Gamma-ray Burst 170524A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 19:49:27 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     754322,   Seg_Num: 0
GRB_RA:          319.456d {+21h 17m 49s} (J2000),
                 319.607d {+21h 18m 26s} (current),
                 319.021d {+21h 16m 05s} (1950)
GRB_DEC:         +48.587d {+48d 35' 15"} (J2000),
                 +48.661d {+48d 39' 40"} (current),
                 +48.377d {+48d 22' 36"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       501 [cnts]    Image_Peak=71 [image_cnts]
TRIGGER_DUR:     0.064 [sec] 
TRIGGER_INDEX:   10418     E_range: 25-100 keV
BKG_INTEN:       20969 [cnts]
BKG_TIME:        71340.88 SOD {19:49:00.88} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17897 TJD;   144 DOY;   17/05/24
GRB_TIME:        71355.28 SOD {19:49:15.28} UT
GRB_PHI:         -77.42 [deg]
GRB_THETA:        10.95 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     24.87 [sigma]
IMAGE_SIGNIF:    9.12 [sigma]
MERIT_PARAMS:     +1  +0  +0  -4  +2  +0  +0  +1 -13  +0 
SUN_POSTN:        61.82d {+04h 07m 18s}  +20.91d {+20d 54' 47"}
SUN_DIST:         82.10 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.58d {+03h 14m 20s}  +12.92d {+12d 55' 05"}
MOON_DIST:        79.67 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.85, -0.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      349.17, 59.22 [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 = 164.33,15.08 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 19:50:30 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.432d {+21h 17m 44s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 51"} (J2000)
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71416.00 SOD {19:50:16.00} UT,   60.7 [sec] since BAT Trigger Time
COUNTS:          34    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        4    Max_iter_allowed= 4
ERROR_CODE:      2
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        Algorithm did not converge; too many iterations.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 19:52:44 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     754322,   Seg_Num: 0
GRB_RA:          319.456d {+21h 17m 49s} (J2000),
                 319.607d {+21h 18m 26s} (current),
                 319.021d {+21h 16m 05s} (1950)
GRB_DEC:         +48.587d {+48d 35' 15"} (J2000),
                 +48.661d {+48d 39' 40"} (current),
                 +48.377d {+48d 22' 36"} (1950)
GRB_DATE:        17897 TJD;   144 DOY;   17/05/24
GRB_TIME:        71355.50 SOD {19:49:15.50} UT
TRIGGER_INDEX:   10418
GRB_PHI:         -77.42 [deg]
GRB_THETA:        10.95 [deg]
DELTA_TIME:      -21.00 [sec]
TRIGGER_DUR:     0.064 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     24.87 [sigma]
IMAGE_SIGNIF:    9.12 [sigma]
LC_URL:          sw00754322000msb.lc
SUN_POSTN:        61.83d {+04h 07m 18s}  +20.91d {+20d 54' 48"}
SUN_DIST:         82.10 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.62d {+03h 14m 29s}  +12.93d {+12d 55' 36"}
MOON_DIST:        79.68 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.85, -0.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      349.17, 59.22 [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 = 164.33,15.08 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 19:53:22 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.432d {+21h 17m 44s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
POINT_ROLL:      67.018d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71422.33 SOD {19:50:22.33} UT,   67.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.618
N_STARS:         190
X_OFFSET:        603 [pixels]
Y_OFFSET:        489 [pixels]
X_MAX:           1562 [pixels]
Y_MAX:           1448 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00754322000msufc0067.fits
SUN_POSTN:        61.83d {+04h 07m 18s}  +20.91d {+20d 54' 48"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.63d {+03h 14m 30s}  +12.93d {+12d 55' 42"}
MOON_DIST:        79.70 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.84, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 19:53:32 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.432d {+21h 17m 44s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
POINT_ROLL:      67.018d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71422.33 SOD {19:50:22.33} UT,   67.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.618
N_STARS:         190
X_OFFSET:        603 [pixels]
Y_OFFSET:        489 [pixels]
X_MAX:           1562 [pixels]
Y_MAX:           1448 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00754322000msufc0067.fits
