Gamma-ray Burst 210722A

(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:     Thu 22 Jul 21 20:55:00 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.023d {+01h 48m 06s} (J2000),
                  27.293d {+01h 49m 10s} (current),
                  26.397d {+01h 45m 35s} (1950)
GRB_DEC:          -6.354d {-06d 21' 14"} (J2000),
                  -6.248d {-06d 14' 50"} (current),
                  -6.603d {-06d 36' 10"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2608 [cnts]    Image_Peak=145 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   149     E_range: 25-100 keV
BKG_INTEN:       14528 [cnts]
BKG_TIME:        75268.58 SOD {20:54:28.58} UT
BKG_DUR:         8 [sec]
GRB_DATE:        19417 TJD;   203 DOY;   21/07/22
GRB_TIME:        75282.02 SOD {20:54:42.02} UT
GRB_PHI:          -0.50 [deg]
GRB_THETA:        41.52 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.11 [sigma]
IMAGE_SIGNIF:    9.11 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +0 +12  +0 
SUN_POSTN:       122.45d {+08h 09m 49s}  +20.09d {+20d 05' 30"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.05d {+19h 00m 13s}  -25.66d {-25d 39' 50"}
MOON_DIST:        98.21 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.24 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       22.70,-16.33 [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 = 134.63,-19.66 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:56:57 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      45
TRIGGER_NUM:     648680085
GRB_RA:           28.733d {+01h 54m 56s} (J2000),
                  29.010d {+01h 56m 02s} (current),
                  28.092d {+01h 52m 22s} (1950)
GRB_DEC:          +0.467d {+00d 28' 00"} (J2000),
                  +0.572d {+00d 34' 18"} (current),
                  +0.222d {+00d 13' 19"} (1950)
GRB_ERROR:       18.70 [deg radius, statistical plus systematic]
GRB_INTEN:       114 [cnts/sec]
DATA_SIGNIF:     6.30 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        19417 TJD;   203 DOY;   21/07/22
GRB_TIME:        75280.87 SOD {20:54:40.87} UT
GRB_PHI:         265.98 [deg]
GRB_THETA:       105.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      1.28
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       0,0,0, 0,1,0, 0,0,1, 0,0,0, 0,0,
SUN_POSTN:       122.46d {+08h 09m 49s}  +20.09d {+20d 05' 29"}
SUN_DIST:         93.04 [deg]   Sun_angle= 6.2 [hr] (West of Sun)
MOON_POSTN:      285.07d {+19h 00m 18s}  -25.66d {-25d 39' 48"}
MOON_DIST:       102.79 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      154.46,-58.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       26.87,-10.59 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210722871/quicklook/glg_lc_medres34_bn210722871.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 40.35,17.68 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the SWIFT_BAT event (trignum=1061223).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:58:02 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     648680085
GRB_RA:           28.100d {+01h 52m 24s} (J2000),
                  28.371d {+01h 53m 29s} (current),
                  27.472d {+01h 49m 53s} (1950)
GRB_DEC:          -5.317d {-05d 19' 00"} (J2000),
                  -5.211d {-05d 12' 38"} (current),
                  -5.563d {-05d 33' 46"} (1950)
GRB_ERROR:       10.80 [deg radius, statistical plus systematic]
GRB_INTEN:       129 [cnts/sec]
DATA_SIGNIF:     10.00 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19417 TJD;   203 DOY;   21/07/22
GRB_TIME:        75280.87 SOD {20:54:40.87} UT
GRB_PHI:         263.00 [deg]
GRB_THETA:       110.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.26
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       0,0,0, 0,1,0, 0,0,1, 0,0,0, 0,0,
SUN_POSTN:       122.46d {+08h 09m 49s}  +20.09d {+20d 05' 28"}
SUN_DIST:         95.61 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.09d {+19h 00m 21s}  -25.66d {-25d 39' 47"}
MOON_DIST:        99.61 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      159.29,-63.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       24.13,-15.76 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210722871/quicklook/glg_lc_medres34_bn210722871.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 40.35,17.68 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the SWIFT_BAT event (trignum=1061223).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:56:43 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.0285d {+01h 48m 06.8s} (J2000),
                  27.2987d {+01h 49m 11.6s} (current),
                  26.4022d {+01h 45m 36.5s} (1950)
GRB_DEC:          -6.3452d {-06d 20' 42.7"} (J2000),
                  -6.2384d {-06d 14' 18.3"} (current),
