Gamma-ray Burst 230802A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:50:40 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1182085,   Seg_Num: 0
GRB_RA:           76.221d {+05h 04m 53s} (J2000),
                  76.568d {+05h 06m 16s} (current),
                  75.484d {+05h 01m 56s} (1950)
GRB_DEC:         +19.570d {+19d 34' 10"} (J2000),
                 +19.600d {+19d 36' 01"} (current),
                 +19.501d {+19d 30' 05"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4133 [cnts]    Image_Peak=437 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       15639 [cnts]
BKG_TIME:        24608.24 SOD {06:50:08.24} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20158 TJD;   214 DOY;   23/08/02
GRB_TIME:        24626.16 SOD {06:50:26.16} UT
GRB_PHI:         147.87 [deg]
GRB_THETA:        11.13 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     44.77 [sigma]
IMAGE_SIGNIF:    16.03 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +4  +0  +0 -60  +0 
SUN_POSTN:       132.20d {+08h 48m 47s}  +17.80d {+17d 48' 16"}
SUN_DIST:         52.49 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      320.94d {+21h 23m 45s}  -20.25d {-20d 15' 02"}
MOON_DIST:       119.90 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.70,-12.90 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       77.01, -3.25 [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 = 1.96,18.14 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(4.0<100sec) coincident with the FERMI_GBM event (trignum=712651827).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:51:00 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     712651827
GRB_RA:           68.517d {+04h 34m 04s} (J2000),
                  68.846d {+04h 35m 23s} (current),
                  67.819d {+04h 31m 17s} (1950)
GRB_DEC:         +12.467d {+12d 28' 00"} (J2000),
                 +12.514d {+12d 30' 52"} (current),
                 +12.363d {+12d 21' 47"} (1950)
GRB_ERROR:       9.12 [deg radius, statistical plus systematic]
GRB_INTEN:       276 [cnts/sec]
DATA_SIGNIF:     14.10 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20158 TJD;   214 DOY;   23/08/02
GRB_TIME:        24622.23 SOD {06:50:22.23} UT
GRB_PHI:          57.00 [deg]
GRB_THETA:       105.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.62
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      67%  Distant Particles
2nd_MOST_LIKELY:  28%  GRB
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       132.20d {+08h 48m 47s}  +17.80d {+17d 48' 15"}
SUN_DIST:         61.11 [deg]   Sun_angle= 4.2 [hr] (West of Sun)
MOON_POSTN:      320.94d {+21h 23m 46s}  -20.25d {-20d 14' 58"}
MOON_DIST:       110.89 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      184.13,-23.07 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       68.75, -9.40 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230802285/quicklook/glg_lc_medres34_bn230802285.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 108.27,-25.10 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(4.0<100sec) coincident with the SWIFT_BAT event (trignum=1182085).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:50:52 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      45
TRIGGER_NUM:     712651827
GRB_RA:           72.667d {+04h 50m 40s} (J2000),
                  73.003d {+04h 52m 01s} (current),
                  71.954d {+04h 47m 49s} (1950)
GRB_DEC:         +15.333d {+15d 19' 60"} (J2000),
                 +15.372d {+15d 22' 19"} (current),
                 +15.249d {+15d 14' 55"} (1950)
GRB_ERROR:       20.22 [deg radius, statistical plus systematic]
GRB_INTEN:       120 [cnts/sec]
DATA_SIGNIF:     6.20 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20158 TJD;   214 DOY;   23/08/02
GRB_TIME:        24622.23 SOD {06:50:22.23} UT
GRB_PHI:          52.00 [deg]
GRB_THETA:       105.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.65
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      52%  Distant Particles
2nd_MOST_LIKELY:  42%  GRB
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       132.20d {+08h 48m 47s}  +17.80d {+17d 48' 15"}