SUN_POSTN:        61.83d {+04h 07m 18s}  +20.91d {+20d 54' 48"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.63d {+03h 14m 31s}  +12.93d {+12d 55' 44"}
MOON_DIST:        79.71 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.84, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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:     Wed 24 May 17 19:55:11 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.432d {+21h 17m 44s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
ROLL:            67.018d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71422.33 SOD {19:50:22.33} UT,   67.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     517348241
X_OFFSET:        922 [pixels]
Y_OFFSET:        808 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       968
BINNING_INDEX:   1
IM_URL:          sw00754322000msuni0087.fits
SUN_POSTN:        61.83d {+04h 07m 19s}  +20.91d {+20d 54' 49"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.64d {+03h 14m 35s}  +12.93d {+12d 55' 60"}
MOON_DIST:        79.71 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.84, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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:     Wed 24 May 17 19:55:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.432d {+21h 17m 44s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
ROLL:            67.018d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71422.33 SOD {19:50:22.33} UT,   67.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     517348241
X_OFFSET:        922 [pixels]
Y_OFFSET:        808 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       968
BINNING_INDEX:   1
IM_URL:          sw00754322000msuni0087.fits
SUN_POSTN:        61.83d {+04h 07m 19s}  +20.91d {+20d 54' 49"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.65d {+03h 14m 35s}  +12.93d {+12d 56' 02"}
MOON_DIST:        79.71 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.84, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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:     Wed 24 May 17 19:56:39 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     754322,   Seg_Num: 0
GRB_RA:          319.4831d {+21h 17m 55.94s} (J2000),
                 319.6346d {+21h 18m 32.30s} (current),
                 319.0479d {+21h 16m 11.50s} (1950)
GRB_DEC:         +48.6072d {+48d 36' 25.9"} (J2000),
                 +48.6809d {+48d 40' 51.2"} (current),
                 +48.3962d {+48d 23' 46.4"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71438.00 SOD {19:50:38.00} UT,   82.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        61.83d {+04h 07m 19s}  +20.91d {+20d 54' 50"}
SUN_DIST:         82.08 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.66d {+03h 14m 38s}  +12.94d {+12d 56' 14"}
MOON_DIST:        79.68 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       90.88, -0.51 [deg] galactic lon,lat of the burst
ECL_COORDS:      349.22, 59.22 [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 1.1% < P(seren) < 2.8%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 20:02:28 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.428d {+21h 17m 43s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
POINT_ROLL:      67.014d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71634.53 SOD {19:53:54.53} UT,   279.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.394
N_STARS:         190
X_OFFSET:        363 [pixels]
Y_OFFSET:        249 [pixels]
X_MAX:           1802 [pixels]
Y_MAX:           1688 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00754322000msufc0279.fits
SUN_POSTN:        61.83d {+04h 07m 20s}  +20.91d {+20d 54' 52"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.72d {+03h 14m 53s}  +12.95d {+12d 57' 09"}
MOON_DIST:        79.75 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.83, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 20:02:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.428d {+21h 17m 43s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
POINT_ROLL:      67.014d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71634.53 SOD {19:53:54.53} UT,   279.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.394
N_STARS:         190
X_OFFSET:        363 [pixels]
Y_OFFSET:        249 [pixels]
X_MAX:           1802 [pixels]
Y_MAX:           1688 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00754322000msufc0279.fits
SUN_POSTN:        61.83d {+04h 07m 20s}  +20.91d {+20d 54' 52"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.72d {+03h 14m 53s}  +12.95d {+12d 57' 11"}
