Gamma-ray Burst 170604A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 04 Jun 17 19:09:34 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     755867,   Seg_Num: 0
  GRB_RA:          342.645d {+22h 50m 35s} (J2000),
                   342.876d {+22h 51m 30s} (current),
                   341.981d {+22h 47m 55s} (1950)
  GRB_DEC:         -15.414d {-15d 24' 50"} (J2000),
                   -15.322d {-15d 19' 17"} (current),
                   -15.680d {-15d 40' 45"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       13046 [cnts]    Image_Peak=219 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   307     E_range: 50-350 keV
  BKG_INTEN:       93792 [cnts]
  BKG_TIME:        68876.83 SOD {19:07:56.83} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        17908 TJD;   155 DOY;   17/06/04
  GRB_TIME:        68930.40 SOD {19:08:50.40} UT
  GRB_PHI:         165.47 [deg]
  GRB_THETA:        52.39 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     30.62 [sigma]
  IMAGE_SIGNIF:    7.97 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +3  -2  +0  +0 +10  +0 
  SUN_POSTN:        73.02d {+04h 52m 05s}  +22.52d {+22d 31' 07"}
  SUN_DIST:         95.94 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      201.96d {+13h 27m 52s}   -4.79d {-04d 47' 05"}
  MOON_DIST:       136.38 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.39,-59.61 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      338.12, -7.44 [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 = 224.74,-1.67 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 04 Jun 17 19:11:01 UT
  NOTICE_TYPE:     Swift-XRT Nack-Position
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.402d {-15d 24' 08"} (J2000)
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69055.12 SOD {19:10:55.12} UT,   124.7 [sec] since BAT Trigger Time
  COUNTS:          8    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:     Sun 04 Jun 17 19:12:41 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     755867,   Seg_Num: 0
  GRB_RA:          342.645d {+22h 50m 35s} (J2000),
                   342.876d {+22h 51m 30s} (current),
                   341.981d {+22h 47m 55s} (1950)
  GRB_DEC:         -15.414d {-15d 24' 50"} (J2000),
                   -15.322d {-15d 19' 17"} (current),
                   -15.680d {-15d 40' 45"} (1950)
  GRB_DATE:        17908 TJD;   155 DOY;   17/06/04
  GRB_TIME:        68930.40 SOD {19:08:50.40} UT
  TRIGGER_INDEX:   307
  GRB_PHI:         165.47 [deg]
  GRB_THETA:        52.39 [deg]
  DELTA_TIME:      -76.00 [sec]
  TRIGGER_DUR:     4.096 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     30.62 [sigma]
  IMAGE_SIGNIF:    7.97 [sigma]
  LC_URL:          sw00755867000msb.lc
  SUN_POSTN:        73.02d {+04h 52m 06s}  +22.52d {+22d 31' 08"}
  SUN_DIST:         95.94 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      201.99d {+13h 27m 57s}   -4.79d {-04d 47' 35"}
  MOON_DIST:       136.35 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.39,-59.61 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      338.12, -7.44 [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 = 224.74,-1.67 [deg].  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 04 Jun 17 19:15:20 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.402d {-15d 24' 07"} (J2000)
  POINT_ROLL:      68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69058.34 SOD {19:10:58.34} UT,   127.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        6.402
  N_STARS:         10
  X_OFFSET:        458 [pixels]
  Y_OFFSET:        621 [pixels]
  X_MAX:           1417 [pixels]
  Y_MAX:           1580 [pixels]
  DET_THRESH:      22
  PHOTO_THRESH:    13
  SL_URL:          sw00755867000msufc0127.fits
  SUN_POSTN:        73.03d {+04h 52m 06s}  +22.52d {+22d 31' 09"}
  SUN_DIST:         95.93 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.01d {+13h 28m 03s}   -4.80d {-04d 48' 01"}
  MOON_DIST:       136.34 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.13, -7.43 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 04 Jun 17 19:15:33 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.402d {-15d 24' 07"} (J2000)
  POINT_ROLL:      68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69058.34 SOD {19:10:58.34} UT,   127.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        6.402
  N_STARS:         10
  X_OFFSET:        458 [pixels]
  Y_OFFSET:        621 [pixels]
  X_MAX:           1417 [pixels]
  Y_MAX:           1580 [pixels]
  DET_THRESH:      22
  PHOTO_THRESH:    13
  SL_URL:          sw00755867000msufc0127.fits
  SUN_POSTN:        73.03d {+04h 52m 06s}  +22.52d {+22d 31' 09"}
  SUN_DIST:         95.93 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.01d {+13h 28m 03s}   -4.80d {-04d 48' 03"}
  MOON_DIST:       136.34 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.13, -7.43 [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 04 Jun 17 19:16:49 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.402d {-15d 24' 07"} (J2000)
  ROLL:            68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69058.34 SOD {19:10:58.34} UT,   127.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     518296277
  X_OFFSET:        777 [pixels]
