB trigger. In the first hour of observations, we marginally detect a weak source consistent with the location of the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120) with a flux of approximately 1.5 mJy. Observations are continuing. We thank J. Carpenter and D. Segura-Cox for assistance with rapidly scheduling and executing the observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16123 SUBJECT: GRB140419A: UVOT detects fading afterglow in white but not in u filter DATE: 14/04/19 07:56:22 GMT FROM: Paul Kuin at MSSL NPM Kuin (MSSL-UCL), and F. E. Marshall (NASA/GSFC) report on behalf of the Swift Team: UVOT started observing GRB 140419A starting 96 seconds after the BAT trigger. The initial finding chart exposures with the White and U filter show a fading source in the white filter which we identify with the afterglow: The estimated magnitudes are as follows: filter starttime endtime magnitude error wh 96 246 16.01 0.06 u 308 558 >19.6 wh 862 1012 17.96 0.09. The source is not seen in the u filter, which suggests a redshift larger then 2.8. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16124 SUBJECT: GRB 140419A: Enhanced Swift-XRT position DATE: 14/04/19 11:56:14 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 3698 s of XRT Photon Counting mode data and 7 UVOT images for GRB 140419A, 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 = 126.98969, +46.24009 which is equivalent to: RA (J2000): 08h 27m 57.53s Dec (J2000): +46d 14' 24.3" with an uncertainty of 1.5 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: 16125 SUBJECT: GRB 140419A: Gemini-N redshift DATE: 14/04/19 13:21:37 GMT FROM: Nial Tanvir at U.Leicester N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), A. Cucchiarra (ORAU/GSFC), D. Perley (Caltech), S. B. Cenko (GSFC) D. Coulson, L. Fuhrman report: We observed the afterglow of GRB 140419A (Marshall et al. GCN 16118; Zheng et al. GCN 16119; Guver et al. GCN 16120; Butler et al. GCN 16121) with the GMOS-N spectrograph on Gemini-N. Observations began at 06:24 UT, approximately 2.3 hr post burst, and two different settings covered a total wavelength range from about 4400AA to 10100AA. The spectra reveal several strong absorption lines and in particular there is a marked break at about 6027 AA which we identify as Ly-a at a redshift z=3.956. Blueward is a clear Ly-a forest. At the same redshift we see strong lines of CIV (1548/1551) and SiIV (1394/1403), and weaker lines of NV (1239/1243), CII (1335), SiII (1527), AlII (1671). We therefore infer z=3.956 as the redshift of the burst. We note that there also appears to be an intervening system at z=2.686. [GCN OPS NOTE(19apr14): Per author's request, DC and LF were added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16126 SUBJECT: GRB 140419A: T24 optical observations DATE: 14/04/19 13:23:00 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill Observatory, Varkaus, Finland) report: We have detected GRB 140419A optical afterglow at iTelescope observatory T24 (Auberry, California) using 0.61-m/6.5 astrograph and FLI-PL09000 CCD. The observations were started at 2014-04-19 06:34:54 (UT) and stopped at 06:56:31 (UT). Four unfiltered images with 300 sec exposure time were made. The afterglow was detected at the following position RA 08:27:57.56 and DEC +46:14:25.2. The following magnitude was obtained from the observations using NOMAD1 1362-0196617 (R=17.110) as a comparison star: Tmid(s)+T0 Filter Exp. time Mag Mag err. 9536 unfiltered 4x300s 17.86CR 0.12 --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16127 SUBJECT: GRB 140419A: Swift-BAT refined analysis DATE: 14/04/19 15:19:34 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+485 sec from recent telemetry downlinks, we report further analysis of BAT GRB 140419A (trigger #596426) (Marshall, et al., GCN Circ. 16118). The BAT ground-calculated position is RA, Dec = 127.001, 46.234 deg, which is RA(J2000) = 08h 28m 00.4s Dec(J2000) = +46d 14' 03.7" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 33%. The mask-weighted light curve shows two slightly overlapping clusters of peaks, starting at ~T-10 sec, peaking at ~T+10 and ~T+51 sec, and ending at ~T+220 sec. T90 (15-350 keV) is 94.7 +- 11.0 sec (estimated error including systematics). The time-averaged spectrum from T-8.69 to T+222.32 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.21 +- 0.04. The fluence in the 15-150 keV band is 1.59 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+51.42 sec in the 15-150 keV band is 4.9 +- 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/596426/BA/ [GCN OPS NOTE(22apr14): Per author's request, the fluence value was changed from "1.6 +- 0.0" to "1.59 +- 0.03". Acknowledgement to F.Marshall for pointing out the missing error value.