SUN_DIST:         56.55 [deg]   Sun_angle= 3.9 [hr] (West of Sun)
MOON_POSTN:      320.94d {+21h 23m 45s}  -20.25d {-20d 15' 00"}
MOON_DIST:       115.57 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      184.23,-18.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       73.17, -7.10 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230802285/quicklook/glg_lc_medres34_bn230802285.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 108.27,-25.10 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(4.0<100sec) coincident with the SWIFT_BAT event (trignum=1182085).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:51:53 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1182085,   Seg_Num: 0
GRB_RA:           76.2390d {+05h 04m 57.36s} (J2000),
                  76.5866d {+05h 06m 20.77s} (current),
                  75.5027d {+05h 02m 00.65s} (1950)
GRB_DEC:         +19.5612d {+19d 33' 40.3"} (J2000),
                 +19.5920d {+19d 35' 31.3"} (current),
                 +19.4932d {+19d 29' 35.6"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.25e-09 [erg/cm2/sec]
GRB_SIGNIF:      6.16 [sigma]
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24690.30 SOD {06:51:30.30} UT,   64.1 [sec] since BAT Trigger Time
TAM[0-3]:        327.64 237.12 261.82 243.15
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       132.20d {+08h 48m 47s}  +17.80d {+17d 48' 15"}
SUN_DIST:         52.47 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      320.95d {+21h 23m 48s}  -20.25d {-20d 14' 47"}
MOON_DIST:       119.90 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.72,-12.89 [deg] galactic lon,lat of the burst
ECL_COORDS:       77.03, -3.26 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.14 arcmin from the BAT position.

GCN NOTICE


TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:52:04 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1182085,   Seg_Num: 0
GRB_RA:           76.2390d {+05h 04m 57.3s} (J2000),
                  76.5866d {+05h 06m 20.7s} (current),
                  75.5027d {+05h 02m 00.6s} (1950)
GRB_DEC:         +19.5612d {+19d 33' 40.3"} (J2000),
                 +19.5920d {+19d 35' 31.3"} (current),
                 +19.4932d {+19d 29' 35.6"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       38 [cnts]
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24690.30 SOD {06:51:30.30} UT,   64.1 [sec] since BAT Trigger Time
CENTROID_X:      291.46,  raw= 291  [pixels]
CENTROID_Y:      278.94,  raw= 279  [pixels]
ROLL:            82.10 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -45.15
GRB_POS_XRT_Z:   -37.56
IMAGE_URL:       sw01182085000msxps_rw.img
SUN_POSTN:       132.20d {+08h 48m 47s}  +17.80d {+17d 48' 15"}
SUN_DIST:         52.47 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      320.95d {+21h 23m 48s}  -20.25d {-20d 14' 45"}
MOON_DIST:       119.90 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.72,-12.89 [deg] galactic lon,lat of the burst
ECL_COORDS:       77.03, -3.26 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:52:06 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1182085,   Seg_Num: 0
GRB_RA:           76.2390d {+05h 04m 57.3s} (J2000),
                  76.5866d {+05h 06m 20.7s} (current),
                  75.5027d {+05h 02m 00.6s} (1950)
GRB_DEC:         +19.5612d {+19d 33' 40.3"} (J2000),
                 +19.5920d {+19d 35' 31.3"} (current),
                 +19.4932d {+19d 29' 35.6"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       38 [cnts]
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24690.30 SOD {06:51:30.30} UT,   64.1 [sec] since BAT Trigger Time
CENTROID_X:      291.46,  raw= 291  [pixels]
CENTROID_Y:      278.94,  raw= 279  [pixels]
ROLL:            82.10 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -45.15
GRB_POS_XRT_Z:   -37.56
IMAGE_URL:       sw01182085000msxps_rw.img
SUN_POSTN:       132.20d {+08h 48m 47s}  +17.80d {+17d 48' 15"}
SUN_DIST:         52.47 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      320.95d {+21h 23m 49s}  -20.25d {-20d 14' 44"}
MOON_DIST:       119.90 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.72,-12.89 [deg] galactic lon,lat of the burst