  Y_OFFSET:        940 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       937
  Y_GRB_POS:       1100
  BINNING_INDEX:   1
  IM_URL:          sw00755867000msuni0147.fits
  SUN_POSTN:        73.03d {+04h 52m 06s}  +22.52d {+22d 31' 09"}
  SUN_DIST:         95.93 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.02d {+13h 28m 05s}   -4.80d {-04d 48' 15"}
  MOON_DIST:       136.33 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.13, -7.43 [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 04 Jun 17 19:17:02 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.402d {-15d 24' 07"} (J2000)
  ROLL:            68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69058.34 SOD {19:10:58.34} UT,   127.9 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     518296277
  X_OFFSET:        777 [pixels]
  Y_OFFSET:        940 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       937
  Y_GRB_POS:       1100
  BINNING_INDEX:   1
  IM_URL:          sw00755867000msuni0147.fits
  SUN_POSTN:        73.03d {+04h 52m 06s}  +22.52d {+22d 31' 09"}
  SUN_DIST:         95.93 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.02d {+13h 28m 06s}   -4.81d {-04d 48' 18"}
  MOON_DIST:       136.33 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.13, -7.43 [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 04 Jun 17 19:36:22 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.406d {-15d 24' 19"} (J2000)
  POINT_ROLL:      68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69216.68 SOD {19:13:36.68} UT,   286.3 [sec] since BAT Trigger Time
  FILTER:          7, U
  BKG_MEAN:        1.766
  N_STARS:         27
  X_OFFSET:        218 [pixels]
  Y_OFFSET:        381 [pixels]
  X_MAX:           1657 [pixels]
  Y_MAX:           1820 [pixels]
  DET_THRESH:      11
  PHOTO_THRESH:    5
  SL_URL:          sw00755867000msufc0286.fits
  SUN_POSTN:        73.04d {+04h 52m 10s}  +22.52d {+22d 31' 15"}
  SUN_DIST:         95.95 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.18d {+13h 28m 43s}   -4.86d {-04d 51' 25"}
  MOON_DIST:       136.17 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.12, -7.43 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 04 Jun 17 19:36:29 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.406d {-15d 24' 19"} (J2000)
  POINT_ROLL:      68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69216.68 SOD {19:13:36.68} UT,   286.3 [sec] since BAT Trigger Time
  FILTER:          7, U
  BKG_MEAN:        1.766
  N_STARS:         27
  X_OFFSET:        218 [pixels]
  Y_OFFSET:        381 [pixels]
  X_MAX:           1657 [pixels]
  Y_MAX:           1820 [pixels]
  DET_THRESH:      11
  PHOTO_THRESH:    5
  SL_URL:          sw00755867000msufc0286.fits
  SUN_POSTN:        73.04d {+04h 52m 10s}  +22.52d {+22d 31' 15"}
  SUN_DIST:         95.95 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.18d {+13h 28m 43s}   -4.86d {-04d 51' 26"}
  MOON_DIST:       136.16 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.12, -7.43 [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 04 Jun 17 19:37:43 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.406d {-15d 24' 19"} (J2000)
  ROLL:            68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69216.68 SOD {19:13:36.68} UT,   286.3 [sec] since BAT Trigger Time
  FILTER:          7, U
  EXPOSURE_ID:     518296435
  X_OFFSET:        777 [pixels]
  Y_OFFSET:        940 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       937
  Y_GRB_POS:       1100
  BINNING_INDEX:   1
  IM_URL:          sw00755867000msuni0306.fits
  SUN_POSTN:        73.04d {+04h 52m 10s}  +22.52d {+22d 31' 15"}
  SUN_DIST:         95.95 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.19d {+13h 28m 45s}   -4.86d {-04d 51' 38"}
  MOON_DIST:       136.15 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.12, -7.43 [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 04 Jun 17 19:37:57 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     755867,   Seg_Num: 0
  POINT_RA:        342.649d {+22h 50m 36s} (J2000)
  POINT_DEC:       -15.406d {-15d 24' 19"} (J2000)
  ROLL:            68.281d
  IMG_START_DATE:  17908 TJD;   155 DOY;   17/06/04
  IMG_START_TIME:  69216.68 SOD {19:13:36.68} UT,   286.3 [sec] since BAT Trigger Time
  FILTER:          7, U
  EXPOSURE_ID:     518296435
  X_OFFSET:        777 [pixels]
  Y_OFFSET:        940 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       937
  Y_GRB_POS:       1100
  BINNING_INDEX:   1
  IM_URL:          sw00755867000msuni0306.fits
  SUN_POSTN:        73.04d {+04h 52m 10s}  +22.52d {+22d 31' 15"}
  SUN_DIST:         95.95 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
  MOON_POSTN:      202.19d {+13h 28m 46s}   -4.86d {-04d 51' 41"}
  MOON_DIST:       136.15 [deg]
  MOON_ILLUM:      81 [%]
  GAL_COORDS:       49.41,-59.61 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      338.12, -7.43 [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 Circular #21191
  K. L. Page (U Leicester), A. Cholden-Brown (PSU), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift Team:
  At 19:08:50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170604A (trigger=755867). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 342.645, -15.414 which is