                  -6.5939d {-06d 35' 37.9"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       101 [cnts]
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75366.84 SOD {20:56:06.84} UT,   84.8 [sec] since BAT Trigger Time
CENTROID_X:      295.37,  raw= 295  [pixels]
CENTROID_Y:      312.46,  raw= 312  [pixels]
ROLL:            70.50 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   33.86
GRB_POS_XRT_Z:   -28.34
IMAGE_URL:       sw01061223000msxps_rw.img
SUN_POSTN:       122.46d {+08h 09m 49s}  +20.09d {+20d 05' 29"}
SUN_DIST:         96.96 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.07d {+19h 00m 17s}  -25.66d {-25d 39' 48"}
MOON_DIST:        98.20 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.23 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.70,-16.32 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:56:41 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.0285d {+01h 48m 06.8s} (J2000),
                  27.2987d {+01h 49m 11.6s} (current),
                  26.4022d {+01h 45m 36.5s} (1950)
GRB_DEC:          -6.3452d {-06d 20' 42.7"} (J2000),
                  -6.2384d {-06d 14' 18.3"} (current),
                  -6.5939d {-06d 35' 37.9"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       101 [cnts]
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75366.84 SOD {20:56:06.84} UT,   84.8 [sec] since BAT Trigger Time
CENTROID_X:      295.37,  raw= 295  [pixels]
CENTROID_Y:      312.46,  raw= 312  [pixels]
ROLL:            70.50 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   33.86
GRB_POS_XRT_Z:   -28.34
IMAGE_URL:       sw01061223000msxps_rw.img
SUN_POSTN:       122.46d {+08h 09m 49s}  +20.09d {+20d 05' 29"}
SUN_DIST:         96.96 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.07d {+19h 00m 17s}  -25.66d {-25d 39' 48"}
MOON_DIST:        98.20 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.23 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.70,-16.32 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:56:30 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.0285d {+01h 48m 06.84s} (J2000),
                  27.2987d {+01h 49m 11.67s} (current),
                  26.4022d {+01h 45m 36.52s} (1950)
GRB_DEC:          -6.3452d {-06d 20' 42.7"} (J2000),
                  -6.2384d {-06d 14' 18.3"} (current),
                  -6.5939d {-06d 35' 37.9"} (1950)
GRB_ERROR:       5.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.90e-09 [erg/cm2/sec]
GRB_SIGNIF:      10.04 [sigma]
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75366.84 SOD {20:56:06.84} UT,   84.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.64 237.15 261.60 243.52
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       122.46d {+08h 09m 49s}  +20.09d {+20d 05' 29"}
SUN_DIST:         96.96 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.07d {+19h 00m 17s}  -25.66d {-25d 39' 49"}
MOON_DIST:        98.21 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.23 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.70,-16.32 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.62 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:58:55 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.023d {+01h 48m 06s} (J2000),
                  27.293d {+01h 49m 10s} (current),
                  26.397d {+01h 45m 35s} (1950)
GRB_DEC:          -6.354d {-06d 21' 14"} (J2000),
                  -6.248d {-06d 14' 50"} (current),
                  -6.603d {-06d 36' 10"} (1950)
GRB_DATE:        19417 TJD;   203 DOY;   21/07/22
GRB_TIME:        75282.02 SOD {20:54:42.02} UT
TRIGGER_INDEX:   149
GRB_PHI:          -0.50 [deg]
GRB_THETA:        41.52 [deg]
DELTA_TIME:      -63.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.11 [sigma]
IMAGE_SIGNIF:    9.11 [sigma]
LC_URL:          sw01061223000msb.lc
SUN_POSTN:       122.46d {+08h 09m 50s}  +20.09d {+20d 05' 28"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.10d {+19h 00m 23s}  -25.66d {-25d 39' 46"}
MOON_DIST:        98.17 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.24 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       22.70,-16.33 [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 = 134.63,-19.66 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:59:04 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.025d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.357d {-06d 21' 26"} (J2000)
POINT_ROLL:      70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75376.22 SOD {20:56:16.22} UT,   94.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.553
N_STARS:         20
X_OFFSET:        480 [pixels]
Y_OFFSET:        552 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1511 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw01061223000msufc0094.fits
SUN_POSTN:       122.46d {+08h 09m 50s}  +20.09d {+20d 05' 28"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.10d {+19h 00m 24s}  -25.66d {-25d 39' 46"}
