Gamma-ray Burst 170516A

(All information courtesy of the instrument teams.)

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:49:37 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     753110,   Seg_Num: 0
GRB_RA:           41.598d {+02h 46m 24s} (J2000),
                  41.726d {+02h 46m 54s} (current),
                  41.231d {+02h 44m 55s} (1950)
GRB_DEC:         -55.899d {-55d 53' 54"} (J2000),
                 -55.826d {-55d 49' 34"} (current),
                 -56.107d {-56d 06' 26"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3555 [cnts]    Image_Peak=154 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   137     E_range: 15-50 keV
BKG_INTEN:       23105 [cnts]
BKG_TIME:        46148.93 SOD {12:49:08.93} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17889 TJD;   136 DOY;   17/05/16
GRB_TIME:        46160.57 SOD {12:49:20.57} UT
GRB_PHI:          26.10 [deg]
GRB_THETA:        29.36 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     10.29 [sigma]
IMAGE_SIGNIF:    7.32 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +1  -3  +0  +0 -24  +0 
SUN_POSTN:        53.52d {+03h 34m 05s}  +19.22d {+19d 13' 00"}
SUN_DIST:         75.71 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.86d {+19h 55m 27s}  -18.14d {-18d 08' 30"}
MOON_DIST:        82.02 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.20,-54.60 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        1.66,-65.20 [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 = 345.58,17.31 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:51:12 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     753110,   Seg_Num: 0
GRB_RA:           41.5663d {+02h 46m 15.91s} (J2000),
                  41.6941d {+02h 46m 46.58s} (current),
                  41.1988d {+02h 44m 47.70s} (1950)
GRB_DEC:         -55.9092d {-55d 54' 33.1"} (J2000),
                 -55.8369d {-55d 50' 12.8"} (current),
                 -56.1181d {-56d 07' 05.1"} (1950)
GRB_ERROR:       6.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       4.96e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.38 [sigma]
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46241.14 SOD {12:50:41.14} UT,   80.6 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.22 261.57 243.49
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        53.52d {+03h 34m 05s}  +19.22d {+19d 13' 01"}
SUN_DIST:         75.72 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.88d {+19h 55m 30s}  -18.14d {-18d 08' 25"}
MOON_DIST:        82.00 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.24,-54.60 [deg] galactic lon,lat of the burst
ECL_COORDS:        1.61,-65.20 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.24 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:51:25 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     753110,   Seg_Num: 0
GRB_RA:           41.5663d {+02h 46m 15.9s} (J2000),
                  41.6941d {+02h 46m 46.5s} (current),
                  41.1988d {+02h 44m 47.7s} (1950)
GRB_DEC:         -55.9092d {-55d 54' 33.1"} (J2000),
                 -55.8369d {-55d 50' 12.8"} (current),
                 -56.1181d {-56d 07' 05.1"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       29 [cnts]
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46241.14 SOD {12:50:41.14} UT,   80.6 [sec] since BAT Trigger Time
CENTROID_X:      366.34,  raw= 366  [pixels]
CENTROID_Y:      341.79,  raw= 342  [pixels]
ROLL:            11.60 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   102.30
GRB_POS_XRT_Z:   141.32
IMAGE_URL:       sw00753110000msxps_rw.img
SUN_POSTN:        53.52d {+03h 34m 05s}  +19.22d {+19d 13' 01"}
SUN_DIST:         75.72 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.88d {+19h 55m 31s}  -18.14d {-18d 08' 24"}
MOON_DIST:        82.00 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.24,-54.60 [deg] galactic lon,lat of the burst
ECL_COORDS:        1.61,-65.20 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:51:22 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     753110,   Seg_Num: 0
GRB_RA:           41.5663d {+02h 46m 15.9s} (J2000),
                  41.6941d {+02h 46m 46.5s} (current),
                  41.1988d {+02h 44m 47.7s} (1950)
GRB_DEC:         -55.9092d {-55d 54' 33.1"} (J2000),
                 -55.8369d {-55d 50' 12.8"} (current),
                 -56.1181d {-56d 07' 05.1"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       29 [cnts]
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46241.14 SOD {12:50:41.14} UT,   80.6 [sec] since BAT Trigger Time
CENTROID_X:      366.34,  raw= 366  [pixels]
CENTROID_Y:      341.79,  raw= 342  [pixels]
ROLL:            11.60 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   102.30
GRB_POS_XRT_Z:   141.32
IMAGE_URL:       sw00753110000msxps_rw.img
SUN_POSTN:        53.52d {+03h 34m 05s}  +19.22d {+19d 13' 01"}
SUN_DIST:         75.72 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.88d {+19h 55m 31s}  -18.14d {-18d 08' 24"}
MOON_DIST:        82.00 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.24,-54.60 [deg] galactic lon,lat of the burst
ECL_COORDS:        1.61,-65.20 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:53:01 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     753110,   Seg_Num: 0
GRB_RA:           41.598d {+02h 46m 24s} (J2000),
                  41.726d {+02h 46m 54s} (current),
                  41.231d {+02h 44m 55s} (1950)
GRB_DEC:         -55.899d {-55d 53' 54"} (J2000),
                 -55.826d {-55d 49' 34"} (current),
                 -56.107d {-56d 06' 26"} (1950)
GRB_DATE:        17889 TJD;   136 DOY;   17/05/16
GRB_TIME:        46160.57 SOD {12:49:20.57} UT
TRIGGER_INDEX:   137
GRB_PHI:          26.10 [deg]
GRB_THETA:        29.36 [deg]
DELTA_TIME:      -43.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     10.29 [sigma]
IMAGE_SIGNIF:    7.32 [sigma]
LC_URL:          sw00753110000msb.lc
SUN_POSTN:        53.52d {+03h 34m 06s}  +19.22d {+19d 13' 02"}
SUN_DIST:         75.71 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.89d {+19h 55m 34s}  -18.14d {-18d 08' 18"}
MOON_DIST:        82.01 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.20,-54.60 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        1.66,-65.20 [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 = 345.58,17.31 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:55:38 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
POINT_ROLL:      11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46247.85 SOD {12:50:47.85} UT,   87.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.851