     RA(J2000) = 22h 50m 35s
     Dec(J2000) = -15d 24' 50"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 25 sec. The peak count rate was ~2400 counts/sec (15-350 keV), at ~0 sec after the trigger.
  The XRT began observing the field at 19:10:55.1 UT, 124.7 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. However, the XRT TDRSS light curve suggests the presence of a bright, fading source; since no Photon Counting mode data were collected, no prompt source localisation can be performed. We are waiting for the full dataset to detect and localise the XRT counterpart.
  No results from UVOT are available at this time.
  Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 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 #21192
  L. Izzo, A. de Ugarte Postigo, Z. Cano, D.A. Kann (IAA-CSIC) report on behalf of a larger collaboration,
  We observed the field of GRB 170604A (Page et al., GCN 21191) with the T27 (Plane Wave CDK 0.70m) of the iTelescope.Net (http://www.itelescope.net ) located at Siding Spring, AU. A single image of 300 s each was taken in the R and in the V filters, starting at 19:32:07 UT, ~ 1400s after the GRB trigger. We detect a source not visible in PanSTARRS images at RA =3D 22:50:37.54 DEC =3D -15:24:44.4 (+- 0.5=E2=80=9D) with a preliminary magnitude of R ~ 17.5 (as compared to USNO-B 1.0 field stars), which we consider to be the afterglow.
  An image of the field can be seen at http://goo.gl/Rjmsk6
• GCN Circular #21195
  M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
  Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170604A (trigger #755867) (Page et al., GCN Circ. 21191). The BAT ground-calculated position is RA, Dec = 342.645, -15.406 deg which is

