Gamma-ray Burst 160424A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 11:49:32 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     683906,   Seg_Num: 0
  GRB_RA:          319.481d {+21h 17m 55s} (J2000),
                   319.793d {+21h 19m 10s} (current),
                   318.517d {+21h 14m 04s} (1950)
  GRB_DEC:         -60.405d {-60d 24' 18"} (J2000),
                   -60.336d {-60d 20' 09"} (current),
                   -60.615d {-60d 36' 54"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       5079 [cnts]    Image_Peak=445 [image_cnts]
  TRIGGER_DUR:     1.024 [sec] 
  TRIGGER_INDEX:   150     E_range: 25-100 keV
  BKG_INTEN:       21796 [cnts]
  BKG_TIME:        42535.82 SOD {11:48:55.82} UT
  BKG_DUR:         8 [sec]
  GRB_DATE:        17502 TJD;   115 DOY;   16/04/24
  GRB_TIME:        42547.34 SOD {11:49:07.34} UT
  GRB_PHI:         172.69 [deg]
  GRB_THETA:        44.36 [deg]
  SOLN_STATUS:     0x20000003
  RATE_SIGNIF:     43.50 [sigma]
  IMAGE_SIGNIF:    15.78 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +0  +2  +4  +0  +0  +5  +0 
  SUN_POSTN:        32.46d {+02h 09m 50s}  +13.10d {+13d 05' 47"}
  SUN_DIST:         93.05 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.37d {+15h 53m 29s}  -15.36d {-15d 21' 47"}
  MOON_DIST:        72.46 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.72,-41.20 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      300.39,-42.08 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 72.33,-20.07 [deg].  
  COMMENTS:           
  COMMENTS:        NOTE: This BAT event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=483191350).  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 11:49:36 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      47
  TRIGGER_NUM:     483191350
  GRB_RA:          312.700d {+20h 50m 48s} (J2000),
                   312.995d {+20h 51m 59s} (current),
                   311.791d {+20h 47m 10s} (1950)
  GRB_DEC:         -52.417d {-52d 25' 00"} (J2000),
                   -52.355d {-52d 21' 17"} (current),
                   -52.604d {-52d 36' 13"} (1950)
  GRB_ERROR:       6.40 [deg radius, statistical plus systematic]
  GRB_INTEN:       441 [cnts/sec]
  DATA_SIGNIF:     22.80 [sigma]
  INTEG_TIME:      1.024 [sec]
  GRB_DATE:        17502 TJD;   115 DOY;   16/04/24
  GRB_TIME:        42546.48 SOD {11:49:06.48} UT
  GRB_PHI:          60.00 [deg]
  GRB_THETA:        20.00 [deg]
  DATA_TIME_SCALE: 1.0240 [sec]
  HARD_RATIO:      0.62
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      96%  GRB
  2nd_MOST_LIKELY:   3%  Generic Transient
  DETECTORS:       1,0,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
  SUN_POSTN:        32.46d {+02h 09m 50s}  +13.10d {+13d 05' 48"}
  SUN_DIST:         94.05 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
  MOON_POSTN:      238.37d {+15h 53m 29s}  -15.36d {-15d 21' 47"}
  MOON_DIST:        68.53 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      345.95,-39.16 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      299.66,-33.28 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160424492/quicklook/glg_lc_medres34_bn160424492.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 237.97,-23.25 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=683906).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 11:49:44 UT
  NOTICE_TYPE:     Fermi-GBM Ground Position
  RECORD_NUM:      58
  TRIGGER_NUM:     483191350
  GRB_RA:          321.050d {+21h 24m 12s} (J2000),
                   321.341d {+21h 25m 22s} (current),
                   320.152d {+21h 20m 37s} (1950)
  GRB_DEC:         -55.410d {-55d 24' 35"} (J2000),
                   -55.339d {-55d 20' 20"} (current),
                   -55.625d {-55d 37' 30"} (1950)
  GRB_ERROR:       1.58 [deg radius, statistical only]
  DATA_SIGNIF:     29.60 [sigma]
  DATA_INTERVAL:   2.048 [sec]
  GRB_DATE:        17502 TJD;   115 DOY;   16/04/24
  GRB_TIME:        42546.48 SOD {11:49:06.48} UT
  GRB_PHI:          43.00 [deg]
  GRB_THETA:        19.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   4153 (Gnd S/W Version number)
