Gamma-ray Burst 130408A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 21:57:54 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     553132,   Seg_Num: 0
  GRB_RA:          134.401d {+08h 57m 36s} (J2000),
                   134.538d {+08h 58m 09s} (current),
                   133.887d {+08h 55m 33s} (1950)
  GRB_DEC:         -32.361d {-32d 21' 37"} (J2000),
                   -32.412d {-32d 24' 43"} (current),
                   -32.167d {-32d 10' 00"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       17050 [cnts]    Image_Peak=187 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   488     E_range: 50-350 keV
  BKG_INTEN:       94875 [cnts]
  BKG_TIME:        78645.58 SOD {21:50:45.58} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        16390 TJD;    98 DOY;   13/04/08
  GRB_TIME:        78698.82 SOD {21:51:38.82} UT
  GRB_PHI:         -173.44 [deg]
  GRB_THETA:        58.32 [deg]
  SOLN_STATUS:     0x20000003
  RATE_SIGNIF:     69.57 [sigma]
  IMAGE_SIGNIF:    7.51 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +3  -2  +0  +1 +44  +0 
  SUN_POSTN:        17.74d {+01h 10m 58s}   +7.52d {+07d 31' 30"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.87d {+23h 59m 28s}   +3.93d {+03d 55' 33"}
  MOON_DIST:       128.96 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.21,  8.58 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      150.03,-46.98 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
  COMMENTS:        probably due to it occurring during a Malindi downlink session.  
  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 = 11.78,-4.41 [deg].  
  COMMENTS:           
  COMMENTS:        NOTE: This BAT event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=6818).  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 21:58:25 UT
  NOTICE_TYPE:     Swift-XRT Nack-Position
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.392d {+08h 57m 34s} (J2000)
  POINT_DEC:       -32.352d {-32d 21' 08"} (J2000)
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  78848.69 SOD {21:54:08.69} UT,   149.9 [sec] since BAT Trigger Time
  COUNTS:          6    Min_needed= 20
  STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
  PH2_ITER:        1    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:     Mon 08 Apr 13 21:59:19 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     553132,   Seg_Num: 0
  GRB_RA:          134.401d {+08h 57m 36s} (J2000),
                   134.538d {+08h 58m 09s} (current),
                   133.887d {+08h 55m 33s} (1950)
  GRB_DEC:         -32.361d {-32d 21' 37"} (J2000),
                   -32.412d {-32d 24' 43"} (current),
                   -32.167d {-32d 10' 00"} (1950)
  GRB_DATE:        16390 TJD;    98 DOY;   13/04/08
  GRB_TIME:        78698.82 SOD {21:51:38.82} UT
  TRIGGER_INDEX:   488
  GRB_PHI:         -173.44 [deg]
  GRB_THETA:        58.32 [deg]
  DELTA_TIME:      -44.00 [sec]
  TRIGGER_DUR:     4.096 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     69.57 [sigma]
  IMAGE_SIGNIF:    7.51 [sigma]
  LC_URL:          sw00553132000msb.lc
  SUN_POSTN:        17.74d {+01h 10m 58s}   +7.53d {+07d 31' 31"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.88d {+23h 59m 31s}   +3.93d {+03d 55' 48"}
  MOON_DIST:       128.96 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.21,  8.58 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      150.03,-46.98 [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 = 11.78,-4.41 [deg].  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 22:00:15 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.392d {+08h 57m 34s} (J2000)
  POINT_DEC:       -32.352d {-32d 21' 08"} (J2000)
  POINT_ROLL:      261.813d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  78853.60 SOD {21:54:13.60} UT,   154.8 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        2.169
  N_STARS:         190
  X_OFFSET:        410 [pixels]
  Y_OFFSET:        498 [pixels]
  X_MAX:           1369 [pixels]
  Y_MAX:           1457 [pixels]