ECL_COORDS:       77.03, -3.26 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:54:03 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1182085,   Seg_Num: 0
GRB_RA:           76.221d {+05h 04m 53s} (J2000),
                  76.568d {+05h 06m 16s} (current),
                  75.484d {+05h 01m 56s} (1950)
GRB_DEC:         +19.570d {+19d 34' 10"} (J2000),
                 +19.600d {+19d 36' 01"} (current),
                 +19.501d {+19d 30' 05"} (1950)
GRB_DATE:        20158 TJD;   214 DOY;   23/08/02
GRB_TIME:        24626.16 SOD {06:50:26.16} UT
TRIGGER_INDEX:   146
GRB_PHI:         147.87 [deg]
GRB_THETA:        11.13 [deg]
DELTA_TIME:      -31.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     44.77 [sigma]
IMAGE_SIGNIF:    16.03 [sigma]
LC_URL:          sw01182085000msb.lc
SUN_POSTN:       132.20d {+08h 48m 48s}  +17.80d {+17d 48' 13"}
SUN_DIST:         52.49 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      320.97d {+21h 23m 54s}  -20.24d {-20d 14' 19"}
MOON_DIST:       119.86 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.70,-12.90 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       77.01, -3.25 [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 = 1.96,18.14 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:57:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1182085,   Seg_Num: 0
POINT_RA:         76.226d {+05h 04m 54s} (J2000)
POINT_DEC:       +19.572d {+19d 34' 21"} (J2000)
POINT_ROLL:      82.103d
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24699.60 SOD {06:51:39.60} UT,   73.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.637
N_STARS:         48
X_OFFSET:        440 [pixels]
Y_OFFSET:        584 [pixels]
X_MAX:           1399 [pixels]
Y_MAX:           1543 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw01182085000msufc0073.fits
SUN_POSTN:       132.20d {+08h 48m 48s}  +17.80d {+17d 48' 11"}
SUN_DIST:         52.49 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      321.00d {+21h 24m 01s}  -20.23d {-20d 13' 41"}
MOON_DIST:       119.84 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.70,-12.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       77.01, -3.25 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 06:57:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1182085,   Seg_Num: 0
POINT_RA:         76.226d {+05h 04m 54s} (J2000)
POINT_DEC:       +19.572d {+19d 34' 21"} (J2000)
POINT_ROLL:      82.103d
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24699.60 SOD {06:51:39.60} UT,   73.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.637
N_STARS:         48
X_OFFSET:        440 [pixels]
Y_OFFSET:        584 [pixels]
X_MAX:           1399 [pixels]
Y_MAX:           1543 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw01182085000msufc0073.fits
SUN_POSTN:       132.20d {+08h 48m 48s}  +17.80d {+17d 48' 11"}
SUN_DIST:         52.49 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      321.01d {+21h 24m 02s}  -20.23d {-20d 13' 38"}
MOON_DIST:       119.83 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.70,-12.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       77.01, -3.25 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 07:00:23 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1182085,   Seg_Num: 0
POINT_RA:         76.226d {+05h 04m 54s} (J2000)
POINT_DEC:       +19.572d {+19d 34' 21"} (J2000)
ROLL:            82.103d
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24699.60 SOD {06:51:39.60} UT,   73.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     712651931
X_OFFSET:        896 [pixels]
Y_OFFSET:        914 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1056
Y_GRB_POS:       1074
BINNING_INDEX:   1
IM_URL:          sw01182085000msuni0105.fits
SUN_POSTN:       132.20d {+08h 48m 49s}  +17.80d {+17d 48' 09"}
SUN_DIST:         52.49 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      321.04d {+21h 24m 10s}  -20.22d {-20d 12' 59"}
MOON_DIST:       119.80 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.70,-12.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       77.01, -3.25 [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:     Wed 02 Aug 23 07:00:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1182085,   Seg_Num: 0