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16128 SUBJECT: GRB 140419A: Swift-XRT refined Analysis DATE: 14/04/19 17:31:39 GMT FROM: Alessandro Maselli at INAF/IASF Palermo A. Maselli, M. De Pasquale (INAF-IASFPA), P. A. Evans (U Leicester) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team: We have analysed 10 ks of XRT data for GRB 140419A (Marshall et al. GCN Circ. 16118), from 79 s to 24.3 ks after the BAT trigger. The data comprise 849 s in Windowed Timing (WT) mode (the first 5 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 16124). The late-time light curve (from T0+5.4 ks) can be modelled with a power-law decay with a decay index of alpha=1.29 (+/-0.07). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.803 (+0.029, -0.028). The best-fitting absorption column is 1.7 (+2.8, -1.7) x 10^21 cm^-2, at a redshift of 3.956, in addition to the Galactic value of 3.9 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.83 (+/-0.06) and a best-fitting absorption column of 1.2 (+/-0.6) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 3.9 x 10^20 cm^-2 Intrinsic column: 1.2 (+/-0.6) x 10^22 cm^-2 at z=3.956 Photon index: 1.83 (+/-0.06) If the light curve continues to decay with a power-law decay index of 1.29, the count rate at T+24 hours will be 0.042 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x 10^-12 (1.7 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00596426. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16129 SUBJECT: GRB 140419A: P60 Observations DATE: 14/04/19 20:26:32 GMT FROM: S. Bradley Cenko at NASA/GSFC S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a larger collaboration: We observed the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126) of the Swift GRB 140419A (Marshall et al., GCN 16118) with the robotic Palomar 60 inch telescope. Observations were obtained in the r', i', and z' filters beginning at 4:40 UT on 2014 April 19 (33 minutes after the Swift trigger). The optical afterglow is clearly detected in all three filters. Using nearby point sources from SDSS for calibration, we measure the following magnitudes in our initial images: r' = 16.91 +/- 0.03 at dt = 33.7 min i' = 16.56 +/- 0.03 at dt = 35.1 min z' = 16.45 +/- 0.04 at dt = 36.5 min The redder r'-i' color is consistent with the Lyman break falling in the observed r' bandpass, as reported by Tanvir et al. (GCN 16125). Further observations are planned. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16130 SUBJECT: GRB 140419A: Swift UVOT refined analysis DATE: 14/04/19 21:55:33 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140419A 97 s after the BAT trigger (Marshall et al. GCN Circ. 16118). Optical and IR photometry and positions were reported, as well as a redshift (Cenko, et al., GCN Circ. 16129; Hentunen et al., GCN Circ. 16126; Tanvir et al., GCN Circ. 16125; Kuin et al., GCN Circ. 16123; Butler et al., GCN Circ. 16121; Guver et al., GCN Circ. 16120; and Zheng et al., GCN Circ. 16119.) A source consistent with the XRT position is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:27:57.56 = 126.98982 (deg.) Dec (J2000) = +46:14:25.3 = 46.24037 (deg.) with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence). Due to the GRB lying on the edge of a large scattered light feature from the bright star nearby, photometry errors are large until a good background template can be made at late times. 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 97 246 147 16.2 +/- 0.2 v 638 658 19 16.1 +/- 0.2 b 564 756 39 18.4 +/- 0.2 u 309 2003 362 >21.0 w1 687 707 19 >18.