  DET_THRESH:      12
  PHOTO_THRESH:    6
  SL_URL:          sw00553132000msufc0154.fits
  SUN_POSTN:        17.74d {+01h 10m 59s}   +7.53d {+07d 31' 32"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.89d {+23h 59m 33s}   +3.93d {+03d 55' 58"}
  MOON_DIST:       128.95 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.98 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 22:00:38 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.392d {+08h 57m 34s} (J2000)
  POINT_DEC:       -32.352d {-32d 21' 08"} (J2000)
  POINT_ROLL:      261.813d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  78853.60 SOD {21:54:13.60} UT,   154.8 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        2.169
  N_STARS:         190
  X_OFFSET:        410 [pixels]
  Y_OFFSET:        498 [pixels]
  X_MAX:           1369 [pixels]
  Y_MAX:           1457 [pixels]
  DET_THRESH:      12
  PHOTO_THRESH:    6
  SL_URL:          sw00553132000msufc0154.fits
  SUN_POSTN:        17.74d {+01h 10m 59s}   +7.53d {+07d 31' 32"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.89d {+23h 59m 34s}   +3.93d {+03d 56' 03"}
  MOON_DIST:       128.95 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.98 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Source List.  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 22:01:37 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.392d {+08h 57m 34s} (J2000)
  POINT_DEC:       -32.352d {-32d 21' 08"} (J2000)
  ROLL:            261.813d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  78853.60 SOD {21:54:13.60} UT,   154.8 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     387150864
  X_OFFSET:        729 [pixels]
  Y_OFFSET:        817 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       889
  Y_GRB_POS:       977
  BINNING_INDEX:   1
  IM_URL:          sw00553132000msuni0165.fits
  SUN_POSTN:        17.74d {+01h 10m 59s}   +7.53d {+07d 31' 33"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.90d {+23h 59m 36s}   +3.94d {+03d 56' 13"}
  MOON_DIST:       128.94 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.98 [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:     Mon 08 Apr 13 22:01:53 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.392d {+08h 57m 34s} (J2000)
  POINT_DEC:       -32.352d {-32d 21' 08"} (J2000)
  ROLL:            261.813d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  78853.60 SOD {21:54:13.60} UT,   154.8 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     387150864
  X_OFFSET:        729 [pixels]
  Y_OFFSET:        817 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       889
  Y_GRB_POS:       977
  BINNING_INDEX:   1
  IM_URL:          sw00553132000msuni0165.fits
  SUN_POSTN:        17.74d {+01h 10m 59s}   +7.53d {+07d 31' 34"}
  SUN_DIST:        116.57 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.90d {+23h 59m 36s}   +3.94d {+03d 56' 16"}
  MOON_DIST:       128.94 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.98 [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:        All 4 attachments are included.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 22:02:25 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.394d {+08h 57m 35s} (J2000)
  POINT_DEC:       -32.350d {-32d 21' 00"} (J2000)
  POINT_ROLL:      261.815d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  79011.87 SOD {21:56:51.87} UT,   313.0 [sec] since BAT Trigger Time
  FILTER:          7, U
  BKG_MEAN:        0.115
  N_STARS:         190
  X_OFFSET:        170 [pixels]
  Y_OFFSET:        258 [pixels]
  X_MAX:           1609 [pixels]
  Y_MAX:           1697 [pixels]
  DET_THRESH:      4
  PHOTO_THRESH:    2
  SL_URL:          sw00553132000msufc0313.fits
  SUN_POSTN:        17.75d {+01h 10m 59s}   +7.53d {+07d 31' 34"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.91d {+23h 59m 37s}   +3.94d {+03d 56' 22"}
  MOON_DIST:       128.94 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.97 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 22:02:42 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.394d {+08h 57m 35s} (J2000)
