Gamma-ray Burst 080721

(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:     Mon 21 Jul 08 10:25:42 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     317508,   Seg_Num: 0
GRB_RA:          224.471d {+14h 57m 53s} (J2000),
                 224.587d {+14h 58m 21s} (current),
                 223.790d {+14h 55m 10s} (1950)
GRB_DEC:         -11.712d {-11d 42' 43"} (J2000),
                 -11.746d {-11d 44' 45"} (current),
                 -11.512d {-11d 30' 43"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       14091 [cnts]    Image_Peak=271 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   155     E_range: 50-350 keV
BKG_INTEN:       32932 [cnts]
BKG_TIME:        37501.04 SOD {10:25:01.04} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14668 TJD;   203 DOY;   08/07/21
GRB_TIME:        37516.97 SOD {10:25:16.97} UT
GRB_PHI:           3.23 [deg]
GRB_THETA:        56.52 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     142.33 [sigma]
IMAGE_SIGNIF:    10.24 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +3 +28  +0  +0 +27  +1 
SUN_POSTN:       121.16d {+08h 04m 40s}  +20.35d {+20d 21' 09"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.33d {+22h 25m 18s}   -8.31d {-08d 18' 37"}
MOON_DIST:       109.23 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.39, 40.51 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      225.46,  4.97 [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 = 128.41,-20.50 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:27:51 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     317508,   Seg_Num: 0
GRB_RA:          224.4831d {+14h 57m 55.9s} (J2000),
                 224.5996d {+14h 58m 23.9s} (current),
                 223.8027d {+14h 55m 12.6s} (1950)
GRB_DEC:         -11.7241d {-11d 43' 26.7"} (J2000),
                 -11.7580d {-11d 45' 28.9"} (current),
                 -11.5243d {-11d 31' 27.5"} (1950)
GRB_ERROR:       -773094113.3 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       162 [cnts]
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37624.12 SOD {10:27:04.12} UT,   107.2 [sec] since BAT Trigger Time
CENTROID_X:      299.40,  raw= 299  [pixels]
CENTROID_Y:      195.22,  raw= 195  [pixels]
ROLL:            288.10 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -242.27
GRB_POS_XRT_Z:   -6.83
IMAGE_URL:       sw00317508000msxps_rw.img
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 08"}
SUN_DIST:        106.51 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.34d {+22h 25m 22s}   -8.30d {-08d 18' 06"}
MOON_DIST:       109.24 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.39, 40.49 [deg] galactic lon,lat of the burst
ECL_COORDS:      225.48,  4.96 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:27:45 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     317508,   Seg_Num: 0
GRB_RA:          224.4831d {+14h 57m 55.9s} (J2000),
                 224.5996d {+14h 58m 23.9s} (current),
                 223.8027d {+14h 55m 12.6s} (1950)
GRB_DEC:         -11.7241d {-11d 43' 26.7"} (J2000),
                 -11.7580d {-11d 45' 28.9"} (current),
                 -11.5243d {-11d 31' 27.5"} (1950)
GRB_ERROR:       -773094113.3 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       162 [cnts]
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37624.12 SOD {10:27:04.12} UT,   107.2 [sec] since BAT Trigger Time
CENTROID_X:      299.40,  raw= 299  [pixels]
CENTROID_Y:      195.22,  raw= 195  [pixels]
ROLL:            288.10 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -242.27
GRB_POS_XRT_Z:   -6.83
IMAGE_URL:       sw00317508000msxps_rw.img
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 08"}
SUN_DIST:        106.51 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.34d {+22h 25m 22s}   -8.30d {-08d 18' 07"}
MOON_DIST:       109.24 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.39, 40.49 [deg] galactic lon,lat of the burst
ECL_COORDS:      225.48,  4.96 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        WARNING: The centroided position is more than 100 rows or columns from the center of the FOV.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:29:00 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     317508,   Seg_Num: 0
GRB_RA:          224.471d {+14h 57m 53s} (J2000),
                 224.587d {+14h 58m 21s} (current),
                 223.790d {+14h 55m 10s} (1950)
GRB_DEC:         -11.712d {-11d 42' 43"} (J2000),
                 -11.746d {-11d 44' 45"} (current),
                 -11.512d {-11d 30' 43"} (1950)
GRB_DATE:        14668 TJD;   203 DOY;   08/07/21
GRB_TIME:        37516.97 SOD {10:25:16.97} UT
TRIGGER_INDEX:   155
GRB_PHI:           3.23 [deg]
GRB_THETA:        56.52 [deg]
DELTA_TIME:      7.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     142.33 [sigma]
IMAGE_SIGNIF:    10.24 [sigma]
LC_URL:          sw00317508000msb.lc
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 08"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.35d {+22h 25m 25s}   -8.30d {-08d 17' 49"}
MOON_DIST:       109.26 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.39, 40.51 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      225.46,  4.97 [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 = 128.41,-20.50 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:29:30 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.463d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.788d {-11d 47' 17"} (J2000)