MOON_DIST:        79.75 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.83, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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:     Wed 24 May 17 20:03:21 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     754322,   Seg_Num: 0
GRB_RA:          319.4868d {+21h 17m 56.83s} (J2000),
                 319.6383d {+21h 18m 33.19s} (current),
                 319.0516d {+21h 16m 12.38s} (1950)
GRB_DEC:         +48.6064d {+48d 36' 23.0"} (J2000),
                 +48.6801d {+48d 40' 48.3"} (current),
                 +48.3954d {+48d 23' 43.5"} (1950)
GRB_ERROR:       4.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71438.00 SOD {19:50:38.00} UT,   82.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        61.83d {+04h 07m 20s}  +20.91d {+20d 54' 53"}
SUN_DIST:         82.08 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.73d {+03h 14m 55s}  +12.95d {+12d 57' 18"}
MOON_DIST:        79.71 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.88, -0.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      349.22, 59.22 [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:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 1.1% < P(seren) < 2.8%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 20:03:55 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.428d {+21h 17m 43s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
ROLL:            67.014d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71634.53 SOD {19:53:54.53} UT,   279.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     517348453
X_OFFSET:        922 [pixels]
Y_OFFSET:        808 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       968
BINNING_INDEX:   1
IM_URL:          sw00754322000msuni0299.fits
SUN_POSTN:        61.83d {+04h 07m 20s}  +20.91d {+20d 54' 53"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.74d {+03h 14m 57s}  +12.96d {+12d 57' 23"}
MOON_DIST:        79.76 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.83, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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:     Wed 24 May 17 20:04:09 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.428d {+21h 17m 43s} (J2000)
POINT_DEC:       +48.581d {+48d 34' 50"} (J2000)
ROLL:            67.014d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  71634.53 SOD {19:53:54.53} UT,   279.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     517348453
X_OFFSET:        922 [pixels]
Y_OFFSET:        808 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       968
BINNING_INDEX:   1
IM_URL:          sw00754322000msuni0299.fits
SUN_POSTN:        61.83d {+04h 07m 20s}  +20.91d {+20d 54' 53"}
SUN_DIST:         82.12 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.74d {+03h 14m 57s}  +12.96d {+12d 57' 25"}
MOON_DIST:        79.76 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.83, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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 #21135
J.G. Gropp (PSU), S. D. Barthelmy (GSFC), C. Gronwall (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC) and D. M. Palmer (LANL) report on behalf of the Swift Team:
At 19:49:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170524A (trigger=754322). Swift slewed immediately to the source. The BAT on-board calculated location is RA, Dec 319.456, +48.587, which is
```
   RA(J2000)  =  21h 17m 49s
   Dec(J2000) = +48d 35' 15"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 0.25 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 19:50:16.0 UT, 60.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 319.4869, 48.6065 which is equivalent to:
```
   RA(J2000)  = 21h 17m 56.86s
   Dec(J2000) = +48d 36' 23.4"
```
with an uncertainty of 4.1 arcseconds (radius, 90% containment). This location is 101 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 does not constrain the column density.
UVOT took a finding chart exposure of 150 seconds with the White filter starting 67 seconds after the BAT trigger. 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 circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain extinction expected.
We note that this is a short burst, close to the Galactic plane (lat = -0.5 degrees), although far from the Galactic center (lon = 91 degrees). Thus there is a possibility that this is a previously unknown Soft Gamma Repeater (SGR). However, the preliminary 4-energy lightcurve shows more flux above 100 keV than is typical for an SGR burst.
