Gamma-ray Burst 170822A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:13:26 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     768939,   Seg_Num: 0
GRB_RA:           94.382d {+06h 17m 32s} (J2000),
                  94.748d {+06h 18m 59s} (current),
                  93.344d {+06h 13m 23s} (1950)
GRB_DEC:         +55.019d {+55d 01' 07"} (J2000),
                 +55.011d {+55d 00' 39"} (current),
                 +55.037d {+55d 02' 14"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       15078 [cnts]    Image_Peak=578 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   300     E_range: 25-100 keV
BKG_INTEN:       153151 [cnts]
BKG_TIME:        33052.43 SOD {09:10:52.43} UT
BKG_DUR:         40 [sec]
GRB_DATE:        17987 TJD;   234 DOY;   17/08/22
GRB_TIME:        33111.05 SOD {09:11:51.05} UT
GRB_PHI:         -61.60 [deg]
GRB_THETA:        41.81 [deg]
SOLN_STATUS:     0x203
RATE_SIGNIF:     28.67 [sigma]
IMAGE_SIGNIF:    15.48 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +2  +4  +0  +0 -46  +0 
SUN_POSTN:       151.59d {+10h 06m 21s}  +11.65d {+11d 39' 15"}
SUN_DIST:         61.79 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.54d {+10h 38m 09s}   +9.98d {+09d 58' 52"}
MOON_DIST:        67.51 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.38, 17.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       92.95, 31.62 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        Since the foreground interval count rate is less than the bkg interval (SAA exit), this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 286.60,1.42 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:14:58 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     768939,   Seg_Num: 0
GRB_RA:           94.3828d {+06h 17m 31.87s} (J2000),
                  94.7485d {+06h 19m 00.34s} (current),
                  93.3456d {+06h 13m 22.94s} (1950)
GRB_DEC:         +54.9886d {+54d 59' 18.9"} (J2000),
                 +54.9808d {+54d 58' 50.8"} (current),
                 +55.0074d {+55d 00' 26.5"} (1950)
GRB_ERROR:       5.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.28e-09 [erg/cm2/sec]
GRB_SIGNIF:      5.65 [sigma]
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33274.28 SOD {09:14:34.28} UT,   163.2 [sec] since BAT Trigger Time
TAM[0-3]:        327.64 237.24 261.59 243.47
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 13"}
SUN_DIST:         61.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.55d {+10h 38m 12s}   +9.98d {+09d 58' 37"}
MOON_DIST:        67.51 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.41, 17.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       92.95, 31.59 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.79 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:15:08 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     768939,   Seg_Num: 0
GRB_RA:           94.3828d {+06h 17m 31.8s} (J2000),
                  94.7485d {+06h 19m 00.3s} (current),
                  93.3456d {+06h 13m 22.9s} (1950)
GRB_DEC:         +54.9886d {+54d 59' 18.9"} (J2000),
                 +54.9808d {+54d 58' 50.8"} (current),
                 +55.0074d {+55d 00' 26.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       32 [cnts]
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33274.28 SOD {09:14:34.28} UT,   163.2 [sec] since BAT Trigger Time
CENTROID_X:      276.25,  raw= 276  [pixels]
CENTROID_Y:      231.48,  raw= 231  [pixels]
ROLL:            111.15 [deg]
GAIN:            8
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -157.73
GRB_POS_XRT_Z:   -71.05
IMAGE_URL:       sw00768939000msxps_rw.img
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 13"}
SUN_DIST:         61.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.55d {+10h 38m 13s}   +9.98d {+09d 58' 35"}
MOON_DIST:        67.51 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.41, 17.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       92.95, 31.59 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:15:12 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     768939,   Seg_Num: 0
GRB_RA:           94.3828d {+06h 17m 31.8s} (J2000),
                  94.7485d {+06h 19m 00.3s} (current),
                  93.3456d {+06h 13m 22.9s} (1950)
GRB_DEC:         +54.9886d {+54d 59' 18.9"} (J2000),
                 +54.9808d {+54d 58' 50.8"} (current),
                 +55.0074d {+55d 00' 26.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       32 [cnts]
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33274.28 SOD {09:14:34.28} UT,   163.2 [sec] since BAT Trigger Time
CENTROID_X:      276.25,  raw= 276  [pixels]
CENTROID_Y:      231.48,  raw= 231  [pixels]
ROLL:            111.15 [deg]
GAIN:            8
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -157.73
GRB_POS_XRT_Z:   -71.05
IMAGE_URL:       sw00768939000msxps_rw.img
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 13"}
SUN_DIST:         61.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.55d {+10h 38m 13s}   +9.98d {+09d 58' 34"}
MOON_DIST:        67.51 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.41, 17.35 [deg] galactic lon,lat of the burst
ECL_COORDS:       92.95, 31.59 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:16:15 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     768939,   Seg_Num: 0