POINT_RA:         76.226d {+05h 04m 54s} (J2000)
POINT_DEC:       +19.572d {+19d 34' 21"} (J2000)
ROLL:            82.103d
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  24699.60 SOD {06:51:39.60} UT,   73.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     712651931
X_OFFSET:        896 [pixels]
Y_OFFSET:        914 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1056
Y_GRB_POS:       1074
BINNING_INDEX:   1
IM_URL:          sw01182085000msuni0105.fits
SUN_POSTN:       132.20d {+08h 48m 49s}  +17.80d {+17d 48' 09"}
SUN_DIST:         52.49 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      321.04d {+21h 24m 10s}  -20.22d {-20d 12' 57"}
MOON_DIST:       119.80 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.70,-12.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       77.01, -3.25 [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 Circular #34313
N. J. Klingler (GSFC/UMBC/CRESSTII), V. D'Elia (SSDC & INAF-OAR), P. A. Evans (U Leicester), J. A. Kennea (PSU), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), A. Melandri (INAF-OAR), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 06:50:26 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 230802A (trigger=1182085). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 76.221, +19.570 which is
```
   RA(J2000) = 05h 04m 53s
   Dec(J2000) = +19d 34' 10"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a wide pulse structure with a duration of about 60 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 06:51:30.3 UT, 64.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 76.23952, 19.56147 which is equivalent to:
```
   RA(J2000)  = 05h 04m 57.48s
   Dec(J2000) = +19d 33' 41.3"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 69 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 https://www.swift.ac.uk/sper. No spectrum from the promptly downlinked event data is yet available to determine the column density.
The initial flux in the 2.5 s image was 1.25e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 73 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 0.614.
Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 02 Aug 23 07:31:09 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1182085,   Seg_Num: 0
GRB_RA:           76.2399d {+05h 04m 57.57s} (J2000),
                  76.5875d {+05h 06m 20.99s} (current),
                  75.5036d {+05h 02m 00.87s} (1950)
GRB_DEC:         +19.5615d {+19d 33' 41.3"} (J2000),
                 +19.5923d {+19d 35' 32.4"} (current),
                 +19.4935d {+19d 29' 36.7"} (1950)
GRB_ERROR:       3.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20158 TJD;   214 DOY;   23/08/02
IMG_START_TIME:  25067.00 SOD {06:57:47.00} UT,   440.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       132.22d {+08h 48m 54s}  +17.80d {+17d 47' 50"}
SUN_DIST:         52.50 [deg]   Sun_angle= 3.7 [hr] (West of Sun)
MOON_POSTN:      321.37d {+21h 25m 28s}  -20.11d {-20d 06' 26"}
MOON_DIST:       119.49 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      182.72,-12.89 [deg] galactic lon,lat of the burst
ECL_COORDS:       77.03, -3.26 [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:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #34317
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1180 s of XRT Photon Counting mode data and 1 UVOT images for GRB 230802A, 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 = 76.23985, +19.56066 which is equivalent to:
```
RA (J2000): 05h 04m 57.56s
Dec (J2000): +19d 33' 38.4"
```
with an uncertainty of 2.0 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 #34318
A.P. Beardmore (U. Leicester), B. Sbarufatti (INAF-OAB), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), J. D. Gropp (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester) and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 7.9 ks of XRT data for GRB 230802A, from 52 s to 40.1 ks after the BAT trigger. The data comprise 386 s in Windowed Timing (WT) mode (the first 10 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode.