  SUN_POSTN:        32.46d {+02h 09m 50s}  +13.10d {+13d 05' 48"}
  SUN_DIST:         90.41 [deg]   Sun_angle= 4.7 [hr] (West of Sun)
  MOON_POSTN:      238.37d {+15h 53m 29s}  -15.36d {-15d 21' 48"}
  MOON_DIST:        73.44 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      340.86,-43.45 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      303.99,-37.83 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160424492/quicklook/glg_lc_medres34_bn160424492.gif
  POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_483191350.fits
  COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
  COMMENTS:        In the LAT Field-of-view.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
  COMMENTS:        The POS_MAP_URL file will not be created/available until ~4 min after the notice.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=683906).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 11:50:16 UT
  NOTICE_TYPE:     Fermi-GBM Ground Position
  RECORD_NUM:      0
  TRIGGER_NUM:     483191350
  GRB_RA:          320.700d {+21h 22m 48s} (J2000),
                   320.995d {+21h 23m 59s} (current),
                   319.790d {+21h 19m 09s} (1950)
  GRB_DEC:         -56.490d {-56d 29' 23"} (J2000),
                   -56.420d {-56d 25' 09"} (current),
                   -56.704d {-56d 42' 14"} (1950)
  GRB_ERROR:       1.27 [deg radius, statistical only]
  DATA_SIGNIF:     27.50 [sigma]
  DATA_INTERVAL:   4.096 [sec]
  GRB_DATE:        17502 TJD;   115 DOY;   16/04/24
  GRB_TIME:        42546.48 SOD {11:49:06.48} UT
  GRB_PHI:          42.00 [deg]
  GRB_THETA:        18.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   41531 (Gnd S/W Version number)
  SUN_POSTN:        32.46d {+02h 09m 50s}  +13.10d {+13d 05' 48"}
  SUN_DIST:         91.00 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.38d {+15h 53m 31s}  -15.36d {-15d 21' 51"}
  MOON_DIST:        73.19 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      339.51,-42.97 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      303.22,-38.75 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160424492/quicklook/glg_lc_medres34_bn160424492.gif
  POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_483191350.fits
  COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
  COMMENTS:        In the LAT Field-of-view.  
  COMMENTS:        This is likely a Long GRB.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
  COMMENTS:        The POS_MAP_URL file will not be created/available until ~4 min after the notice.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=683906).  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 11:52:48 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     683906,   Seg_Num: 0
  GRB_RA:          319.481d {+21h 17m 55s} (J2000),
                   319.793d {+21h 19m 10s} (current),
                   318.517d {+21h 14m 04s} (1950)
  GRB_DEC:         -60.405d {-60d 24' 18"} (J2000),
                   -60.336d {-60d 20' 09"} (current),
                   -60.615d {-60d 36' 54"} (1950)
  GRB_DATE:        17502 TJD;   115 DOY;   16/04/24
  GRB_TIME:        42547.34 SOD {11:49:07.34} UT
  TRIGGER_INDEX:   150
  GRB_PHI:         172.69 [deg]
  GRB_THETA:        44.36 [deg]
  DELTA_TIME:      -31.00 [sec]
  TRIGGER_DUR:     1.024 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     43.50 [sigma]
  IMAGE_SIGNIF:    15.78 [sigma]
  LC_URL:          sw00683906000msb.lc
  SUN_POSTN:        32.46d {+02h 09m 50s}  +13.10d {+13d 05' 50"}
  SUN_DIST:         93.05 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.40d {+15h 53m 36s}  -15.37d {-15d 22' 04"}
  MOON_DIST:        72.44 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.72,-41.20 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      300.39,-42.08 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Lightcurve.  
  COMMENTS:           
  COMMENTS:        The next comments were copied from the BAT_POS Notice:  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 72.33,-20.07 [deg].  