POINT_ROLL:      288.102d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37632.62 SOD {10:27:12.62} UT,   115.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.107
N_STARS:         49
X_OFFSET:        848 [pixels]
Y_OFFSET:        976 [pixels]
X_MAX:           1807 [pixels]
Y_MAX:           1935 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0115.fits
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 08"}
SUN_DIST:        106.51 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.36d {+22h 25m 26s}   -8.30d {-08d 17' 42"}
MOON_DIST:       109.25 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:30:09 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.463d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.788d {-11d 47' 17"} (J2000)
POINT_ROLL:      288.102d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37632.62 SOD {10:27:12.62} UT,   115.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.107
N_STARS:         49
X_OFFSET:        848 [pixels]
Y_OFFSET:        976 [pixels]
X_MAX:           1807 [pixels]
Y_MAX:           1935 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0115.fits
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 07"}
SUN_DIST:        106.51 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.36d {+22h 25m 27s}   -8.29d {-08d 17' 33"}
MOON_DIST:       109.26 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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 21 Jul 08 10:31:14 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.463d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.788d {-11d 47' 17"} (J2000)
ROLL:            288.102d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37632.62 SOD {10:27:12.62} UT,   115.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     238328835
X_OFFSET:        1052 [pixels]
Y_OFFSET:        1300 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1212
Y_GRB_POS:       1460
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0115.fits
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 07"}
SUN_DIST:        106.51 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.37d {+22h 25m 29s}   -8.29d {-08d 17' 17"}
MOON_DIST:       109.27 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:30:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.463d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.788d {-11d 47' 17"} (J2000)
ROLL:            288.102d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37632.62 SOD {10:27:12.62} UT,   115.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     238328835
X_OFFSET:        1052 [pixels]
Y_OFFSET:        1300 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1212
Y_GRB_POS:       1460
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0115.fits
SUN_POSTN:       121.17d {+08h 04m 40s}  +20.35d {+20d 21' 07"}
SUN_DIST:        106.51 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.37d {+22h 25m 28s}   -8.29d {-08d 17' 23"}
MOON_DIST:       109.27 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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:     Mon 21 Jul 08 10:37:01 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
POINT_ROLL:      288.100d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37739.45 SOD {10:28:59.45} UT,   222.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        2.004
N_STARS:         71
X_OFFSET:        732 [pixels]
Y_OFFSET:        980 [pixels]
X_MAX:           1691 [pixels]
Y_MAX:           1939 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0222.fits
SUN_POSTN:       121.17d {+08h 04m 41s}  +20.35d {+20d 21' 04"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.42d {+22h 25m 40s}   -8.27d {-08d 15' 54"}
MOON_DIST:       109.32 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:37:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
POINT_ROLL:      288.100d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37739.45 SOD {10:28:59.45} UT,   222.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        2.004
N_STARS:         71
X_OFFSET:        732 [pixels]
Y_OFFSET:        980 [pixels]
X_MAX:           1691 [pixels]
Y_MAX:           1939 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0222.fits
SUN_POSTN:       121.17d {+08h 04m 42s}  +20.35d {+20d 21' 04"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.42d {+22h 25m 41s}   -8.26d {-08d 15' 48"}
MOON_DIST:       109.32 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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 21 Jul 08 10:38:24 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
ROLL:            288.100d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37739.45 SOD {10:28:59.45} UT,   222.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     238328942
X_OFFSET:        1052 [pixels]
Y_OFFSET:        1300 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1212
Y_GRB_POS:       1460
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0222.fits
SUN_POSTN:       121.17d {+08h 04m 42s}  +20.35d {+20d 21' 03"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.43d {+22h 25m 43s}   -8.26d {-08d 15' 34"}
MOON_DIST:       109.33 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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:     Mon 21 Jul 08 10:38:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