  POINT_DEC:       -32.350d {-32d 21' 00"} (J2000)
  POINT_ROLL:      261.815d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  79011.87 SOD {21:56:51.87} UT,   313.0 [sec] since BAT Trigger Time
  FILTER:          7, U
  BKG_MEAN:        0.115
  N_STARS:         190
  X_OFFSET:        170 [pixels]
  Y_OFFSET:        258 [pixels]
  X_MAX:           1609 [pixels]
  Y_MAX:           1697 [pixels]
  DET_THRESH:      4
  PHOTO_THRESH:    2
  SL_URL:          sw00553132000msufc0313.fits
  SUN_POSTN:        17.75d {+01h 10m 59s}   +7.53d {+07d 31' 34"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.91d {+23h 59m 38s}   +3.94d {+03d 56' 25"}
  MOON_DIST:       128.94 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.97 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Source List.  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Mon 08 Apr 13 22:03:09 UT
  NOTICE_TYPE:     Swift-XRT Position
  TRIGGER_NUM:     553132,   Seg_Num: 0
  GRB_RA:          134.4080d {+08h 57m 37.91s} (J2000),
                   134.5446d {+08h 58m 10.69s} (current),
                   133.8936d {+08h 55m 34.46s} (1950)
  GRB_DEC:         -32.3613d {-32d 21' 40.6"} (J2000),
                   -32.4131d {-32d 24' 47.0"} (current),
                   -32.1674d {-32d 10' 02.5"} (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:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  78863.00 SOD {21:54:23.00} UT,   164.2 [sec] since BAT Trigger Time
  TAM[0-3]:        100.00 100.00 100.00 100.00
  AMPLIFIER:       1
  WAVEFORM:        31
  SUN_POSTN:        17.75d {+01h 10m 59s}   +7.53d {+07d 31' 35"}
  SUN_DIST:        116.59 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.91d {+23h 59m 39s}   +3.94d {+03d 56' 30"}
  MOON_DIST:       128.94 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.21,  8.58 [deg] galactic lon,lat of the burst
  ECL_COORDS:      150.04,-46.98 [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:     Mon 08 Apr 13 22:03:42 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.394d {+08h 57m 35s} (J2000)
  POINT_DEC:       -32.350d {-32d 21' 00"} (J2000)
  ROLL:            261.815d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  79011.87 SOD {21:56:51.87} UT,   313.0 [sec] since BAT Trigger Time
  FILTER:          7, U
  EXPOSURE_ID:     387151022
  X_OFFSET:        729 [pixels]
  Y_OFFSET:        817 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       889
  Y_GRB_POS:       977
  BINNING_INDEX:   1
  IM_URL:          sw00553132000msuni0324.fits
  SUN_POSTN:        17.75d {+01h 10m 59s}   +7.53d {+07d 31' 35"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.92d {+23h 59m 40s}   +3.94d {+03d 56' 36"}
  MOON_DIST:       128.93 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.97 [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:     Mon 08 Apr 13 22:03:56 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     553132,   Seg_Num: 0
  POINT_RA:        134.394d {+08h 57m 35s} (J2000)
  POINT_DEC:       -32.350d {-32d 21' 00"} (J2000)
  ROLL:            261.815d
  IMG_START_DATE:  16390 TJD;    98 DOY;   13/04/08
  IMG_START_TIME:  79011.87 SOD {21:56:51.87} UT,   313.0 [sec] since BAT Trigger Time
  FILTER:          7, U
  EXPOSURE_ID:     387151022
  X_OFFSET:        729 [pixels]
  Y_OFFSET:        817 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       889
  Y_GRB_POS:       977
  BINNING_INDEX:   1
  IM_URL:          sw00553132000msuni0324.fits
  SUN_POSTN:        17.75d {+01h 10m 59s}   +7.53d {+07d 31' 36"}
  SUN_DIST:        116.58 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
  MOON_POSTN:      359.92d {+23h 59m 41s}   +3.94d {+03d 56' 39"}
  MOON_DIST:       128.93 [deg]
  MOON_ILLUM:      2 [%]
  GAL_COORDS:      256.20,  8.58 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      150.02,-46.97 [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:        All 4 attachments are included.  
  