MOON_DIST:        98.17 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 20:59:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.025d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.357d {-06d 21' 26"} (J2000)
POINT_ROLL:      70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75376.22 SOD {20:56:16.22} UT,   94.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.553
N_STARS:         20
X_OFFSET:        480 [pixels]
Y_OFFSET:        552 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1511 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw01061223000msufc0094.fits
SUN_POSTN:       122.46d {+08h 09m 50s}  +20.09d {+20d 05' 28"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.10d {+19h 00m 25s}  -25.66d {-25d 39' 45"}
MOON_DIST:        98.17 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:07:03 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
POINT_ROLL:      70.504d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75589.59 SOD {20:59:49.59} UT,   307.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.812
N_STARS:         13
X_OFFSET:        503 [pixels]
Y_OFFSET:        483 [pixels]
X_MAX:           1462 [pixels]
Y_MAX:           1442 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw01061223000msufc0307.fits
SUN_POSTN:       122.46d {+08h 09m 51s}  +20.09d {+20d 05' 24"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.19d {+19h 00m 45s}  -25.66d {-25d 39' 36"}
MOON_DIST:        98.09 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 21:07:10 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
POINT_ROLL:      70.504d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75589.59 SOD {20:59:49.59} UT,   307.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.812
N_STARS:         13
X_OFFSET:        503 [pixels]
Y_OFFSET:        483 [pixels]
X_MAX:           1462 [pixels]
Y_MAX:           1442 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw01061223000msufc0307.fits
SUN_POSTN:       122.46d {+08h 09m 51s}  +20.09d {+20d 05' 24"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.19d {+19h 00m 45s}  -25.66d {-25d 39' 36"}
MOON_DIST:        98.09 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:08:25 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
ROLL:            70.504d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75589.59 SOD {20:59:49.59} UT,   307.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     648680417
X_OFFSET:        823 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       983
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw01061223000msuni0335.fits
SUN_POSTN:       122.46d {+08h 09m 51s}  +20.09d {+20d 05' 23"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.20d {+19h 00m 49s}  -25.66d {-25d 39' 35"}
MOON_DIST:        98.08 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:08:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
ROLL:            70.504d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75589.59 SOD {20:59:49.59} UT,   307.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     648680417
X_OFFSET:        823 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       983
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw01061223000msuni0335.fits
SUN_POSTN:       122.46d {+08h 09m 51s}  +20.09d {+20d 05' 23"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.21d {+19h 00m 49s}  -25.66d {-25d 39' 34"}
MOON_DIST:        98.08 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.43,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:14:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
POINT_ROLL:      70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  76142.07 SOD {21:09:02.07} UT,   860.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.925
N_STARS:         27
X_OFFSET:        263 [pixels]
Y_OFFSET:        243 [pixels]
X_MAX:           1702 [pixels]
Y_MAX:           1682 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw01061223000msufc0860.fits
SUN_POSTN:       122.47d {+08h 09m 52s}  +20.09d {+20d 05' 20"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.27d {+19h 01m 04s}  -25.66d {-25d 39' 28"}
MOON_DIST:        98.02 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #30475
P. D'Avanzo (INAF-OAB), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), M. J. Moss (GWU), D. M. Palmer (LANL) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
At 20:54:42 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210722A (trigger=1061223). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 27.023, -6.354 which is
```
   RA(J2000) = 01h 48m 06s
   Dec(J2000) = -06d 21' 14"
```
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 30 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger.