ROLL:            288.100d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37739.45 SOD {10:28:59.45} UT,   222.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     238328942
X_OFFSET:        1052 [pixels]
Y_OFFSET:        1300 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1212
Y_GRB_POS:       1460
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0222.fits
SUN_POSTN:       121.17d {+08h 04m 42s}  +20.35d {+20d 21' 03"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.43d {+22h 25m 43s}   -8.26d {-08d 15' 29"}
MOON_DIST:       109.33 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:41:35 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 24"} (J2000)
POINT_ROLL:      288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38372.86 SOD {10:39:32.86} UT,   855.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.057
N_STARS:         62
X_OFFSET:        732 [pixels]
Y_OFFSET:        980 [pixels]
X_MAX:           1691 [pixels]
Y_MAX:           1939 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0855.fits
SUN_POSTN:       121.18d {+08h 04m 42s}  +20.35d {+20d 21' 02"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.45d {+22h 25m 49s}   -8.25d {-08d 14' 48"}
MOON_DIST:       109.36 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:42:03 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 24"} (J2000)
POINT_ROLL:      288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38372.86 SOD {10:39:32.86} UT,   855.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.057
N_STARS:         62
X_OFFSET:        732 [pixels]
Y_OFFSET:        980 [pixels]
X_MAX:           1691 [pixels]
Y_MAX:           1939 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0855.fits
SUN_POSTN:       121.18d {+08h 04m 42s}  +20.35d {+20d 21' 01"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.46d {+22h 25m 50s}   -8.25d {-08d 14' 42"}
MOON_DIST:       109.36 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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 21 Jul 08 10:42:57 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 24"} (J2000)
ROLL:            288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38372.86 SOD {10:39:32.86} UT,   855.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     238329575
X_OFFSET:        1051 [pixels]
Y_OFFSET:        1299 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1211
Y_GRB_POS:       1459
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0855.fits
SUN_POSTN:       121.18d {+08h 04m 42s}  +20.35d {+20d 21' 01"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.47d {+22h 25m 52s}   -8.24d {-08d 14' 29"}
MOON_DIST:       109.37 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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 21 Jul 08 10:43:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 24"} (J2000)
ROLL:            288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38372.86 SOD {10:39:32.86} UT,   855.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     238329575
X_OFFSET:        1051 [pixels]
Y_OFFSET:        1299 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1211
Y_GRB_POS:       1459
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0855.fits
SUN_POSTN:       121.18d {+08h 04m 42s}  +20.35d {+20d 21' 01"}
SUN_DIST:        106.50 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.47d {+22h 25m 53s}   -8.24d {-08d 14' 22"}
MOON_DIST:       109.38 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:43:53 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     317508,   Seg_Num: 0
GRB_RA:          224.4826d {+14h 57m 55.82s} (J2000),
                 224.5991d {+14h 58m 23.79s} (current),
                 223.8022d {+14h 55m 12.52s} (1950)
GRB_DEC:         -11.7235d {-11d 43' 24.5"} (J2000),
                 -11.7574d {-11d 45' 26.7"} (current),
                 -11.5237d {-11d 31' 25.3"} (1950)
GRB_ERROR:       0.7 [arcsec radius, statistical only]
GRB_MAG:         14.60 +/- 0.10 [mag]
FILTER:          10, White
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37636.00 SOD {10:27:16.00} UT,   119.0 [sec] since BAT Trigger Time
SUN_POSTN:       121.18d {+08h 04m 43s}  +20.35d {+20d 21' 01"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.47d {+22h 25m 53s}   -8.24d {-08d 14' 15"}
MOON_DIST:       109.38 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.39, 40.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      225.48,  4.96 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN Circular #7988
F. E. Marshall (NASA/GSFC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), V. Mangano (INAF-IASFPA), P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), D. Perez (U Leicester), M. Perri (ASDC), B. Preger (ASDC), P. Romano (INAF-IASFPA), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), T. N. Ukwatta (GSFC/GWU), P. A. Ward (MSSL-UCL) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 10:25:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080721 (trigger=317508). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 224.471, -11.712 which is
```
   RA(J2000) = 14h 57m 53s
   Dec(J2000) = -11d 42' 43"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed at least 4 peaks structure with a duration of about 35 sec. The peak count rate was ~19k counts/sec (15-350 keV), at ~0 sec after the trigger, during the second peak.