  
• GCN Circular #14361
  A. Y. Lien (NASA/GSFC/ORAU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), D. Malesani (DARK/NBI), V. Mangano (INAF-IASFPA), C. Pagani (U Leicester), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team:
  At 21:51:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130408A (trigger=553132). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 134.401, -32.361 which is

     RA(J2000) = 08h 57m 36s
     Dec(J2000) = -32d 21' 37"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 12 sec. The peak count rate was ~3914 counts/sec (15-350 keV), at ~1 sec after the trigger.
  The XRT began observing the field at 21:54:08.6 UT, 149.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 134.40809, -32.36136 which is equivalent to:

     RA(J2000)  = 08h 57m 37.94s
     Dec(J2000) = -32d 21' 40.9"
  

  with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 21 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. We cannot determine whether the source is fading at the present time.
  A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.98 x 10^21 cm^-2 (Kalberla et al. 2005).
  UVOT data analysis is not available at this time.
  Burst Advocate for this burst is A. Y. Lien (yarleen 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.)
• GCN Circular #14362
  A. Melandri (INAF-OAB), J. Japelj (U. Ljubljana), F.J. Virgili(LJMU), C.G. Mundell (LJMU) report:
  The 2-m Liverpool Telescope robotically followed up GRB130408A (Swift trigger 553132, Lien et al., GCN 14361) 19.42 min after the GRB trigger time observing with SLOAN-gri filters.
  The automatic LT-TRAP procedure detected an uncatalogued fading source candidate at:

  RA=08:57:37.30
  Dec=-32:21:38.90    (J2000)
  

  with magnitude R~16.5 mag (vs USNOB1) ~20 min after the burst trigger. The object is clearly fading in all filters and we suggest this is the optical afterglow of GRB130408A.
  Observations and analysis are ongoing.
• GCN Circular #14363
  M. H. Siegel (PSU) and A. Y. Lien (NASA/GSFC/ORAU) report on behalf of the UVOT team:
  UVOT took a finding chart exposure of 150 seconds with the White filter starting 155 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at

   RA(J2000)  =	08:57:37.30 = 134.40540
   DEC(J2000) = -32:21:38.9  = -32.36081
  

  with a 90%-confidence error radius of about 0.5 arc sec. This position is 8.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.82 with a 1-sigma error of about 0.04. No correction has been made for the expected extinction corresponding to E(B-V) of 0.26.
• GCN Circular #14364
  V. Sudilovsky (MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg) and J. Greiner (MPE Garching) report on behalf of the GROND team:
  We observed the field of GRB 130408A (Swift trigger 553132; Lien et al., GCN 14361) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
  Observations started at 23:22 UT on April 8th, 1.5 hrs after the GRB trigger. They were performed at an average seeing of 1.0 and at an average airmass of 1.0.
  Based integrations of 260s in the optical and 240s in the NIR taken at a mid-time of UT 23:34, we detect the variable source reported by Melandri et al. (GCN 14362) and Siegel & Lien (GCN 14363), with preliminary magnitudes (all AB):

  g' = 21.0 +- 0.1,
  r' = 19.7 +- 0.1,
  i' = 19.1 +- 0.1,
  z' = 18.8 +- 0.1,
  J  = 18.0 +- 0.1,
  H  = 17.8 +- 0.1, and
  K  > 17.0.
  