N_STARS:         12
X_OFFSET:        264 [pixels]
Y_OFFSET:        576 [pixels]
X_MAX:           1223 [pixels]
Y_MAX:           1535 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw00753110000msufc0087.fits
SUN_POSTN:        53.52d {+03h 34m 06s}  +19.22d {+19d 13' 04"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.92d {+19h 55m 40s}  -18.14d {-18d 08' 09"}
MOON_DIST:        82.02 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:55:53 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
POINT_ROLL:      11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46247.85 SOD {12:50:47.85} UT,   87.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.851
N_STARS:         12
X_OFFSET:        264 [pixels]
Y_OFFSET:        576 [pixels]
X_MAX:           1223 [pixels]
Y_MAX:           1535 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw00753110000msufc0087.fits
SUN_POSTN:        53.53d {+03h 34m 06s}  +19.22d {+19d 13' 04"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.92d {+19h 55m 40s}  -18.14d {-18d 08' 08"}
MOON_DIST:        82.02 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [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:     Tue 16 May 17 12:58:13 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
ROLL:            11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46247.85 SOD {12:50:47.85} UT,   87.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     516631866
X_OFFSET:        448 [pixels]
Y_OFFSET:        848 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       608
Y_GRB_POS:       1008
BINNING_INDEX:   1
IM_URL:          sw00753110000msuni0107.fits
SUN_POSTN:        53.53d {+03h 34m 06s}  +19.22d {+19d 13' 05"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.94d {+19h 55m 45s}  -18.13d {-18d 08' 00"}
MOON_DIST:        82.01 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 12:58:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
ROLL:            11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46247.85 SOD {12:50:47.85} UT,   87.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     516631866
X_OFFSET:        448 [pixels]
Y_OFFSET:        848 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       608
Y_GRB_POS:       1008
BINNING_INDEX:   1
IM_URL:          sw00753110000msuni0107.fits
SUN_POSTN:        53.53d {+03h 34m 06s}  +19.22d {+19d 13' 05"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.94d {+19h 55m 45s}  -18.13d {-18d 08' 00"}
MOON_DIST:        82.01 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 13:03:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
POINT_ROLL:      11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46459.86 SOD {12:54:19.86} UT,   299.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.256
N_STARS:         10
X_OFFSET:        128 [pixels]
Y_OFFSET:        528 [pixels]
X_MAX:           1087 [pixels]
Y_MAX:           1487 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00753110000msufc0299.fits
SUN_POSTN:        53.53d {+03h 34m 07s}  +19.22d {+19d 13' 08"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.98d {+19h 55m 55s}  -18.13d {-18d 07' 43"}
MOON_DIST:        82.00 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.  
COMMENTS:        The Pointing RA,Dec,Roll values came from the 1st SrcList Notice.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 13:03:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
POINT_ROLL:      11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46459.86 SOD {12:54:19.86} UT,   299.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.256
N_STARS:         10
X_OFFSET:        128 [pixels]
Y_OFFSET:        528 [pixels]
X_MAX:           1087 [pixels]
Y_MAX:           1487 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00753110000msufc0299.fits
SUN_POSTN:        53.53d {+03h 34m 07s}  +19.22d {+19d 13' 08"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.98d {+19h 55m 56s}  -18.13d {-18d 07' 42"}
MOON_DIST:        82.00 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [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:     Tue 16 May 17 13:04:21 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
ROLL:            11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46459.86 SOD {12:54:19.86} UT,   299.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     516632078
X_OFFSET:        448 [pixels]
Y_OFFSET:        848 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       608
Y_GRB_POS:       1008
BINNING_INDEX:   1
IM_URL:          sw00753110000msuni0319.fits
SUN_POSTN:        53.53d {+03h 34m 07s}  +19.22d {+19d 13' 09"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.99d {+19h 55m 58s}  -18.13d {-18d 07' 38"}
MOON_DIST:        81.99 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The Pointing RA,Dec,Roll values came from the 1st Image Notice.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 16 May 17 13:04:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     753110,   Seg_Num: 0
POINT_RA:         41.630d {+02h 46m 31s} (J2000)
POINT_DEC:       -55.876d {-55d 52' 34"} (J2000)
ROLL:            11.603d
IMG_START_DATE:  17889 TJD;   136 DOY;   17/05/16
IMG_START_TIME:  46459.86 SOD {12:54:19.86} UT,   299.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     516632078
X_OFFSET:        448 [pixels]
Y_OFFSET:        848 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       608
Y_GRB_POS:       1008
BINNING_INDEX:   1
IM_URL:          sw00753110000msuni0319.fits
SUN_POSTN:        53.53d {+03h 34m 07s}  +19.22d {+19d 13' 09"}
SUN_DIST:         75.68 [deg]   Sun_angle= 0.8 [hr] (West of Sun)
MOON_POSTN:      298.99d {+19h 55m 58s}  -18.13d {-18d 07' 37"}
MOON_DIST:        81.99 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:      275.15,-54.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        1.72,-65.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position 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 #21097
A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA), P.A. Evans (U Leicester), C. Gronwall (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 12:49:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170516A (trigger=753110). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 41.598, -55.899, which is
```
   RA(J2000)  =  02h 46m 24s
   Dec(J2000) = -55d 53' 54"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a couple peaks with a total duration of about 35 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~3 sec after the trigger.