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16131 SUBJECT: GRB 140419A: MITSuME Okayama Optical Observation DATE: 14/04/20 07:34:30 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 140419A (Marshall et al., GCNC 16118) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2014-04-19 11:17:09 UT (~7.2 h after the burst). We detected the previously reported afterglow (Marshall et al., GCNC 16118; Zheng et al., GCNC 16119) in Rc and Ic bands. Three sigma upper limit and photometric results of the OT are listed below. We used SDSS catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic Ic_err ----------------------------------------------------------------------- 0.36126 12:47:03 8700.0 >20.1 19.8 0.3 19.1 0.3 ------------------------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16132 SUBJECT: GRB 140419A: MITSuME Ishigakijima Optical Observation DATE: 14/04/20 10:22:25 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 140419A (Marshall et al., GCNC 16118) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2014-04-19 12:40:26 UT (~8.6 h after the burst). We detected the previously reported afterglow (Marshall et al., GCNC 16118; Zheng et al., GCNC 16119) in all the three bands. Photometric results of the OT are listed below. We used SDSS catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err ---------------------------------------------------------------------- 0.39781 13:39:41 5820.0 20.6 0.1 19.5 0.1 19.1 0.1 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16133 SUBJECT: GRB 140419A, Optical Observations DATE: 14/04/20 14:50:33 GMT FROM: Shashi Bhushan Pandey at ROTSE S. B. Pandey and Brajesh Kumar (ARIES Nainital India, on behalf of larger Indian GRB collaboration) We observed the Swift GRB 140419A field (Marshall et al., GCN 16118) using 1.04m ST telescope at ARIES Nainital. Observations were started at 14:44:38 UT on 2014-04-19 (approximately 10.6 h after the burst). Several frames with an exposure time of 300 s each in R_c band were obtained in good sky conditions. The optical counterpart of GRB 140419A (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al.,GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126; Cenko et al., GCN 16129) is clearly detected in each individual frames. The preliminary photometry of the first frame is 19.8 +- 0.1 mag. The photometry was performed in comparison to nearby USNO stars. This massage may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16134 SUBJECT: Konus-Wind observation of GRB 140419A DATE: 14/04/20 15:07:10 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline on behalf of the Konus-Wind team, report: The long-duration, intense GRB 140419A (Swift-BAT trigger #596426: Marshal et al., GCN 16118; Baumgartner et al., GCN 16127) triggered Konus-Wind at T0=14811.110 s UT (04:06:51.110). The burst light curve shows a broad, hard-spectrum pulse from ~T0-10 s to ~T0+40 s and a complex of narrow, softer pulses around ~T0+50 s. The total duration of the burst is ~80 s. The emission is seen up to several MeV, however the energy channels above ~2 MeV are strongly affected by the high and variable solar particle background. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB140419_T14811/ As observed by Konus-Wind, the burst had a fluence of 5.8(-1.9,+2.8)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+7.744 s, of 4.7(-1.9,+1.8)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+76.032 s) is best fit in the 20 keV - 1.9 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.63 (-0.22,+0.36), the high energy photon index beta = -2.3 (-2.5,+0.4), the peak energy Ep = 293 (-84,+84) keV, chi2 = 51.1/59 dof. The spectrum near the maximum count rate (measured from T0+6.144 to T0+17.408 s) is best fit in the 20 keV - 1.9 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.52 (-0.20,+0.24), the high energy photon index beta = -2.3 (-2.7,+0.4), the peak energy Ep = 363 (-75,+96) keV, chi2 = 70.7/60 dof. Assuming the redshift z=3.956 (Tanvir et al., GCN 15645) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~1.9x10^54 erg, the peak luminosity L_iso is ~7.5x10^53 erg/s, and the rest-frame peak energy Ep,i is ~1450 keV. These estimates place GRB 140419A among the most energetic GRBs. All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16136 SUBJECT: GRB 140419A: Continued RATIR Optical and NIR Observations DATE: 14/04/21 01:18:52 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 140419A (Marshall, et al., GCN 16118) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/04 20.14 to 2014/04 20.29 UTC (23.23 to 26.83 hours after the BAT trigger), obtaining a total of 2.49 hours exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H bands. We continue to detect the UVOT optical transient (Zheng, et al., GCN 16116; Guver et al., GCN 16120). For a source within the GCN-16119 error circle, in comparison with the SDSS DR9 and 2MASS, we obtain the following detections: r 21.35 +/- 0.04 i 20.76 +/- 0.04 Z 20.61 +/- 0.06 Y 20.45 +/- 0.07 J 20.35 +/- 0.08 H 20.32 +/- 0.10 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to the previous epoch of RATIR observations (Butler, et al., GCN 16121) we find that the source has continued to fade with an approximate power-law index of alpha = 1.2 in all six bands. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16137 SUBJECT: GRB 140419A: KAIT Refined Analysis DATE: 14/04/21 05:21:29 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory responded to Swift GRB 140419A (Marshall et al., GCN 16118) starting at 04:10:00 UT, 189 s after the burst. Observations were performed with an automatic sequence in the V, I, and clear (roughly R) filters, and the exposure time was 20 s per image. The bright optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120) was well detected in all three filters. Preliminary analysis shows that the afterglow decays with a single power law (with alpha = -1.15) from the beginning of our observations until about 3 hours later when the position moved beyond our reach. The power-law index is consistent with the value reported by Butler et al. (GCN 16121; GCN 16136). We find (V - I) about 1.7 mag (no extinction correction), and no obvious color change was detected during our observations. A preliminary light curve is posted at http://astro.berkeley.edu/~zwk/grb/GRB140419A/GRB140419A_kait.png //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16138 SUBJECT: GRB140419A: NOT optical observations DATE: 14/04/21 17:59:57 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), T. Kruehler (ESO), N. Tanvir (U. Leicester), F. Taddia, C. Fremling (Stockholm U.) report on behalf of a larger collaboration: We observed the optical afterglow of GRB 140419A (Marshall et al., GCN 16118; Zheng et al., GCN 16119; Kuin et al., GCN 16123) using the 2.5 Nordic Optical Telescope equipped with ALFOSC. We obtained 4x300s, 3x300s, 4x200s frames in the SDSS g-, r-, and i-filters, respectively, with floating clouds, starting at 23:10 UT on 2014-04-20 . Photometry is calibrated with nearby SDSS stars, and results are as follows: Tmid-T0(hr) Mag MagErr 43.24 >22.5 43.54 23.16 0.15 43.86 >20.3 Compared with previous measurements (e.g., from RATIR and KAIT), the afterglow may be decaying more quickly. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16139 SUBJECT: GRB 140419A: Continued RATIR Optical and NIR Observations DATE: 14/04/21 19:19:13 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 140419A (Marshall, et al., GCN 16118) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/04 21.14 to 2014/04 21.29 UTC (47.30 to 50.93 hours after the BAT trigger), obtaining a total of 2.49 hours exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H bands. We continue to detect the UVOT optical transient (Zheng, et al., GCN 16116; Guver et al., GCN 16120). For a source located at the position of the KAIT optical counterpart candidate (Zheng, et al., GCN 16119), in comparison with the SDSS DR9 and 2MASS, we obtain the following detections and upper limit (3-sigma): r 21.92 +/- 0.07 i 21.77 +/- 0.07 Z 21.74 +/- 0.13 Y 21.58 +/- 0.19 J 21.54 +/- 0.21 H > 21.66 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to the first two epochs of RATIR observations (Littlejohns, et al., GCN 16136; Butler, et al., GCN 16121) we note that the decay in the NIR bands appears steeper, now consistent with 1.4 < alpha < 1.6 in the i, Z, Y, J and H bands (see also; Xu et al., GCN 16138). The XRT data for this GRB (http://www.swift.ac.uk/xrt_curves/00596426/) may support a temporal break at low significance after 100 ks. Further XRTdata can constrain this possibility. Conversely, the decay observed in the r band has become shallower, with alpha = 0.8. This shallow decay in the r band could be attributed to the presence of an underlying host galaxy or contamination from the nearby bright star. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16140 SUBJECT: GRB 140419A: Refined NOT photometry DATE: 14/04/21 20:30:09 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI) reports: The photometry of the NOT SDSS r-band data in GCN 16138 has been refined. The detected object is not point-like but somewhat extended in the NOT image. The photometry in GCN 16138 only covers a seemingly bright part of the extended object. If the whole object is covered, the brightness changes to m(R)=21.60+/-0.20 calibrated with the same nearby SDSS stars, which now is consistent with the decaying law derived from pre- and post-NOT observations (e.g., from RATIR; GCN 16139). We thank Antonino Cucchiara for pointing out the difference in magnitudes. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16141 SUBJECT: GRB 140419A: Mondy optical observations DATE: 14/04/22 14:44:54 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 140419A (Marshall et al., GCN 16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr. 19-21. We took several images in R-filter of 60 s exposure. On stacked images we clearly detected the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126) except the combined image of Apr. 19 due to unfavorable weather conditions. Our photometry is consistent with the decaying law derived from RATIR observations (Littlejohns et al., GCNs 16139, 16136). The details of the photometry are the following: date UT start t-T0 Filter Exp. OT Uplim (mid, days) (s) 3sigma 2014-04-19 16:26:35 0.52030 R 10*60 n/d 19.3 2014-04-20 14:49:15 1.47495 R 83*60 21.12 +/- 0.10 21.6 2014-04-21 14:58:36 2.49015 R 107*60 21.60 +/- 0.15 22.2 The photometry is based on nearby SDSS star, R (gri -> R transformations by Lupton 2005): SDSS id R J082752.69+461357.4 17.381 +/- 0.018 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16149 SUBJECT: GRB 140419A, LOAO R-band observations DATE: 14/04/23 12:04:51 GMT FROM: Changsu Choi at Seoul Nat U Changsu Choi, Myungshin Im (CEOU/SNU), Hyun-Il Sung (KASI), and Yuji Urata (NCU), on behalf of EAFON We observed the field of GRB 140419A Swift GRB 140419A (Marshall et al., GCN 16118) in R-band using the 1-m telescope at Mt. Lemmon Optical Observatory (LOAO) in Arizona, US We obtained R-band images at two epochs on Apr. 19 and on Apr. 21. We marginally identify the afterglow in a stacked image for each night. The photometry is based on R1-mag of USNO-B1 stars in the observed field. Details of Photometry are below: date UT(mid time) Filter mag 2014/04/19 07:30:51 R 18.64 +/-0.29 2014/04/21 03:39:38 R 21.43 +/-0.27 We thank the LOAO operator, Jae-Hyuk Yoon for performing the observation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16168 SUBJECT: GRB 140419A: Continued Mondy optical observations DATE: 14/04/24 15:28:48 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We continued observation of the Swift GRB 140419A (Marshall et al., GCN 16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr. 19-21. We took several images in R-filter. On a stacked image we clearly detected the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126). Details of a photometry are the following: date UT start t-T0 Filter Exp. OT (mid, days) (s) 2014-04-22 14:49:26 3.45342 R 120*60 22.18 +/- 0.09 The photometry is based on nearby SDSS star, R (gri -> R transformations by Lupton 2005): SDSS id R J082752.69+461357.4 17.381 ± 0.018 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16281 SUBJECT: GRB 140419A: Continued Mondy optical observations DATE: 14/05/16 15:49:12 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We continued observation of the Swift GRB 140419A (Marshall et al., GCN 16118) with AZT-33IK telescope of Sayan observatory (Mondy) on Apr. 25-26. We took several images in R-filter with the exposure of 60 seconds. On a stacked image from Apr. 25 we detect the optical afterglow (Zheng et al., GCN 16119; Guver et al., GCN 16120; Butler et al., GCN 16121; Kuin et al., GCN 16123; Hentunen et al., GCN 16126). On the stacked frame from Apr. 26 in the Swift/XRT error circle (Osborne et al., GCN 16124) we do not detect any source. Details of a photometry are the following: date UT start t-T0 Filter Exp. OT (mid, days) (s) 2014-04-25 14:48:25 6.47713 R 90*60 22.81+/-0.17 2014-04-26 14:21:55 7.45841 R 90*60 >21.7 (3 sigma) The photometry is based on nearby SDSS star, R (gri -> R transformations by Lupton 2005): SDSS id R J082752.69+461357.4 17.381+/-0.018