  

  
• GCN Circular #19335
  A. Y. Lien (GSFC/UMBC), A. D'Ai (INAF-IASFPA), J. A. Kennea (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
  At 11:49:07 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160424A (trigger=683906). Swift did not immediately slew to the burst due to an observing constraint. The BAT on-board calculated location is RA, Dec 319.481, -60.405 which is

     RA(J2000) = 21h 17m 55s
     Dec(J2000) = -60d 24' 18"
  

  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 5 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger.
  Due to an observing constraint, Swift will not slew until T0+48.7 minutes. There will be no XRT or UVOT data until this time.
  Burst Advocate for this burst is A. Y. Lien (amy.y.lien 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.)
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 12:40:25 UT
  NOTICE_TYPE:     Swift-XRT Nack-Position
  TRIGGER_NUM:     683906,   Seg_Num: 0
  POINT_RA:        319.455d {+21h 17m 49s} (J2000)
  POINT_DEC:       -60.409d {-60d 24' 31"} (J2000)
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45602.10 SOD {12:40:02.10} UT,   3054.8 [sec] since BAT Trigger Time
  COUNTS:          1    Min_needed= 20
  STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
  PH2_ITER:        0    Max_iter_allowed= 4
  ERROR_CODE:      1
  COMMENTS:        SWIFT-XRT Nack Position.  
  COMMENTS:        No source found in the image.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 12:42:57 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     683906,   Seg_Num: 0
  POINT_RA:        319.455d {+21h 17m 49s} (J2000)
  POINT_DEC:       -60.409d {-60d 24' 31"} (J2000)
  POINT_ROLL:      68.982d
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45606.70 SOD {12:40:06.70} UT,   3059.4 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        2.080
  N_STARS:         102
  X_OFFSET:        568 [pixels]
  Y_OFFSET:        530 [pixels]
  X_MAX:           1527 [pixels]
  Y_MAX:           1489 [pixels]
  DET_THRESH:      12
  PHOTO_THRESH:    6
  SL_URL:          sw00683906000msufc3059.fits
  SUN_POSTN:        32.49d {+02h 09m 58s}  +13.11d {+13d 06' 31"}
  SUN_DIST:         93.09 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.82d {+15h 55m 18s}  -15.44d {-15d 26' 26"}
  MOON_DIST:        72.16 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.72,-41.19 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      300.37,-42.08 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 12:43:27 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     683906,   Seg_Num: 0
  POINT_RA:        319.455d {+21h 17m 49s} (J2000)
  POINT_DEC:       -60.409d {-60d 24' 31"} (J2000)
  POINT_ROLL:      68.982d
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45606.70 SOD {12:40:06.70} UT,   3059.4 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        2.080
  N_STARS:         102
  X_OFFSET:        568 [pixels]
  Y_OFFSET:        530 [pixels]
  X_MAX:           1527 [pixels]
  Y_MAX:           1489 [pixels]
  DET_THRESH:      12
  PHOTO_THRESH:    6
  SL_URL:          sw00683906000msufc3059.fits
  SUN_POSTN:        32.49d {+02h 09m 58s}  +13.11d {+13d 06' 32"}
  SUN_DIST:         93.09 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.83d {+15h 55m 19s}  -15.44d {-15d 26' 29"}
  MOON_DIST:        72.15 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.72,-41.19 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      300.37,-42.08 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Source List.  
  COMMENTS:        If you have elected to receive attachments:  
  COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 12:44:22 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     683906,   Seg_Num: 0
  POINT_RA:        319.455d {+21h 17m 49s} (J2000)
  POINT_DEC:       -60.409d {-60d 24' 31"} (J2000)
  ROLL:            68.982d
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45606.70 SOD {12:40:06.70} UT,   3059.4 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     483194422
  X_OFFSET:        887 [pixels]
  Y_OFFSET:        849 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       1047
  Y_GRB_POS:       1009
  BINNING_INDEX:   1
  IM_URL:          sw00683906000msuni3076.fits
  SUN_POSTN:        32.49d {+02h 09m 58s}  +13.11d {+13d 06' 32"}
  SUN_DIST:         93.09 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.84d {+15h 55m 21s}  -15.44d {-15d 26' 34"}
  MOON_DIST:        72.15 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.72,-41.19 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      300.37,-42.08 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Image.  
  COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 12:44:28 UT
  NOTICE_TYPE:     Swift-XRT Position
  TRIGGER_NUM:     683906,   Seg_Num: 0
  GRB_RA:          319.4800d {+21h 17m 55.20s} (J2000),
                   319.7924d {+21h 19m 10.18s} (current),
                   318.5164d {+21h 14m 03.94s} (1950)
  GRB_DEC:         -60.4116d {-60d 24' 41.7"} (J2000),
                   -60.3424d {-60d 20' 32.6"} (current),
                   -60.6217d {-60d 37' 18.1"} (1950)
  GRB_ERROR:       3.7 [arcsec radius, statistical plus systematic, 90% containment]
  GRB_INTEN:       1.00e-10 [erg/cm2/sec]
  GRB_SIGNIF:      10.00 [sigma]
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45641.00 SOD {12:40:41.00} UT,   3093.7 [sec] since BAT Trigger Time
  TAM[0-3]:        100.00 100.00 100.00 100.00
  AMPLIFIER:       1
  WAVEFORM:        31
  SUN_POSTN:        32.49d {+02h 09m 58s}  +13.11d {+13d 06' 32"}
  SUN_DIST:         93.08 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.84d {+15h 55m 21s}  -15.44d {-15d 26' 34"}
  MOON_DIST:        72.16 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.71,-41.20 [deg] galactic lon,lat of the burst
  ECL_COORDS:      300.38,-42.08 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Coordinates.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        TAM values, flux and significance fields are not valid.  
  COMMENTS:        This position was automatically generated on the ground using  
  COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
  COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
  COMMENTS:        The probability that this is a serendipitous source in the  
  COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 12:44:47 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     683906,   Seg_Num: 0
  POINT_RA:        319.455d {+21h 17m 49s} (J2000)
  POINT_DEC:       -60.409d {-60d 24' 31"} (J2000)
  ROLL:            68.982d
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45606.70 SOD {12:40:06.70} UT,   3059.4 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     483194422
  X_OFFSET:        887 [pixels]
  Y_OFFSET:        849 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       1047
  Y_GRB_POS:       1009
  BINNING_INDEX:   1
  IM_URL:          sw00683906000msuni3076.fits
  SUN_POSTN:        32.49d {+02h 09m 58s}  +13.11d {+13d 06' 33"}
  SUN_DIST:         93.09 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      238.84d {+15h 55m 22s}  -15.44d {-15d 26' 36"}
  MOON_DIST:        72.15 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.72,-41.19 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      300.37,-42.08 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Image.  
  COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  COMMENTS:        If you have elected to receive attachments:  
  COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 24 Apr 16 13:09:46 UT
  NOTICE_TYPE:     Swift-XRT Position UPDATE
  TRIGGER_NUM:     683906,   Seg_Num: 0
  GRB_RA:          319.4850d {+21h 17m 56.40s} (J2000),
                   319.7974d {+21h 19m 11.38s} (current),
                   318.5214d {+21h 14m 05.14s} (1950)
  GRB_DEC:         -60.4147d {-60d 24' 52.9"} (J2000),
                   -60.3455d {-60d 20' 43.7"} (current),
                   -60.6248d {-60d 37' 29.3"} (1950)
  GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
  GRB_INTEN:       1.00e-10 [erg/cm2/sec]
  GRB_SIGNIF:      10.00 [sigma]
  IMG_START_DATE:  17502 TJD;   115 DOY;   16/04/24
  IMG_START_TIME:  45641.00 SOD {12:40:41.00} UT,   3093.7 [sec] since BAT Trigger Time
  TAM[0-3]:        100.00 100.00 100.00 100.00
  AMPLIFIER:       1
  WAVEFORM:        31
  SUN_POSTN:        32.51d {+02h 10m 02s}  +13.11d {+13d 06' 53"}
  SUN_DIST:         93.09 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
  MOON_POSTN:      239.05d {+15h 56m 12s}  -15.48d {-15d 28' 45"}
  MOON_DIST:        72.02 [deg]
  MOON_ILLUM:      95 [%]
  GAL_COORDS:      334.71,-41.20 [deg] galactic lon,lat of the burst
  ECL_COORDS:      300.38,-42.09 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Coordinates.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
  COMMENTS:        TAM values, flux and significance fields are not valid.  