GRB_RA:           94.382d {+06h 17m 32s} (J2000),
                  94.748d {+06h 18m 59s} (current),
                  93.344d {+06h 13m 23s} (1950)
GRB_DEC:         +55.019d {+55d 01' 07"} (J2000),
                 +55.011d {+55d 00' 39"} (current),
                 +55.037d {+55d 02' 14"} (1950)
GRB_DATE:        17987 TJD;   234 DOY;   17/08/22
GRB_TIME:        33111.05 SOD {09:11:51.05} UT
TRIGGER_INDEX:   300
GRB_PHI:         -61.60 [deg]
GRB_THETA:        41.81 [deg]
DELTA_TIME:      58.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x203
RATE_SIGNIF:     28.67 [sigma]
IMAGE_SIGNIF:    15.48 [sigma]
LC_URL:          sw00768939000msb.lc
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 12"}
SUN_DIST:         61.79 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.56d {+10h 38m 15s}   +9.97d {+09d 58' 24"}
MOON_DIST:        67.53 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.38, 17.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       92.95, 31.62 [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:        Since the foreground interval count rate is less than the bkg interval (SAA exit), this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 286.60,1.42 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:17:35 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.379d {+06h 17m 31s} (J2000)
POINT_DEC:       +55.036d {+55d 02' 09"} (J2000)
POINT_ROLL:      111.154d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33282.37 SOD {09:14:42.37} UT,   171.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.601
N_STARS:         96
X_OFFSET:        608 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1567 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00768939000msufc0171.fits
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 11"}
SUN_DIST:         61.80 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.58d {+10h 38m 18s}   +9.97d {+09d 58' 10"}
MOON_DIST:        67.55 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.95, 31.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:17:49 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.379d {+06h 17m 31s} (J2000)
POINT_DEC:       +55.036d {+55d 02' 09"} (J2000)
POINT_ROLL:      111.154d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33282.37 SOD {09:14:42.37} UT,   171.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.601
N_STARS:         96
X_OFFSET:        608 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1567 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00768939000msufc0171.fits
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 11"}
SUN_DIST:         61.80 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.58d {+10h 38m 19s}   +9.97d {+09d 58' 08"}
MOON_DIST:        67.55 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.95, 31.64 [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 22 Aug 17 09:19:11 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.379d {+06h 17m 31s} (J2000)
POINT_DEC:       +55.036d {+55d 02' 09"} (J2000)
ROLL:            111.154d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33282.37 SOD {09:14:42.37} UT,   171.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     525086101
X_OFFSET:        1092 [pixels]
Y_OFFSET:        1084 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1252
Y_GRB_POS:       1244
BINNING_INDEX:   1
IM_URL:          sw00768939000msuni0191.fits
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 10"}
SUN_DIST:         61.80 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.59d {+10h 38m 22s}   +9.97d {+09d 57' 54"}
MOON_DIST:        67.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.95, 31.64 [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 22 Aug 17 09:19:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.379d {+06h 17m 31s} (J2000)
POINT_DEC:       +55.036d {+55d 02' 09"} (J2000)
ROLL:            111.154d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33282.37 SOD {09:14:42.37} UT,   171.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     525086101
X_OFFSET:        1092 [pixels]
Y_OFFSET:        1084 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1252
Y_GRB_POS:       1244
BINNING_INDEX:   1
IM_URL:          sw00768939000msuni0191.fits
SUN_POSTN:       151.59d {+10h 06m 22s}  +11.65d {+11d 39' 10"}
SUN_DIST:         61.80 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.59d {+10h 38m 22s}   +9.96d {+09d 57' 53"}
MOON_DIST:        67.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.95, 31.64 [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 22 Aug 17 09:31:27 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.376d {+06h 17m 30s} (J2000)
POINT_DEC:       +55.038d {+55d 02' 19"} (J2000)
POINT_ROLL:      111.151d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33987.80 SOD {09:26:27.80} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.180
N_STARS:         190
X_OFFSET:        532 [pixels]
Y_OFFSET:        524 [pixels]
X_MAX:           1971 [pixels]
Y_MAX:           1963 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00768939000msufc0876.fits
SUN_POSTN:       151.60d {+10h 06m 24s}  +11.65d {+11d 38' 59"}
SUN_DIST:         61.81 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.71d {+10h 38m 50s}   +9.93d {+09d 55' 50"}