    RA(J2000)  =  22h 50m 34.9s
    Dec(J2000) = -15d 24' 20.1"
  

  with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 8%.
  The mask-weighted light curve shows several overlapping pulses that start at ~ T-12 s and end at ~T+20 s. The main peak occurs at ~T+3 s. T90 (15-350 keV) is 26.70 +- 6.21 sec (estimated error including systematics).
  The time-averaged spectrum from T-11.66 to T+22.58 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.31 +- 0.12. The fluence in the 15-150 keV band is 5.1 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.66 sec in the 15-150 keV band is 4.2 +- 0.9 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/755867/BA/
• GCN Circular #21196
  K.L. Page, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:
  Using 4539 s of XRT Photon Counting mode data and 10 UVOT images, 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 = 342.65623, -15.41233 which is equivalent to:

  RA (J2000):  22 50 37.49
  Dec (J2000): -15 24 44.4
  

  with an uncertainty of 1.4 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 is an official product of the Swift-XRT team.
• GCN Circular #21197
  L. Izzo, Z. Cano (IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. A. Kann (IAA-CSIC), C. C. Thoene (IAA-CSIC), A. Marante (GTC) and S. Geier (GTC, IAC) report on behalf of a larger collaboration:
  We observed the afterglow of GRB 170604A (Page et al., GCN Circ. 21191) using OSIRIS at the 10.4 m GTC telescope at La Palma (Spain). The observation consisted of 2x900s and 1x1200s exposures using the R1000B grism, which covers a wavelength range of 3700-7880 AA. Observations began at 04:14:19 UT on the morning of 05 June, 2017, at a mean epoch of +9.51 hrs from the GRB detection. The afterglow candidate (Izzo et al, GCN Circ. 21192) is detected in the r-band acquisition image, where we measure r = 20.3 +- 0.1 relative to nearby PANSTARRS standards in the GRB field of view.
  The afterglow spectrum shows a continuum through the observed wavelength range, and we identify absorption features corresponding to MgII, MgI, and FeII at a common redshift of z=1.329, which we identify as the redshift of GRB 170604A.
• GCN Circular #21198
  B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Cholden-Brown (PSU), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and K.L. Page report on behalf of the Swift-XRT team:
  We have analysed 7.6 ks of XRT data for GRB 170604A (Page et al. GCN Circ. 21191), from 110 s to 39.1 ks after the BAT trigger. The data comprise 308 s in Windowed Timing (WT) mode (the first 7 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. Using 4539 s of PC mode data and 10 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 342.65623, -15.41233 which is equivalent to:

  RA (J2000): 22h 50m 37.49s
  Dec(J2000): -15d 24' 44.4"
  

  with an uncertainty of 1.4 arcsec (radius, 90% confidence).
  The late-time light curve (from T0+3.8 ks) can be modelled with a power-law decay with a decay index of alpha=0.98 (+/-0.05).
  A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.27 (+/-0.04). The best-fitting absorption column is 1.95 (+/-0.11) x 10^21 cm^-2, in excess of the Galactic value of 3.8 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.85 (+/-0.09) and a best-fitting absorption column of 6.9 (+2.3, -2.2) x 10^20 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:

  Total column:	     6.9 (+2.3, -2.2) x 10^20 cm^-2
  Galactic foreground: 3.8 x 10^20 cm^-2
  Excess significance: 2.3 sigma
  Photon index:	     1.85 (+/-0.09)
  

  If the light curve continues to decay with a power-law decay index of 0.98, the count rate at T+24 hours will be 0.046 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.6 x 10^-12 (1.9 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/00755867.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #21200
  P. Schady (MPE) reports:
  We observed the field of GRB 170604A (Swift trigger 755867; Page et al., GCN #21191) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
  Observations started at 06:15 UT on 05-06-2017, 11.1 hours the GRB trigger. They were performed at an average seeing of 1.3" and at an average airmass of 2.
  We detect a point source within the 1.4" enhanced Swift/XRT error circle (Page et al., GCN 21196), and consistent with the afterglow position reported by Izzo et al. (GCN #21192).
  Based on a total exposure of 4.6 min in g'r'i'z' and 4 min in JHK, we estimate preliminary magnitudes (all in AB) of

  g' = 20.75 +/- 0.08
  r' = 20.46 +/- 0.05
  i' = 20.35 +/- 0.06
  z' = 20.21 +/- 0.08
  J = 19.6 +/- 0.1
  H = 19.6 +/- 0.3
  K > 19.6
  

  Given magnitudes are calibrated against PanSTARRS and 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.03 mag in the direction of the burst (Schlafly & Finkbeiner 2011).
  We acknowledge the excellent support provided by Simona Ciceri in obtaining these data.
• GCN Circular #21203
  E. Mazaeva (IKI), R. Inasaridze (AbAO), A. Pozanenko (IKI), A. Volnova (IKI), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), I. Molotov (KIAM), report on behalf of larger GRB follow-up collaboration:
  We observed the field of the Swift GRB 170604A (Page et al., GCN 21191) with AS-32 (0.7m) telescope of Abastumani Observatory starting on June, 04 (UT) 23:52:07. We obtained several unfiltered images of the field. Within enhanced XRT error circle (Page et al., GCN 21196) we detected the afterglow (Izzo et al, GCN 21192; Izzo et al, GCN 21197; Schady, , GCN 21200). Preliminary photometry of the afterglow is following