  COMMENTS:        This position was automatically generated on the ground using  
  COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
  COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
  COMMENTS:        The probability that this is a serendipitous source in the  
  COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.  
  

• GCN Circular #19336
  P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), M. Perri (ASDC) and G. Tagliaferri (INAF-OAB) report on behalf of the Swift-XRT team:
  The XRT began observing the field of GRB 160424A at 12:40:02.1 UT, 3054.8 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 319.48505, -60.41481 which is equivalent to:

     RA(J2000)  = 21h 17m 56.41s
     Dec(J2000) = -60d 24' 53.3"
  

  with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 36 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 (3.94 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.5 (+2.04/-1.82) x 10^21 cm^-2 (90% confidence).
• GCN Circular #19337
  F.E. Marshall (NASA/GSFC) and A. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team:
  UVOT took a finding chart exposure of 150 seconds with the White filter starting 3059 seconds after the BAT trigger (Lien et al. GCN Circ. 19335). 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 region (Evans et al. GCN Circ 19336). Sensitivity is less than usual because of reduced pointing stability. We estimate an upper limit of 16th mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03.
• GCN Circular #19338
  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-61 to T+243 sec from the recent telemetry downlinks, we report further analysis of BAT GRB 160424A (trigger #683906) (Lien, et al., GCN Circ. 19335). The BAT ground-calculated position is RA, Dec = 319.482, -60.408 deg, which is

     RA(J2000)  =  21h 17m 55.7s 
     Dec(J2000) = -60d 24' 29.8" 
  

  with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 33%.
  The mask-weighted light curve shows a FRED-like peak starting at ~T-0.5 sec, peaking at ~T+0.4 sec, and ending at ~T+10 sec. T90 (15-350 keV) is 6.3 +- 1.0 sec (estimated error including systematics).
  The time-averaged spectrum from T-1.51 to T+6.63 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.40 +- 0.10. 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+0.06 sec in the 15-150 keV band is 5.1 +- 0.4 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/683906/BA/
• GCN Circular #19339
  P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
  During the XRT observations of GRB 160424A (Evans et al., GCN Circ. 19336) the star trackers onboard Swift were unable to acquire a correct lock. As a result of this the attitude solution for the spacecraft is uncertain, and visual inspection of the images shows that the position of the XRT afterglow is highly uncertain. Our best estimate of the position is as given in GCN Circ. 19336, however the uncertainty is ~50 arc sec.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #19340
  Hoi-Fung Yu (MPE) reports on behalf of the Fermi GBM Team:
  "At 11:49:06.48 UT on 24 April 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160424A (trigger 483191350 / 160424492), which was also detected by the Swift (Lien et al. 2016, GCN 19335) The GBM on-ground location is consistent with the Swift position.
  The angle from the Fermi LAT boresight at the GBM trigger time is 18 degrees.
  This burst was also independently detected by INTEGRAL SPI-ACS.
  The GBM light curve shows a single pulse with a duration (T90) of about 7.6 s (50-300 keV). The time-averaged spectrum from T0+0.003 s to T0+6.528 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.1 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 220 +/- 30 keV.
  The event fluence (10-1000 keV) in this time interval is (2.6 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+0.832 s in the 10-1000 keV band is 7.2 +/- 0.3 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #19342
  A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration GRB 160424A (Swift-BAT trigger #683906: Lien et al., GCN Circ. 19335; Krimm et al., GCN Circ. 19338; Fermi GBM detection: Hoi-Fung Yu, GCN Circ. 19340) triggered Konus-Wind at T0=42546.397 s UT (11:49:06.397).
  The burst light curve shows a single pulse with a total duration of ~2.3 s. The emission is seen up to 2 MeV.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB160424_T42546/
  As observed by Konus-Wind, the burst had a fluence of 1.59(-0.35,+0.60)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.464 s, of 1.71(-0.62,+0.84)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-integrated spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.24(-0.51,+0.66) and Ep = 133(-40,+134) keV (chi2 = 58/60 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 = 57/59 dof)
  All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.