Burst Advocate for this burst is J.G. Gropp (jdg44 AT psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 20:11:25 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.428d {+21h 17m 43s} (J2000)
POINT_DEC:       +48.580d {+48d 34' 49"} (J2000)
POINT_ROLL:      67.014d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  72212.61 SOD {20:03:32.61} UT,   857.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.104
N_STARS:         190
X_OFFSET:        363 [pixels]
Y_OFFSET:        249 [pixels]
X_MAX:           1802 [pixels]
Y_MAX:           1688 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw00754322000msufc0857.fits
SUN_POSTN:        61.84d {+04h 07m 21s}  +20.92d {+20d 54' 56"}
SUN_DIST:         82.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.81d {+03h 15m 15s}  +12.98d {+12d 58' 34"}
MOON_DIST:        79.79 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.83, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 24 May 17 20:11:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     754322,   Seg_Num: 0
POINT_RA:        319.428d {+21h 17m 43s} (J2000)
POINT_DEC:       +48.580d {+48d 34' 49"} (J2000)
POINT_ROLL:      67.014d
IMG_START_DATE:  17897 TJD;   144 DOY;   17/05/24
IMG_START_TIME:  72212.61 SOD {20:03:32.61} UT,   857.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.104
N_STARS:         190
X_OFFSET:        363 [pixels]
Y_OFFSET:        249 [pixels]
X_MAX:           1802 [pixels]
Y_MAX:           1688 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw00754322000msufc0857.fits
SUN_POSTN:        61.84d {+04h 07m 21s}  +20.92d {+20d 54' 57"}
SUN_DIST:         82.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:       48.82d {+03h 15m 16s}  +12.98d {+12d 58' 37"}
MOON_DIST:        79.80 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       90.83, -0.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      349.13, 59.22 [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 Circular #21136
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 467 s of XRT Photon Counting mode data and 1 UVOT images for GRB 170524A, 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 = 319.48641, +48.60687 which is equivalent to:
```
RA (J2000): 21h 17m 56.74s
Dec (J2000): +48d 36' 24.7"
```
with an uncertainty of 4.3 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 #21139
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Cholden-Brown (PSU), S.L. Gibson (U. Leicester) and J.G. Gropp report on behalf of the Swift-XRT team:
We have analysed 9.9 ks of XRT data for GRB 170524A (Gropp et al. GCN Circ. 21135), from 69 s to 46.6 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 21136). There is evidence that the source may be fading, however we cannot constrain the decay at the current time
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00754322.
This circular is an official product of the Swift-XRT team.
GCN Circular #21140
Jan =C5=A0trobl, Ren=C3=A9 Hudec and Martin Jel=C3=ADnek (AS=C3=9A CAS, Ond=C5=99ejov, CZ)
We observed the location of the recently discovered GRB 170524A (Gropp et al., GCNC 21135) with the 0.5m robotic telescope D50 located in Ond=C5=99ejov, Czech Republic. The unfiltered CCD observations started 4 hours after the trigger, once the position got available above local horizon, and had to be interrupted after 20 minutes because of passing clouds. The sum of all images obtained has a mean exposure time 00:02:23UT, i.e. 4.22h after the GRB, and a limiting magnitude of R>20.2. No object was detected within the XRT errorbox (Evans et al., GCNC 21136).
GCN Circular #21141
S.W.K. Emery (UCL-MSSL) and J.G. Gropp (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170524A 67 s after the BAT trigger (Gropp et al., GCN Circ. 21135). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 21136) is detected in the initial UVOT exposures. Preliminary 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            67          217          147         >20.4
u_FC               280          529          246         >19.5
white               67         1007          334         >20.6
v                  610         1058           58         >17.9
b                  535         1157           58         >18.7
u                  280         1132          285         >19.5
w1                 660         1107           58         >18.3
m2                1063         1082           19         >17.3
w2                 586         1033           58         >18.6
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 2.82 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #21143
A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), J.G. Gropp (PSU), H. A. Krimm (NSF/USRA), 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+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170524A (trigger #754322) (Gropp et al., GCN Circ. 21135). The BAT ground-calculated position is RA, Dec = 319.488, 48.603 deg which is
```
  RA(J2000)  =  21h 17m 57.2s
  Dec(J2000) = +48d 36' 12.5"
```
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%.
The mask-weighted light curve shows a double peaked structure with the first pulse from ~T0 to ~T+0.05, and second pulse from ~T+0.05 to ~T+0.1. T90 (15-350 keV) is 0.10 +- 0.02 sec (estimated error including systematics).
The time-averaged spectrum from T+0.00 to T+0.12 sec fit by a simple power-law model shows the power law index of 1.07 +- 0.24 (chi squared 47.68 for 57 d.o.f.). The fluence in the 15-150 keV band is 3.7 +- 0.6 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.44 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec.