Using promptly downlinked XRT data we find an uncatalogued X-ray source located at RA, Dec 27.028, -6.345 which is equivalent to:
```
   RA(J2000)  = +01h 48m 06.84
   Dec(J2000) = -06d 20' 42.7"
```
with an uncertainty of 5.0 arcseconds (radius, 90% containment).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 94 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
RA(J2000) = 01:48:07.27 = 27.03028
DEC(J2000) = -06:20:49.8 = -6.34718
```
with a 90%-confidence error radius of about 0.74 arc sec. This position is 9.6 arc sec. from the center of the XRT error circle. The estimated magnitude is 14.37 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.027.
Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT 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/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 21:14:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
POINT_ROLL:      70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  76142.07 SOD {21:09:02.07} UT,   860.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.925
N_STARS:         27
X_OFFSET:        263 [pixels]
Y_OFFSET:        243 [pixels]
X_MAX:           1702 [pixels]
Y_MAX:           1682 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw01061223000msufc0860.fits
SUN_POSTN:       122.47d {+08h 09m 52s}  +20.09d {+20d 05' 20"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.27d {+19h 01m 05s}  -25.66d {-25d 39' 27"}
MOON_DIST:        98.02 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:14:29 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.0303d {+01h 48m 07.27s} (J2000),
                  27.3005d {+01h 49m 12.11s} (current),
                  26.4040d {+01h 45m 36.95s} (1950)
GRB_DEC:          -6.3475d {-06d 20' 51.0"} (J2000),
                  -6.2407d {-06d 14' 26.6"} (current),
                  -6.5962d {-06d 35' 46.2"} (1950)
GRB_ERROR:       1.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75669.00 SOD {21:01:09.00} UT,   387.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       122.47d {+08h 09m 52s}  +20.09d {+20d 05' 20"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.27d {+19h 01m 05s}  -25.66d {-25d 39' 27"}
MOON_DIST:        98.03 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.23 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.71,-16.33 [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 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 21:16:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
ROLL:            70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  76142.07 SOD {21:09:02.07} UT,   860.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648680969
X_OFFSET:        822 [pixels]
Y_OFFSET:        802 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       982
Y_GRB_POS:       962
BINNING_INDEX:   1
IM_URL:          sw01061223000msuni0888.fits
SUN_POSTN:       122.47d {+08h 09m 52s}  +20.09d {+20d 05' 19"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.29d {+19h 01m 09s}  -25.66d {-25d 39' 25"}
MOON_DIST:        98.00 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:16:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.023d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.354d {-06d 21' 15"} (J2000)
ROLL:            70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  76142.07 SOD {21:09:02.07} UT,   860.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648680969
X_OFFSET:        822 [pixels]
Y_OFFSET:        802 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       982
Y_GRB_POS:       962
BINNING_INDEX:   1
IM_URL:          sw01061223000msuni0888.fits
SUN_POSTN:       122.47d {+08h 09m 53s}  +20.09d {+20d 05' 19"}
SUN_DIST:         96.98 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.29d {+19h 01m 10s}  -25.66d {-25d 39' 25"}
MOON_DIST:        98.00 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.24 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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 #30476
Z.P. Zhu (NAOC, HUST), S.Y. Fu, D. Xu, X. Liu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 210722A (D'Avanzo et al., GCN 30475) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained a series of 40 s, 60 s, 90 s frames in the Sloan r-band, starting at 20:56:45 UT on 2021-07-22, i.e., 123 s after the BAT trigger, among which part of the frames are useless due to the cloudy weather.