  The large r-g color implies a redshift of z>3. Observations are ongoing.
  Given magnitudes are calibrated against GROND zeropoints in g'r'i'z' and 2MASS field stars in JHK. They are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.26 mag in the direction of the burst (Schlegel et al. 1998).
• GCN Circular #14365
  J. Hjorth (DARK), A. Melandri (INAF-OAB), D. Malesani (DARK), T. Kruehler (DARK), and D. Xu (DARK) report on behalf of a larger collaboration:
  We observed the afterglow of GRB 130408A (Lien et al. GCN 14361; Melandri et al. GCN 14362; Siegel et al. GCN 14363) with the X-shooter spectrograph on the ESO VLT, beginning approximately 1 h 55 min after the BAT trigger.
  We detect damped Ly-alpha absorption, Ly-alpha forest, the Lyman break, and numerous metal lines consistent with a redshift of 3.758.
  We thank Maria Teresa Ruiz, Avril Day-Jones, Cedric Ledoux, Leo Rivas, Alex Correa, and Lorenzo Monaco for conducting the observations.
• GCN Circular #14366
  N. R. Tanvir (U. Leicester), A. Cucchiara (UCSC/UCO Lick Observatory) and S. B. Cenko (UC Berkeley) report on behalf of a larger collaboration:
  We observed the afterglow of GRB 130408A (Lien et al. GCN 14361, Melandri et al. GCN 14362, Siegel et al. GCN 14363) with the GMOS-S spectrograph on Gemini-S, beginning approximately 1 hr 56 mins after the BAT trigger. The integration was 4x600s and the wavelength covered approximately 3950-6700A.
  We detect numerous lines, including Lyman alpha, beta, gamma, SII1250, SII1253, CII/CII*1260, SiII*1264, OI1302, SiII/OI*1304, SiII*1309, CII/CII* 1334/1335, SiIV1394/1402 at a common redshift of z=3.757.
  We thank D. Krogsrud for performing the observation.
• GCN Circular #14367
  A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
  Using 573 s of XRT Photon Counting mode data and 3 UVOT images for GRB 130408A, 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 = 134.40543, -32.36089 which is equivalent to:

  RA (J2000): 08h 57m 37.30s
  Dec (J2000): -32d 21' 39.2"
  

  with an uncertainty of 1.7 arcsec (radius, 90% confidence).
  This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
  This circular was automatically generated, and is an official product of the Swift-XRT team.
• GCN Circular #14368
  S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration GRB 130408A (Swift/BAT trigger=3D553132: Lien et al., GCN 14361) triggered Konus-Wind at T0=3D78701.184s UT (21:51:41.194)
  The light curve shows a bright pulse from ~T0-0.5 to ~T0+5 s followed by a much weaker emission pulse peaked around ~T0+12; a total duration of the burst is ~15 s. The emission is seen up to several MeV.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130408_T78701/
  As observed by Konus-Wind, the burst had a fluence of (1.2 =B1 0.2)x10-5 erg/cm2, and a 64-ms peak flux, measured from T0+3.328s, of (5.2 =B1 0.5)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-integrated spectrum (measured from T0 to T0+16.640 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha =3D -0.4 =B1 0.2, the high energy photon index beta =3D -2.3 =B1 0.2, the peak energy Ep =3D 211 =B1 29 keV, chi2 =3D 99.4/97 dof.
  The spectrum at the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha =3D -0.70 =B1 0.15, the high energy photon index beta =3D -2.3 =B1 0.3, the peak energy Ep =3D 272 =B1 40 keV, chi2 =3D 87.7/99 dof.
  Assuming redshift z=3D3.758 (Hjorth et al., GCN 14365; Tanvir et al., GCN= 14366), and a standard cosmology (H_0=3D70 km/s/Mpc, Omega_M=3D0.3, Omega_\Lambda= =3D0.7), we estimate the following cosmological rest-frame parameters of the promp= t gamma-ray emission: - the isotropic equivalent energy release E_iso =3D (3.3 =B1 0.6)x10^53 e= rg; - the peak luminosity L_iso =3D (5.5 =B1 0.5)x10^53 erg/s; - the peak energy of the time-integrated spectrum Ep_rest =3D 1.00 =B1 0.= 14 MeV.
  All the quoted results are preliminary.
• GCN Circular #14369
  V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), V. Mangano (INAF-IASFPA), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester) and A.Y. Lien report on behalf of the Swift-XRT team:
  We have analysed 6.2 ks of XRT data for GRB 130408A (Lien et al. GCN Circ. 14361), from 134 s to 28.6 ks after the BAT trigger. The data comprise 28 s in Windowed Timing (WT) mode (the first 9 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 Beardmore et al. (GCN. Circ 14367).
  The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.39 (+0.06, -0.07). At T+3999 s the decay steepens to an alpha of 8.0 (+0.0, -3.0) before breaking again at T+4518 s to a final decay with index alpha=0.97 (+0.14, -0.15).
  A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.00 (+0.08, -0.07). The best-fitting absorption column is consistent with the Galactic value of 2.0 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (5.6 x 10^-11) erg cm^-2 count^-1.
  A summary of the PC-mode spectrum is thus:

  Galactic foreground: 2.0 x 10^21 cm^-2
  Intrinsic column:    0 (+4.9, -0) x 10^21 cm^-2 at z=3.758
  Photon index:	     2.00 (+0.08, -0.07)
  

  If the light curve continues to decay with a power-law decay index of 0.97, the count rate at T+24 hours will be 0.020 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.8 x 10^-13 (1.1 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/00553132.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #14370
  A. Breeveld (MSSL/UCL) and A. Y. Lien (NASA/GSFC/ORAU) report on behalf=20 of the Swift/UVOT team:
  The Swift/UVOT began settled observations of the field of GRB 130408A=20 134 s after the BAT trigger (Lien et al., GCN Circ. 14361). A bright but=20 rapidly fading source is detected in the initial exposures (Siegel and=20 Lien, GCN Circ. 14363) with a position consistent with detections by=20 Melandri et al., (GCN Circ., 14362), Sudilovsky et al., (GCN Circ.,=20 14364) and Beardmore et al., (GCN Circ. 14367).
  The preliminary UVOT position is:

    RA(J2000)  =3D    08:57:37.30 =3D 134.40540
    DEC(J2000) =3D   -32:21:38.9  =3D -32.36081
  

  with a 90%-confidence error radius of about 0.5 arc sec.
  Preliminary detections and 3-sigma upper limits using the UVOT=20 photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for=20 the early and summed exposures are:

  Filter         T_start(s)   T_stop(s)      Exp(s)           Mag
  
  white              156          305      147.4          16.80 =B1 0.05
  white             3708         3900      189.2          20.29 =B1 0.22
  white             6083        10367      924.3          21.99 =B1 0.35
  v                  134          145       10.1          15.75 =B1 0.15
  v                 4201         4400      196.7          19.61 =B1 0.35
  b                 3503         6078      393.2          >20.84
  u                  313         5872      236.2          >20.55
  uvw1              4611         4752      139.0          >19.82
  uvm2              4405         4605      196.6          >19.75
  uvw2              3996        21851     1748.0          >21.56
  

  The magnitudes in the table are not corrected for the Galactic=20 extinction due to the reddening of E(B-V) =3D 0.258 in the direction of=20 the burst (Schlegel et al. 1998).
• GCN Circular #14372
  H. Dereli (UNS-CNRS-OCA), A. Klotz (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), B. Gendre (IRAP-CNRS-OMP), M. Boer, K. Siellez, O. Bardho (UNS-CNRS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA)
  We imaged the field of GRB 1130408A detected by SWIFT (trigger 553132) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia.
  The observations started 13.99h after the GRB trigger. The elevation of the field increased from 87.5 degrees above horizon and weather conditions were good.
  The co addition of the six images filtered C, g, r gives one image with an equivalent exposure time of 540s. We did not detected the afteglow mentioned in Melandri et al. (GCNC 14362):
  t0+13.99h to t0+14.56h : Rlim = 20.5
  The limiting magnitude of the zadko image is R~20.5.
  Magnitudes were estimated with the nearby NOMAD1 stars and are not corrected for galactic dust extinction.
• GCN Circular #14373
  W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
  Using the data set from T-240 to T+960 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130408A (trigger #553132) (Lien, et al., GCN Circ. 14361). The BAT ground-calculated position is RA, Dec = 134.398, -32.363 deg which is