MOON_DIST:        67.65 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.94, 31.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:31:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.376d {+06h 17m 30s} (J2000)
POINT_DEC:       +55.038d {+55d 02' 19"} (J2000)
POINT_ROLL:      111.151d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33987.80 SOD {09:26:27.80} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.180
N_STARS:         190
X_OFFSET:        532 [pixels]
Y_OFFSET:        524 [pixels]
X_MAX:           1971 [pixels]
Y_MAX:           1963 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00768939000msufc0876.fits
SUN_POSTN:       151.60d {+10h 06m 24s}  +11.65d {+11d 38' 59"}
SUN_DIST:         61.81 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.71d {+10h 38m 50s}   +9.93d {+09d 55' 48"}
MOON_DIST:        67.65 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.94, 31.64 [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 22 Aug 17 09:32:02 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     768939,   Seg_Num: 0
GRB_RA:           94.3868d {+06h 17m 32.83s} (J2000),
                  94.7526d {+06h 19m 00.62s} (current),
                  93.3494d {+06h 13m 23.85s} (1950)
GRB_DEC:         +55.0039d {+55d 00' 14.0"} (J2000),
                 +54.9961d {+54d 59' 45.8"} (current),
                 +55.0227d {+55d 01' 21.6"} (1950)
GRB_ERROR:       2.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33329.00 SOD {09:15:29.00} UT,   217.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       151.60d {+10h 06m 24s}  +11.65d {+11d 38' 59"}
SUN_DIST:         61.79 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.71d {+10h 38m 51s}   +9.93d {+09d 55' 44"}
MOON_DIST:        67.64 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.40, 17.36 [deg] galactic lon,lat of the burst
ECL_COORDS:       92.95, 31.61 [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 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Aug 17 09:32:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.376d {+06h 17m 30s} (J2000)
POINT_DEC:       +55.038d {+55d 02' 19"} (J2000)
ROLL:            111.151d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33987.80 SOD {09:26:27.80} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     525086807
X_OFFSET:        1091 [pixels]
Y_OFFSET:        1083 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1251
Y_GRB_POS:       1243
BINNING_INDEX:   1
IM_URL:          sw00768939000msuni0896.fits
SUN_POSTN:       151.60d {+10h 06m 24s}  +11.65d {+11d 38' 58"}
SUN_DIST:         61.81 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.72d {+10h 38m 53s}   +9.93d {+09d 55' 36"}
MOON_DIST:        67.66 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.94, 31.64 [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:     Tue 22 Aug 17 09:32:59 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     768939,   Seg_Num: 0
POINT_RA:         94.376d {+06h 17m 30s} (J2000)
POINT_DEC:       +55.038d {+55d 02' 19"} (J2000)
ROLL:            111.151d
IMG_START_DATE:  17987 TJD;   234 DOY;   17/08/22
IMG_START_TIME:  33987.80 SOD {09:26:27.80} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     525086807
X_OFFSET:        1091 [pixels]
Y_OFFSET:        1083 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1251
Y_GRB_POS:       1243
BINNING_INDEX:   1
IM_URL:          sw00768939000msuni0896.fits
SUN_POSTN:       151.60d {+10h 06m 24s}  +11.65d {+11d 38' 58"}
SUN_DIST:         61.81 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      159.72d {+10h 38m 53s}   +9.93d {+09d 55' 35"}
MOON_DIST:        67.66 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      159.36, 17.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.94, 31.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #21640
A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), K. L. Page (U Leicester), T. Sakamoto (AGU), B. Sbarufatti (PSU), R. L. C. Starling (U Leicester) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team:
At 09:11:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170822A (trigger=768939). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 94.382, +55.019 which is
```
   RA(J2000) = 06h 17m 32s
   Dec(J2000) = +55d 01' 07"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 70 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 09:14:34.2 UT, 163.2 seconds after the BAT trigger. The position determined from promptly downlinked data differs significantly from the on-board position, suggesting that the XRT may have centroided on a cosmic ray; the initial XRT position notice should be treated with caution. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 94.3869, 55.0040 which is equivalent to:
```
   RA(J2000)  = 06h 17m 32.86s
   Dec(J2000) = +55d 00' 14.5"
```
with an uncertainty of 2.0 arcseconds (radius, 90% containment). This location is 54 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.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.91 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.6 (+2.37/-2.09) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 171 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 expected extinction corresponding to E(B-V) of 0.17.
Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it). 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 #21642
J. C. Tello, A. J. Castro-Tirado, R. Cunniffe, B.-B. Zhang, Y. Hu and A. Gonz=E1lez-Rodr=EDguez (IAA-CSIC), I. Carrasco (Univ. de Malaga), D. Hiriart, W. H. Lee (UNAM), S. Jeong and I. H. Park (SKKU) and P. Kubanek (Inst. of Physics, CZ) on behalf of a larger collaboration, report:
The 60 cm BOOTES-5/JGT at Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir (M=E9xico) automatically responded in 7s (and 102s after the alert) to the Swift trigger of GRB 170822A (Melandri et al., GCN 21640). The first unfiltered images (10 s exposures) were obtained at 09:13:38 UT (mid exposure). At the position of the Swift X-ray afterglow, we detect the likely optical afterglow at a magnitude of 18.3 (comparing to USNO-B1.0) and fading by 0.8 mag at 09:14:00 UT. The preliminary position is RA (J2000) =3D 6:17:32.89, Dec (J2000) =3D +55:00:16.13 (+/- 0".5). Further observations are being carried out. Spectroscopic observations are encouraged.
We thank the staff at Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir for its excellent support.
GCN Circular #21643
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 2226 s of XRT Photon Counting mode data and 2 UVOT images for GRB 170822A, 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 = 94.38672, +55.00424 which is equivalent to:
```
RA (J2000): 06h 17m 32.81s
Dec (J2000): +55d 00' 15.3"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #21647
P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester) and A. Melandri report on behalf of the Swift-XRT team:
We have analysed 8.8 ks of XRT data for GRB 170822A (Melandri et al. GCN Circ. 21640), from 153 s to 19.2 ks after the BAT trigger. The data comprise 32 s in Windowed Timing (WT) mode (the first 7 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 21643).
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=1.29 (+0.27, -0.23). At T+522 s the decay flattens to an alpha of -0.77 (+0.28, -0.35). The light curve breaks again at T+1393 s to a decay with alpha=0.81 (+0.09, -0.11), before a final break at T+6591 s s after which the decay index is 1.89 (+0.37, -0.14).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.84 (+/-0.08). The best-fitting absorption column is 3.5 (+/-0.4) x 10^21 cm^-2, in excess of the Galactic value of 1.9 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x 10^-11 (5.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     3.5 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 1.9 x 10^21 cm^-2
Excess significance: 6.6 sigma
Photon index:	     1.84 (+/-0.08)
```
If the light curve continues to decay with a power-law decay index of 1.89, the count rate at T+24 hours will be 6.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.9 x 10^-13 (4.1 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/00768939.
This circular is an official product of the Swift-XRT team.
GCN Circular #21649
S.W.K. Emery (UCL-MSSL) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170822A 171 s after the BAT trigger (Melandri et al., GCN Circ. 21640). No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 21643) and the optical position (Tello et al., GCN Circ. 21642) 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        171          321          148         >20.4
white              529         1894          284         >21.3
v                      406         1936          165         >19.2
b                      504         1870          156         >20.2
u                      480         1845          156         >19.8
uvw1              455         1820          155         >19.7
uvm2              604         1101           39         >18.1
uvw2              381         1921          175         >19.9
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.17 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #21651
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL), 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 170822A (trigger #768939) (Melandri et al., GCN Circ. 21640). The BAT ground-calculated position is RA, Dec = 94.375, 55.000 deg which is
```
  RA(J2000)  =  06h 17m 29.9s
  Dec(J2000) = +54d 59' 59.0"
```
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 12%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~ T-15 s and ends at ~T+60 s. T90 (15-350 keV) is 64 +- 16 sec (estimated error including systematics).
The time-averaged spectrum from T-15.62 to T+64.38 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.80 +- 0.09. The fluence in the 15-150 keV band is 6.4 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+7.88 sec in the 15-150 keV band is 4.2 +- 0.7 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/768939/BA/
GCN Circular #21652
K. L. Murata, Y. Saito, R. Itoh, Y. Tachibana, T. Yoshii, S. Harita, K. Morita, T. Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 170822A (Melandri et al., GCN Circular #21640) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2017-08-22 16:27:38.15 UT . We did not find any new point source within enhanced XRT circle (Evans et al., GCN Circular #21643) in all three bands. We obtained following limits for the magnitudes.