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.4 (+/-0.4). At T+345 s the decay steepens to an alpha of 2.5 (+0.4, -0.3) before breaking again at T+1364 s to a final decay with index alpha=1.26 (+0.16, -0.30).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.02 (+/-0.04). The best-fitting absorption column is 6.5 (+/-0.5) x 10^21 cm^-2, in excess of the Galactic value of 3.4 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.66 (+0.22, -0.21) and a best-fitting absorption column of 4.5 (+1.5, -1.1) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.9 x 10^-11 (6.5 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     4.5 (+1.5, -1.1) x 10^21 cm^-2
Galactic foreground: 3.4 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.66 (+0.22, -0.21)
```
If the light curve continues to decay with a power-law decay index of 1.26, the count rate at T+24 hours will be 1.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.2 x 10^-14 (9.7 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01182085.
This circular is an official product of the Swift-XRT team.
GCN Circular #34320
E. Fernandez-Garcia, Y.-D. Hu, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar (UMA) and I. M. Carrasco-Garcia (SMA) and I. H. Park (SKKU), on behalf of a larger collaboration, report:
Following the detection of GRB 230802A by Swift (Klingler et al. GCNC 34313), the BOOTES-5/JGT 0.6m robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically observed the GRB location starting on Aug. 02, 11:41 UT (~ 4.9 h after trigger). No new optical source is detected on the co-added image (13 x 60 s, clear filter) within the enhanced Swift/XRT error region (Goad et al. GCNC 34317) down to 19.7 mag, which is consistent with the limit reported by UVOT (Klingler et al. GCNC 34313).
We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support.
GCN Circular #34321
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University)
MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 230802A ( N. J. Klingler et al., GCN 34313) errorbox 65651 sec after notice time and 65669 sec after trigger time at 2023-08-03 01:04:55 UT, with upper limit up to 15.3 mag. Observations started at twilight. The observations began at zenith distance = 65 deg. The sun altitude is -13.8 deg.
The galactic latitude b = -12 deg., longitude l = 183 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2248891
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   65759 |      MASTER-Tavrida |   C |   180 | 15.3 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #34329
GRB 230802A: Swift/UVOT Upper Limits
S. J. LaPorte (PSU) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230802A 73 s after the BAT trigger (Klingler et al., GCN Circ. 34313). No optical afterglow consistent with the XRT position (Evans et al., GCN Circ. 34317) 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            73          223          147         >20.0
u_FC               286          535          246         >19.5
white               73         1186          353         >20.5
v                  615         1581          117         >18.4
b                  541         1506           97         >19.2
u                  286         5048          492         >19.7
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.614 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #34333
S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),T. Sakamoto (AGU), M. Stamatikos (OSU) (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 230802A (trigger #1182085) (Klingler et al., GCN Circ. 34313). The BAT ground-calculated position is RA, Dec = 76.232, 19.552 deg which is
```
   RA(J2000)  =  05h 04m 55.6s
   Dec(J2000) = +19d 33' 06.3"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 99%.
The BAT light curve shows a complex structure with a duration of ~ 200 sec. T90 (15-350 keV) is 175.62 +- 18.26 sec (estimated error including systematics).
The time-averaged spectrum from T-6.04 to T+230.70 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.60 +- 0.07. The fluence in the 15-150 keV band is 5.0 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.60 sec in the 15-150 keV band is 2.3 +- 0.2 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/1182085/BA/
GCN Circular #34334
C. de Barra (UCD), J.Mangan (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 06:50:22.23 UT on 2 August 2023, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 230802A (trigger 712651827 / 230802285), which was also detected by Swift BAT (N. J. Klingler et al. 2023, GCN 34313). The Fermi GBM on-ground location is consistent with the Swift BAT position.
The angle from the Fermi LAT boresight at the GBM trigger time is 107 degrees.
The GBM light curve consists of a single peak with a duration (T90) of about 38 s (50-300 keV)The time-averaged spectrum from -14.3s to 26.6 s is best fit by a simple power law function with index -1.7 +/- 0.02.
The event fluence (10-1000 keV) in this time interval is (1.3 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.4 s in the 10-1000 keV band is 5.6 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

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Jochen Greiner, last update: 04-Aug-2023 [Disclaimer]