A single blackbody fit to the time-averaged spectrum shows the blackbody temperature of 21.09 +- 3.99 keV (chi squared 51.91 for 57 d.o.f.). A thermal bremsstrahlung model fit shows the temperature of 199.36 +- -80.44 keV (chi squared 57.87 for 57 d.o.f.). A double blackbody fit shows the lower temperature of 5.84 (error not unconstrained) keV and the higher temperature of 25.96 +15.56 keV (chi squared 45.99 for 55 d.o.f.). All the quoted errors are at the 90% confidence level.
The photon index of ~ 1 using the simple power-law model is consistent with those from the BAT-detected short GRBs (Lien & Sakamoto et al. 2016), and harder than the spectra of many BAT-detected SGRs, which have photon index ~ 3. In addition, the double-peaked structure seen in this burst is not commonly observed in the BAT light curves of SGRs (with time bins >= 2 ms).
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/754322/BA/
GCN Circular #21145
E. Mazaeva (IKI), S. Nazarov (CrAO), A. Kusakin (Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 170524A (trigger=754322) (Gropp et al., GCN 21135) with Zeiss-1000 (East) of Tien Shan Astronomical Observatory and AZT-8 telescope of CrAO. We obtained several images in R filter. The TSHAO observations started on 2017-05-24 (UT) 20:31:45 under not optimal weather conditions. Observations in CrAO started on 2017-05-25 (UT) 00:18:50. Within enhanced XRT position (Evans et al. GCN 21136) we did not detect any optical source in the first epoch. In the second epoch (CrAO observation) we detected an object which is on the edge of the enhanced XRT position. The object has coordinates (J2000) 21:17:56.30 +48:36:27.9 with uncertainties of about 1 arcsec in each coordinate and brightness of R=20.10 +/- 0.15 at 0.1992 days after the Swift trigger. For now we can not say anything about the object variability. However the object is barely visible in DSS2 (Red). The preliminary results of field photometry are as follows
```
Date       UT start   t-T0   Filter  Exp.      UL(3 sigma)
                       (mid, days)    (s)

2017-05-24 20:31:45 0.06857  R       46*120    20.3
2017-05-25 00:18:50 0.19920  R       10*180    21.5
```
Photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id R2
1386-0392957 16.69
1385-0394718 17.29
1386-0392907 17.11
The finding chart of the object can be found at http://grb.rssi.ru/GRB170524A/GRB170524A_CrAO_170524.png
GCN Circular #21152
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 170524A (Gropp, et al., GCN 21135) 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 2017/05 25.40 to 2017/05 25.46 UTC (13.79 to 15.29 hours after the BAT trigger), obtaining a total of 1.06 hours exposure in the r and i bands and 0.36 hours exposure in the Z, Y, J, and H bands.
We again observed from 2017/05 26.32 to 2017/05 26.47 UTC (35.77 to 39.48 hours after the BAT trigger), obtaining a total of 2.42 hours exposure in the r and i bands and 1.01 hours exposure in the Z, Y, J, and H bands.
For a source within the Swift-XRT error circle (Evans, et al., GCN 21136), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma):
```
     5/25      5/26
  r  > 24.45   > 25.66
  i  > 23.25   > 24.52
  Z  > 21.72   > 23.00
  Y  > 21.26   > 22.57
  J  > 18.16   > 21.25
  H  > 17.83   > 21.50
```
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 #21212
K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)
The AMI Large Array robotically triggered on the Swift alert for GRB 170524A (Gropp et al., GCN 21135) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2016 May 25.03, May 26.26, May 28.18 and Jun 01.20 (UT) do not reveal any radio source at the XRT location (Evans et al., GCN 21136), with 3sigma upper limits of 162 uJy, 207 uJy, 120 uJy and 126 uJy respectively.
We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.

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Jochen Greiner, last update: 08-Jun-2017 [Disclaimer]