An uncatalogued optical transient is detected at the Swift/UVOT position (D'Avanzo et al., GCN 30475) with varying brightness, and thus confirms it as the optical afterglow of the burst. Preliminary analysis of the beginning photometry is as follows:
```
Tmid-T0(sec)  Mag    MagErr
143               14.33    0.01
361               13.94    0.01
452               14.01    0.01
```
All magnitudes are calibrated with the nearby PS1 field.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Jul 21 21:00:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.025d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.357d {-06d 21' 26"} (J2000)
ROLL:            70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75376.22 SOD {20:56:16.22} UT,   94.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648680203
X_OFFSET:        823 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       983
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw01061223000msuni0122.fits
SUN_POSTN:       122.46d {+08h 09m 50s}  +20.09d {+20d 05' 27"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.11d {+19h 00m 28s}  -25.66d {-25d 39' 44"}
MOON_DIST:        98.16 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:00:51 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1061223,   Seg_Num: 0
POINT_RA:         27.025d {+01h 48m 06s} (J2000)
POINT_DEC:        -6.357d {-06d 21' 26"} (J2000)
ROLL:            70.505d
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75376.22 SOD {20:56:16.22} UT,   94.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648680203
X_OFFSET:        823 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       983
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw01061223000msuni0122.fits
SUN_POSTN:       122.46d {+08h 09m 50s}  +20.09d {+20d 05' 27"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.12d {+19h 00m 28s}  -25.66d {-25d 39' 44"}
MOON_DIST:        98.15 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.70,-16.33 [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:     Thu 22 Jul 21 21:02:31 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     1061223,   Seg_Num: 0
GRB_RA:           27.0302d {+01h 48m 07.24s} (J2000),
                  27.3004d {+01h 49m 12.08s} (current),
                  26.4039d {+01h 45m 36.93s} (1950)
GRB_DEC:          -6.3471d {-06d 20' 49.5"} (J2000),
                  -6.2403d {-06d 14' 25.1"} (current),
                  -6.5958d {-06d 35' 44.8"} (1950)
GRB_ERROR:       0.7 [arcsec radius, statistical only]
GRB_MAG:         14.36 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  19417 TJD;   203 DOY;   21/07/22
IMG_START_TIME:  75373.00 SOD {20:56:13.00} UT,   91.0 [sec] since BAT Trigger Time
SUN_POSTN:       122.46d {+08h 09m 50s}  +20.09d {+20d 05' 26"}
SUN_DIST:         96.97 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      285.14d {+19h 00m 33s}  -25.66d {-25d 39' 42"}
MOON_DIST:        98.15 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      158.44,-65.23 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       22.71,-16.33 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The UVOT position is 9.0 arcsec from the XRT position.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN Circular #30478
N. Pankov (HSE, IKI), M. Krugov (FAI), A. Pozanenko (IKI), V. Kim (FAI, Pulkovo Observatory), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of GRB 210722A (D'Avanzo et al., GCN 30475) with AZT-20 telescope of Assy-Turgen observatory starting on 2021-07-22 (UT) 21:42:07. We obtained 30 frames in r' - filter before a twilight.
We clearly detect the bright optical afterglow (D'Avanzo et al., GCN 30475; Zhu et al., GCN 30476) in coordinates of 01:48:07.27 -06:20:50.00 with accuracy of 0.1 arcsec in both coordinates. The coordinates are coincides with UVOT coordinates (D'Avanzo et al., GCN 30475)
Preliminary photometry of the optical afterglow in the first image of 60 s exposure is following
```
Date       UT start  t-T0       Exp.    Filter  OT    Err.  UL(3sigma)
                    (mid, days)  (s)             (AB)

2021-07-22 21:42:07 0.03293     1*60    r'      16.20 0.03  21.1
```
The photometry is based on the nearby PS1 stars.
GCN Circular #30480
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (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, O.Ershova (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (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 210722A ( P. D'Avanzo et al., GCN 30475) errorbox 11033 sec after notice time and 11204 sec after trigger time at 2021-07-23 00:01:26 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 68 deg. The sun altitude is -19.1 deg.