The XRT began observing the field at 10:27:04.1 UT, 107.2 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 224.4899, -11.7242 which is equivalent to:
```
   RA(J2000)  = 14h 57m 55.9s
   Dec(J2000) = -11d 43' 27.3"
```
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 79 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
UVOT took a finding chart exposure of nominal 100 seconds with the White (160-650 nm) filter starting 180 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at
```
  RA(J2000)  =  14:57:55.8 = 224.48268
  DEC(J2000) = -11:43:25   = -11.72361
```
with a 1-sigma error radius of about 1.0 arc sec. The estimated white magnitude is 14.6 with a 1-sigma error of about 0.01 mag. No correction has been made for Galactic extinction.
Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:48:20 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
POINT_ROLL:      288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38478.77 SOD {10:41:18.77} UT,   961.8 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        2.062
N_STARS:         69
X_OFFSET:        732 [pixels]
Y_OFFSET:        980 [pixels]
X_MAX:           1691 [pixels]
Y_MAX:           1939 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0961.fits
SUN_POSTN:       121.18d {+08h 04m 43s}  +20.35d {+20d 20' 58"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.51d {+22h 26m 02s}   -8.22d {-08d 13' 11"}
MOON_DIST:       109.42 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 10:48:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
POINT_ROLL:      288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38478.77 SOD {10:41:18.77} UT,   961.8 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        2.062
N_STARS:         69
X_OFFSET:        732 [pixels]
Y_OFFSET:        980 [pixels]
X_MAX:           1691 [pixels]
Y_MAX:           1939 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00317508000msufc0961.fits
SUN_POSTN:       121.18d {+08h 04m 43s}  +20.35d {+20d 20' 58"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.51d {+22h 26m 03s}   -8.22d {-08d 13' 04"}
MOON_DIST:       109.42 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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 21 Jul 08 10:49:42 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
ROLL:            288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38478.77 SOD {10:41:18.77} UT,   961.8 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     238329681
X_OFFSET:        1051 [pixels]
Y_OFFSET:        1299 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1211
Y_GRB_POS:       1459
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0961.fits
SUN_POSTN:       121.18d {+08h 04m 44s}  +20.35d {+20d 20' 58"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.52d {+22h 26m 05s}   -8.21d {-08d 12' 51"}
MOON_DIST:       109.43 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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 21 Jul 08 10:50:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     317508,   Seg_Num: 0
POINT_RA:        224.464d {+14h 57m 51s} (J2000)
POINT_DEC:       -11.790d {-11d 47' 23"} (J2000)
ROLL:            288.101d
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  38478.77 SOD {10:41:18.77} UT,   961.8 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     238329681
X_OFFSET:        1051 [pixels]
Y_OFFSET:        1299 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1211
Y_GRB_POS:       1459
BINNING_INDEX:   1
IM_URL:          sw00317508000msuni0961.fits
SUN_POSTN:       121.18d {+08h 04m 44s}  +20.35d {+20d 20' 57"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.52d {+22h 26m 06s}   -8.21d {-08d 12' 45"}
MOON_DIST:       109.43 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.32, 40.45 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      225.48,  4.89 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 21 Jul 08 11:04:22 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     317508,   Seg_Num: 0
GRB_RA:          224.4899d {+14h 57m 57.5s} (J2000),
                 224.6064d {+14h 58m 25.5s} (current),
                 223.8095d {+14h 55m 14.2s} (1950)
GRB_DEC:         -11.7241d {-11d 43' 26.7"} (J2000),
                 -11.7580d {-11d 45' 28.9"} (current),
                 -11.5243d {-11d 31' 27.6"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       5.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      300.00 [sigma]
IMG_START_DATE:  14668 TJD;   203 DOY;   08/07/21
IMG_START_TIME:  37625.00 SOD {10:27:05.00} UT,   108.0 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.19 261.35 242.66
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       121.19d {+08h 04m 46s}  +20.35d {+20d 20' 50"}
SUN_DIST:        106.49 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      336.64d {+22h 26m 33s}   -8.16d {-08d 09' 20"}
MOON_DIST:       109.55 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      345.40, 40.49 [deg] galactic lon,lat of the burst
ECL_COORDS:      225.48,  4.96 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values are not valid.