  Date        UT start   t-T0     Filter Exp.   OT   Err UpLim (3 sigma)
                         (mid, days)       (s)
  
  2017-06-04 23:52:07   0.19950   CR     5*60  19.13 0.18  21.0
  2017-06-05 00:00:50   0.20675   CR     7*60  19.23 0.16  21.1
  2017-06-05 00:13:02   0.21885   CR    13*60  19.30 0.22  20.6
  

  Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes)

  USNO-B.1_id    R2
  0746-0830331 14.71
  0746-0830367 14.76
  0746-0830438 15.14
  0746-0830455 14.77
  0747-0821123 14.60
  

• GCN Circular #21204
  Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
  We observed the field of GRB 170604A (Page, et al., GCN 21191) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2017/06 5.39 to 2017/06 5.45 UTC (14.19 to 15.70 hours after the BAT trigger), obtaining a total of 0.84 hours exposure in the r and i bands and 0.42 hours exposure in the Z and Y bands.
  For a source within the Swift-XRT error circle (Page, et al., GCN 21196), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections:

    r =3D 20.42 +/- 0.06
    i =3D 20.65 +/- 0.07
    Z =3D 20.45 +/- 0.13
    Y =3D 20.40 +/- 0.30
  

  These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
  We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
• GCN Circular #21207
  M. H. Siegel (PSU) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team:
  The Swift/UVOT began settled observations of the field of GRB 170604A 128 s after the BAT trigger (Page et al., GCN Circ. 21191). We detect a fading afterglow consistent with the position given by XRT (Page et al., GCN Circ 21196) and ground-based optical detections (Izzy et al., GCN Circ 21197; Schady, GCN Circ. 21200; Mazaeva et al., GCN Circ 21203).
  The preliminary UVOT position is:

      RA  (J2000) =  22:50:37.52 = 342.65632 (deg.)
      Dec (J2000) = -15:24:43.9  = -15.41220 (deg.)
  

  with an estimated uncertainty of 0.1 arc sec. (radius, 90% confidence).
  Preliminary magnitudes and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:

  Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
  
  white (fc)         128          278          147          15.81+-0.03
  white             3968         5603          393          18.72+-0.06
  white            39053        39959          885          20.57+-0.18
  v                 4378         6013          393          18.94+-0.31
  v                34480        44756         1268         >19.89
  b                 3763         5398          393          19.26+-0.15
  b                38141        39048          885         >20.86
  u (fc)             287          429          279          15.70+-0.03
  u                 4993         5193          196          18.51+-0.16
  u                28543        29132          576         >19.72
  uvw1              4788         4988          196          18.47+-0.19
  uvw1             23318        46354         1633          20.20+-0.27
  uvm2              4583         6169          344          18.58+-0.18
  uvm2             44762        45661          885         >20.37
  uvw2              4174         5809          393          19.53+-0.26
  uvw2             32392        40613         1700         >20.86
  

  The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
• GCN Circular #21247
  D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report:
  The long GRB 170604A (Swift-BAT trigger #736407: Page et al., GCN 21191; Stamatikos et al., GCN 21195; T0(BAT)=3D17:08:50.402 UT) was detected by Konus-Wind (KW) in the waiting mode.
  The light curve shows a single peak with a duration of ~30 s. Modeling the KW 3-channel time-integrated spectrum (from T0(BAT)-16.155 s to T0(BAT)+10.341 s) by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha =3D -1.31(-0.20,+0.26) and Ep =3D 220(-48,+72) keV. The energy fluence for this time interval is (1.03 =B1 0.13)x10^-5 erg/cm2, and the peak energy flux, measured on a 2.944 s scale from T0(BAT)+1.509 s is (6.9 =B1 0.13)x10^-7 erg/cm2/s, both in the 20 keV-10 MeV range.
  Assuming the redshift z=3D1.329 (Izzo et al., GCN 21197) and a standard cosmology model with H_0 =3D 70 km/s/Mpc, Omega_M =3D 0.30, and Omega_Lambda =3D 0.70, we estimate the burst isotropic energy release E_iso to (4.7 =B1 0.6)x10^52 erg, and the rest-frame peak energy of the time-integrated spectrum, Ep,z, to 512(-112,+168) keV.
  The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB170604A/
  All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.