The XRT began observing the field at 12:50:41.1 UT, 80.5 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 41.5663, -55.9092 which is equivalent to:
```
   RA(J2000)  = +02h 46m 15.91s
   Dec(J2000) = -55d 54' 33.1"
```
with an uncertainty of 6.4 arcseconds (radius, 90% containment). This location is 73 arcseconds from the BAT onboard position, within the BAT error circle.
The initial flux in the 2.5 s image was 4.96e-10 erg cm^-2 s^-1 (0.2-10 keV).
Automated UVOT data processing is currently not working, but manual inspection of the UVOT image shows no GRB afterglow counterpart.
Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #21098
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 2335 s of XRT Photon Counting mode data and 6 UVOT images for GRB 170516A, 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 = 41.56858, -55.90968 which is equivalent to:
```
RA (J2000): 02h 46m 16.46s
Dec (J2000): -55d 54' 34.8"
```
with an uncertainty of 1.8 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 #21099
N. P. M. Kuin (UCL-MSSL) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170516A 87 s after the BAT trigger (Lien et al., GCN Circ. 21097). No optical afterglow consistent with the XRT position (Lien et al. GCN Circ. 21097) 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            87          237          147         >20.1
white               87         5703          541         >21.1
v                 4478         6113          393         >19.8
b                 3863         5498          393         >20.6
u                  299         5293          379         >19.4
w1                4888         5088          197         >19.4
m2                4683         6222          299         >20.5
w2                4274         5909          393         >20.5
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #21101
D.N. Burrows (PSU), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and A.Y. Lien report on behalf of the Swift-XRT team:
We have analysed 7.2 ks of XRT data for GRB 170516A (Lien et al. GCN Circ. 21097), from 69 s to 34.9 ks after the BAT trigger. The data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 21098).
The light curve can be modelled with an initial power-law decay with an index of alpha=3.78 (+4.22, -0.29), followed by a break at T+232 s to an alpha of 0.55 (+/-0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.07 (+0.25, -0.23). The best-fitting absorption column is 9.1 (+6.2, -5.2) x 10^20 cm^-2, in excess of the Galactic value of 3.1 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.2 x 10^-11 (3.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     9.1 (+6.2, -5.2) x 10^20 cm^-2
Galactic foreground: 3.1 x 10^20 cm^-2
Excess significance: 1.9 sigma
Photon index:	     2.07 (+0.25, -0.23)
```
If the light curve continues to decay with a power-law decay index of 0.55, the count rate at T+24 hours will be 0.015 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.9 x 10^-13 (6.0 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00753110.
This circular is an official product of the Swift-XRT team.
GCN Circular #21102
J. R. Cummings (CPI), S. D. Barthelmy (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170516A (trigger #753110) (Lien, et al., GCN Circ. 21097). The BAT ground-calculated position is RA, Dec = 41.543, -55.929 deg which is
```
    RA(J2000)  =  02h 46m 10.4s
    Dec(J2000) = -55d 55' 44.2"
```
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 67%.
The mask-weighted light curve shows two fairly symmetrical triangular peaks. The first starts at T-5 s, peaks at T+2 s and decays by T+10 s. The second peak starts at T+10 s, has a broad peak from T+15 to T+20 and decays by T+28 s. The spacecraft slewed away from the burst position at about T+550 sec. T90 (15-350 keV) is 36.78 +- 11.61 sec (estimated error including systematics).
The time-averaged spectrum from T-19.86 to T+31.22 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.13 +- 0.87, and Epeak of 19.1 +- 12.4 keV (chi squared 37.46 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 8.5 +- 0.9 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T+1.27 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.67 +- 0.17 (chi squared 47.73 for 57 d.o.f.). 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/753110/BA/

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Jochen Greiner, last update: 17-May-2017 [Disclaimer]