GCN Circular #7989
C. Guidorzi (INAF-OAB), P. A. Evans and K. L. Page (U Leicester) report on behalf of the Swift-XRT team:
We note that the correct XRT position of GRB 080721 (Marshall et al., GCN Circ. 7988) is that given in sexagesimal coordinates, which corresponds to RA, Dec 224.48292, -11.72425 degrees (J2000; 4.7 arcsec radius, 90%) and is also consistent with the UVOT position. The XRT position given in degrees in the same circular, which has also been distributed in the XRT position notice, is not correct. We apologise for any inconvenient this may have caused.
GCN Circular #7990
T-W Chen, L-C Huang, Y-T Chen (NCU) K.Y Huang (ASIAA) and Y. Urata (Saitama U./ASIAA) on behalf of the EAFON report;
"We have been monitoring the optical afterglow of GRB080721 (Marshall et al. GCN Circ 7988) using the Lulin 1 m telescope after the twilight (~ 96 min after the burst). Based on Lulin R-band data, the optical afterglow is located at RA=14:57:55.835, Dec=-11:43:24.76 with less than 1" position error. The brightness of the optical afterglow at 98 min after the burst is R~18.1.
Further optical observation is in progress."
GCN Circular #7991
S. T. Holland, P. A. Ward (MSSL-UCL), and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT Team:
Preliminary UVOT photometry of the afterglow of GRB 080721 (Marshall, et al. 2008, GCN Circ. 7988) shows that the afterglow is strongly detected in the U band, but not in the UVW1, UVM2, or UVW2 bands at approximately 825 s after the BAT trigger. This suggests that the redshift of GRB 080721 may be greater than approximately 2.3.
GCN Circular #7992
J. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC), K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+750 sec from the recent telemetry downlink, we report further analysis of BAT GRB 080721 (trigger #317508) (Marshall, et al., GCN Circ. 7988). The BAT ground-calculated position is RA, Dec = 224.481, -11.709 deg, which is
```
   RA(J2000)  =  14h 57m 55.4s 
   Dec(J2000) = -11d 42' 33.3" 
```
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 4%.
The mask-weighted light curve shows approximately six peaks. The first starts at ~T-11 sec and peaks at ~T-7 sec. The second and third peaks are much brighter. They peak at ~T+1 and ~T+7 sec. The remaining peaks are much smaller and stretch out to ~T+370 sec. T90 (15-350 keV) is 16.2 +- 4.5 sec (estimated error including systematics).
The time-averaged spectrum from T-2.6 to T+25.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.11 +- 0.08. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T-0.16 sec in the 15-150 keV band is 20.9 +- 1.8 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/317508/BA/
GCN Circular #7993
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 2722 s of XRT Photon Counting mode data and 6 UVOT images for GRB 080721, 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 = 224.48231, -11.72363 which is equivalent to:
```
RA (J2000): 14h 57m 55.75s
Dec (J2000): -11d 43' 25.1"
```
with an uncertainty of 1.5 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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method.
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #7994
C. Guidorzi, F. Pasotti (INAF-OAB), F. E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team:
We have analysed the first three orbits of Swift-XRT data obtained for GRB 080721 (Marshall et al., GCN Circ. 7988), covering 1.3 ks and 2.8 ks of Windowed Timing (WT) and Photon Counting (PC) modes data, respectively, between 113 s and 10.6 ks after the trigger. Notably, the whole first orbit data are taken in WT mode. The UVOT-enhanced XRT position was given by Osborne et al. in GCN Circ. 7993.
The light-curve can be modelled by an initial power law with index 0.75 +/- 0.04 followed by a constant rate step from ~260 to 330 s, after which the curve resumes a power-law decay with an index of 1.06 +/- 0.01 up to 10.6 ks (chisq/dof = 1292/1207).