```
T0+[hour]    MID-UT      T-EXP[sec]         g'              Rc
       Ic
-------------------------------------------------------------------------------------------------------
~7.21        16:48:33.09      2280          >20.8        >20.1
 >18.9
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used GSC2.3 catalog for flux calibration.
GCN Circular #21654
E. Mazaeva (IKI), R. Inasaridze (AbAO), A. Pozanenko (IKI), A. Volnova (IKI), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 170822A (Melandri et al., GCN 21640)) with AS-32 (0.7m) telescope of Abastumani Observatory starting on August, 22 (UT) 22:43:12. We obtained several unfiltered images of the field. Within enhanced XRT error circle (Beardmore et al., GCN 21643) we do not detect the afterglow candidate (Tello et al, GCN 21642). Preliminary photometry of the field is following
```
Date        UT start  t-T0     Filter Exp.   OT   Err UpLim (3 sigma)
                       (mid, days)     (s)

2017-08-22 22:43:12  0.58255   CR     32*60  n/d  n/d 22.2
```
Photometry is based on nearby USNO-B1.0 stars R2 magnitudes
```
USNO-B.1_id  R2
1450-0165651 15.44
1450-0165657 15.54
1450-0165669 16.19
1450-0165558 16.58
1450-0165549 15.60
1450-0165573 15.28
1449-0164981 16.05
```
A finding chart can be found at http://grb.rssi.ru/GRB170822A/GRB170822A_AAO_170822+Bootes-OT.png
GCN Circular #21655
Alan M. Watson (UNAM), Nat Butler (ASU), 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 170822A (Melandri et al., GCN Circ. 21640) w= ith 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 2017/08 23.44 to 2017/08 23.48 UTC (25.45 to 26.38 hours after the BAT trigger), obtaining a total of 0.69 hours exposure in the r and i bands and 0.30 hours exposure in the Z, Y, J, and H bands.
For a source within the Swift-XRT error circle, in comparison with the US= NO-B1=20 and 2MASS catalogs, we obtain the following upper limits (3-sigma):
```
 r	> 23.37
 i	> 22.87
 Z	> 21.99
 Y	> 21.56
 J	> 21.28
 H	> 20.82
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
The bright but rapidly-fading optical transient reported by Tello et al. (GCN Circ. 21642) is not seen in our images.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #21679
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline on behalf of the Konus-Wind team, report:
The long-duration, soft-spectrum GRB 170822A (Swift-BAT detection: Melandri et al., GCN Circ. 21640) triggered Konus-Wind at T0=33111.022 s UT (09:11:51.022).
The burst light curve shows a multipeaked structure which starts at ~T0-10.5 s and has a total duration of ~62 s. The emission is seen up to ~1 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170822_T33111/
As observed by Konus-Wind, the burst had a fluence of 8.57(-0.76,+0.88)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.266 s, of 1.66(-0.60,+0.60)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+57.6 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.20(-0.38,+0.48) and Ep = 70(-12,+12) keV (chi2 = 57/62 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.4 (chi2 = 55/61 dof).
The spectrum near the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: with alpha = -1.17(-0.26,+0.30) and Ep = 90(-11,+13) keV (chi2 = 51/61 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.8 (chi2 = 51/60 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #21702
V. Sharma (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed clear detection of short GRB 170822A (Swift detection: Melandri A. et al, GCN Circ. 21640) in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 09:11:52.0 UT, around 1 s after the Swift/BAT trigger. The measured peak count rate is 163.1 counts/s above the background in combined data of four quadrants, with a total 369 counts. The local mean background count rate was 399.0 counts/s. Using cumulative rates, we measure a T90 of 62.3 s.
It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular #21947
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 170822A (Melandri et al., GCN 21640) as part of the 4pisky program, and subsequent follow up observations were obtained up to 30 days post-burst. Our observations at 15 GHz on 2017 Aug 22.42, Aug 25.34, Aug 26.34, Aug 30.37, Sep 03.28 and Sep 20.26 (UT) do not reveal any radio source at the XRT location (Beardmore et al., GCN 21643), with 3sigma upper limits of 165 uJy, 132 uJy, 138 uJy, 210 uJy, 210 uJy and 138 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: 01-Oct-2017 [Disclaimer]