      RA(J2000)  =  08h 57m 35.5s
      Dec(J2000) = -32d 21' 45.9"
  

  with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 6%.
  T90 (15-350 keV) is 28 +- 13 sec (estimated error including systematics). The mask weighted light curve has a main FRED-like component with a rise time of about 2 sec and decline of 5 sec, peaking at time T+1 sec, followed by a smaller peak at T+12 sec. There is possible low-level emission out to about T+33 sec.
  The time-averaged spectrum from T-0.1 to T+33.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.28 +- 0.26. The fluence in the 15-150 keV band is 2.3 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.12 sec in the 15-150 keV band is 4.9 +- 1.0 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/553132/BA/
• GCN Circular #14374
  B. E. Cobb (GWU), reports:
  Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 130408A (GCN 14361, Lien et al.) over several epochs (with mid-exposure times of 2013-04-09 00:30 UT, 02:15 UT, 03:41 UT and 2013-04-11 02:24 UT). For each epoch, several dithered images were obtained with total summed exposure times of 15 min in V and I and 12 min in J and K. For the final epoch, total exposure times were 36 min in I and 30 min in J.
  The fading afterglow of GRB 130408A (e.g. GCN 14362, Melandri et al.; GCN 14363, Siegel et al.; GCN 14364, Sudilovsky et al.) was detected with the following magnitudes (or 3-sigma limits):

  mid-exposure
  time
  (hours)           I mag             J mag            K mag
  2.64611         18.8 +/- 0.1    17.8 +/- 0.1     > 16.1
  4.38444         19.6 +/- 0.1    18.6 +/- 0.2    16.8 +/- 0.2
  5.82472         20.0 +/- 0.1    18.6 +/- 0.2     > 17.2
  52.53694        > 21.5            > 19.6            ...
  

  (Optical photometry is calibrated against USNO-B1.0 stars and IR photometry is calibrated against 2MASS stars in the field.)
  Between about 2.6 hrs and 5.8 hrs post-burst, the GRB afterglow fades with a decay rate of approximately alpha = 1.4 (where afterglow flux is proportional to t^-alpha).
• GCN Circular #14375
  A. Trotter, N. Frank, A. LaCluyze, D. Reichart, J. Haislip, K. Ivarsen, J. Moore, H. T. Cromartie, R. Egger, A. Foster, M. Nysewander, A. Oza, E. Speckhard, and J. A. Crain report:
  Skynet began observing the field of GRB130408A (Swift trigger 553132, GCN 14361) in BVRI beginning ~93 minutes after the burst using four of the PROMPT telescopes located at CTIO in Chile. A fading source is detected at the enhanced position reported by the Swift-XRT team (GCN 14367.)
  A preliminary light curve of the first two night's data from PROMPT can be found at: http://skynet.unc.edu/grb/grb130408a.png
  
• GCN Circular #14376
  K. Takaki, M. Ohno, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa (Hiroshima U.), M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, H. Ueno, S. Sugimoto(Saitama U.), K. Yamaoka (Nagoya U.), M. Yamauchi, M. Akiyama, N. Ohmori (Univ. of Miyazaki), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report:
  The long GRB 130408A (Lien et al., GCN14361) triggered by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 21:51:38 UT (=T0).
  The observed light curve shows a single peak starting at T0-2s, ending at T0+5s with a duration (T90) of about 7 seconds. The fluence in 100 - 1000 keV was 7.18(+0.06/-0.15) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0s was 5.42(+1.37/-2.27) photons/cm^2/s in the same energy range.
  Preliminary result shows that the time-averaged spectrum from T0-2s to T0+5s is well fitted by a single power-law with a photon index of 2.32 (+0.41/-0.34) (chi2/d.o.f = 12.19/13).
  All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included.
  The light curves for this burst will be available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
• GCN Report 439.1
  GCN_Report 439.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_439_1.pdf by A.Y. Lien at NASA/GSFC/ORAU titled: "Swift Observations of GRB 130408A"