A spectrum extracted from the first orbit of data can be modelled with an absorbed power-law, with Gamma = 1.90 +/- 0.02 and NH = (1.10 +/- 0.05)x1e21 cm^-2, in excess of the Galactic column in this direction of 6.9e20 cm^-2. We found no evidence for spectral evolution during this time interval. The observed (unabsorbed) flux over this time interval (113-1370 s post-trigger) is 2.2e-9 (2.7e-9) erg cm^-2 s^-1.
If the light-curve continues to decay with alpha ~1.06, the count rate 24 hours after the burst is estimated to be 0.23 count s^-1, which corresponds to an observed flux of 9.6e-12 erg cm^-2 s^-1.
This is an official product of the Swift-XRT team.
GCN Circular #7995
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team report:
The bright GRB 080721 (Swift-BAT trigger #317508: Marshall et al., GCN 7988, Cummings et al., GCN 7992) triggered Konus-Wind at T0=37510.927 s UT (10:25:10.927).
The burst light shows multipeaked structure with a duration of ~30 s.
As observed by Konus-Wind the burst had a fluence of 8.38(-0.60, +0.62)x10^-5 erg/cm2, and a 64-ms peak flux measured from T0+9.648 s of (1.96 +/- 0.31)x10^-5 erg/cm2/s (both in the 20 keV - 5 MeV energy range).
The time-integrated spectrum of the burst (from T0 to T0+23.808 s) is well fitted (in the 20 keV - 5 MeV range) by GRBM (Band) model for which: the low-energy photon index is alpha = -0.933(-0.084, +0.106), the high energy photon index beta = -2.43(-0.42, +0.24), the peak energy Ep = 485(-59, +67) keV (chi2 = 60.6/76 dof).
All the quoted errors are at the 90% confidence level.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080721_T37510/
GCN Circular #7996
P. Ward (MSSL-UCL), S. T. Holland (CRESST/USRA/GSFC) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift Ultra-Violet/Optical Telescope (UVOT) started observing GRB 080703 (Marshall et al., GCN 7988) ~118 seconds after the trigger.
A fading afterglow is found in the UVOT White, V, B and U filters. The refined Swift/UVOT position of the optical afterglow candidate is:
```
  RA(J2000)  = 14:57:55.855 =  224.48273
  DEC(J2000) = -11:43:24.54 = -11.723483
```
with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence). The following table gives the measured magnitudes:
```
Filter  T_start T_stop Exp     Mag

white  118    217   99.8   14.58 +/- 0.00
white  858    957   99.8   16.94 +/- 0.03
white 5173   5372  199.8   19.12 +/- 0.08
white 6609   6808  199.8   19.43 +/- 0.11
v      225    624  399.7   14.98 +/- 0.01
v      964   1363  399.8   16.47 +/- 0.03
v     5583   5782  199.8   18.27 +/- 0.17
v     7020   7157  137.7   18.40 +/- 0.23
b      704   6603  409.4   16.56 +/- 0.12
u      680   6398  439.3   16.58 +/- 0.12
uvw1   655   6192  439.2   > 18.01
uvm2   631   5987  245.3   > 17.58
uvw2   734   7014  419.4   > 18.03
```
Using the measured magnitudes we find a power law decay index of -1.2 and -1.01 in the white and V filters respectively. The strong detection in the U band, but not in the UVW1, UVM2, or UVW2 bands gives an estimated photometric redshift in the range of 2.3 < z < 2.8.
The values quoted above are in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627). No correction has been made for the expected extinction corresponding to E(B-V) of 0.100 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #7997
P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-OAR), G. Adreuzzi, G. Tessicini (INAF-TNG), L. A. Antonelli, F. Fiore (INAF-OAR), D. Fugazza, C. Guidorzi (INAF-OAB) and G. Chincarini (Univ. Bicocca) report, on behalf of the CIBO collaboration:
Following the Swift detection of GRB080721 (Marshall et al., GCN 7988), we triggered observations with the DOLORES low resolution spectrograph, mounted at the Italian TNG telescope located in the Canary Islands (Spain). The observations were performed using the LR-B grism. We took a 1800 s spectrum starting around Jul 21 at 21:30 UT (about 11.0 hours after the burst) and covering the range 300-780 nm with a resolution of R ~ 600.
A preliminary analysis of the spectra shows a broad absorption feature at lambda_obs ~ 440 nm (based on a preliminary wavelength calibration). Interpreting this feature as Ly-alpha we infer a redshift z = 2.602, in agreement with the UVOT photometric redshift estimate (Holland et al., GCN 7991; Ward et al. GCN 7996). At this redshift we can detect also (rest frame) other absorption features like: CII (133.4 nm), SiIV doublet (139.3-140.2 nm), SiII (152.6 nm), CIV doublet (154.8-155.0 nm).
We are very grateful for the excellent support of the TNG staff.
GCN Circular #7998
P. Jakobsson (U. Hertfordshire), D. Malesani, P. M. Vreeswijk, J. P. U. Fynbo, B. Milvang-Jensen (DARK/NBI), A. de Ugarte Postigo (ESO), B. Nordstrom (NBI), E. Stonkute (ITPA, Vilnius) and P. Sorensen (NOT) report on behalf of a larger collaboration:
We observed the optical afterglow of GRB 080721 (Marshall et al., GCN 7988; Chen et al., GCN 7990) with ALFOSC on the Nordic Optical Telescope at La Palma. The afterglow is well detected in a single 300 s exposure starting on 21.875 July 2008 (10.6 hr after the GRB). Comparison with several USNO-B1 stars (R1 magnitudes) yields R = 20.0 +/- 0.2, where most of the error comes from the calibration. Using the R-band magnitude provided by Chen et al., the inferred decay index is alpha ~ 0.9.
Low resolution spectra (3 x 30 min) were also obtained. The combined spectrum displays a strong absorption feature around 4350 A, with the flux dropping substantially blueward of this feature. Associating it with Ly-alpha gives a redshift of z ~ 2.6 for the burst. We find several other absorption features, including O I, Si II, C II, Si IV, C IV, Fe II and Al II, corresponding to a redshift of z = 2.591 +/- 0.001, consistent with the redshift reported by D'Avanzo et al. (GCN 7997) and the UVOT photometric redshift (Ward et al., GCN 7996).
GCN Circular #7999
L-C Huang, T-W Chen, Y-T Chen (NCU) K.Y Huang (ASIAA) and Y. Urata (Saitama U./ASIAA) on behalf of the EAFON report;
"We made further optical observations for the optical afterglow of GRB 080721 (Marshall et al., GCN 7988; Chen et al., GCN 7990) using the Lulin 1 m telescope. The single R-band image with 300 sec exposure shows the afterglow well with R=21.3 (mid term of the exposure is 26.19 hours after the burst). Comparison with our previous report (Chen et al. GCN 7990), the temporal decay index is ~1.0. This is consistent with the result reported by Jakobsson et al. (GCN 7998).
GCN Circular #8011
Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward optically bright GRB 080721 (GCN 7988) at a frequency of 8.46 GHz on 2008 July 24.15 UT. The GRB radio afterglow is undetected and the peak radio flux at the UVOT afterglow position (GCN 7988) is 93 =B1 48 uJy.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Report 156.1
GCN_Report 156.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_156_1.pdf by F.E. Marshall at NASA/GSFC titled: "Final results on Swift GRB 080721"
0812.2490 from 12 Dec 2008
Starling: Constraining the energy budget of GRB 080721
Abstract: We follow the bright, highly energetic afterglow of Swift-discovered GRB 080721 out to 36 days or 3e6 s since the trigger in the optical and X-ray bands. We do not detect a break in the late-time light curve inferring a limit on the opening angle of theta_j >= 7.22 deg and setting tight constraints on the total energy budget of the burst of E_gamma >= 9.88e51 erg within the fireball model. To obey the fireball model closure relations the GRB jet must be expanding into a homogeneous surrounding medium. The energy constraint we derive can be used as observational input for models of the progenitors of long gamma-ray bursts: we discuss how such high collimation-corrected energies could be accommodated with certain parameters of the standard massive star core-collapse models. We can, however, most probably rule out a magnetar progenitor for this GRB which would require 100% efficiency to reach the observed total energy.

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Jochen Greiner, last update: 16-Feb-2009 [Disclaimer]