The galactic latitude b = -65 deg., longitude l = 159 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1667717
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   11294 |      MASTER-Tavrida |   C |   180 | 17.6 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #30481
H. Kumar(IITB), S. Joharle (Fergusson College), J. Stanzin (IAO), V. Bhalerao(IITB), G. C. Anupama(IIA), S. Barway(IIA) report on behalf of the GIT team:
We observed GRB 210722A detected by Swift Burst Alert Telescope (P. D'Avanzo et al., GCN #30475) and optical afterglow detected by P. D'Avanzo et al., GCN #30475; Z.P. Zhu et al., GCN #30476; N. Pankov et al., GCN #30477; with 0.7m GROWTH-India Telescope (GIT). We obtained multiple exposures in the g', r' filters. The image depth was shallower than usual due to weather conditions. We clearly detected the afterglow in our images at R.A.= 1:48:07.29, DEC.= -6:20:49.85, which agrees with the swift UVOT position (GCN #30475). The photometric results follow as:
------------------------------------------------------------------------
T_start - T0 (days) | Exposure (sec) | Filter | Magnitude (AB)| Notes |
------------------------------------------------------------------------
0.014938 | 100 | g' | 15.95 +/- 0.23 | Low significance detection
0.012057 | 100 | r' | 15.11 +/- 0.08 |
0.032546 | 4x100 | r' | 16.34 +/- 0.08 | Stacked image
0.050742 | 100 | r' | 16.81 +/- 0.19 |
0.053035 | 100 | r' | 16.88 +/- 0.07 |
------------------------------------------------------------------------
Based on our observations, we found that the GRB is decaying with a power-law index of 1.14 +/- 0.03 in r' band. Our observations are in agreement with magnitudes reported by Z.P. Zhu et al., GCN #30476, and N. Pankov et al., GCN #30477. The magnitudes are calibrated against PanSTARRS (Flewelling et al., 2018) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
GCN Circular #30482
M. H. Siegel (PSU) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210722A 94 s after the BAT trigger (D'Avanzo et al., GCN Circ. 30475). A source consistent with the XRT position is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
  RA  (J2000) =  01:48:07.28 =  27.03033 (deg.)
  Dec (J2000) = -06:20:49.7  =  -6.34713 (deg.)
```
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               94          244          147         14.31 +/- 0.02
v                  637          656           19         14.52 +/- 0.06
b                  563          583           20         14.65 +/- 0.04
u                  308          557          246         13.68 +/- 0.02
w1                 686          705           20         14.08 +/- 0.06
w2                4908         4971           62         17.08 +/- 0.14
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.027 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #30483
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto) and P. D'Avanzo report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 210722A (D'Avanzo et al. GCN Circ. 30475), from 91 s to 47.1 ks after the BAT trigger. The data comprise 294 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. Using 3301 s of PC mode data and 8 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 27.03023, -6.34758 which is equivalent to:
```
RA (J2000): 01h 48m 07.26s
Dec(J2000): -06d 20' 51.3"
```
with an uncertainty of 2.0 arcsec (radius, 90% confidence).
The late-time light curve (from T0+4.5 ks) can be modelled with a power-law decay with a decay index of alpha=1.31 (+0.10, -0.09).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.20 (+/-0.05). The best-fitting absorption column is 4.2 (+1.0, -0.9) x 10^20 cm^-2, in excess of the Galactic value of 2.2 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.84 (+0.11, -0.10) and a best-fitting absorption column of 3.5 (+2.4, -1.2) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11 (3.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     3.5 (+2.4, -1.2) x 10^20 cm^-2
Galactic foreground: 2.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.84 (+0.11, -0.10)
```
If the light curve continues to decay with a power-law decay index of 1.31, the count rate at T+24 hours will be 0.013 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.4 x 10^-13 (4.8 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/01061223.
This circular is an official product of the Swift-XRT team.
GCN Circular #30484
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes�s Gonz�lez (UNAM), Carlos Rom�n-Z��iga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:
We observed the field of GRB 210722A (D'Avanzo, et al., GCN 30475) with the Reionization and Transients Infrared Camera (RATIR) on the 1.5m Harold Johnson Telescope at the Observatorio Astron�mico Nacional on Sierra San Pedro M�rtir from 2021/07 23.40 to 2021/07 23.48 UTC (12.43 to 14.36 hours after the BAT trigger), obtaining a total of 1.22 hours exposure in the r and i bands.
In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following detections of the optical afterglow:
```
  r = 19.41 +/- 0.05
  i = 19.35 +/- 0.04
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron�mico Nacional in San Pedro M�rtir.
GCN Circular #30487
C. C. Thoene (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D. A. Kann, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), J. P. U Fynbo (DAWN/NBI), L. Izzo (DARK/NBI), N. R. Tanvir (U. Leicester) and N. Castro (GTC) report:
We obtained spectroscopy of the afterglow of GRB 210722A (D’Avanzo et al. GCN #30475, Page et al. GCN #30483, Zhu et al. GCN #30476) with OSIRIS mounted on the 10.4 m GTC telescope at the Roque de los Muchachos observatory (La Palma, Spain). Observations started at 05:02:09 UT with a mid-time of 05:17:30 UT (8.38 hr after the burst) and consisted of 2x900s spectra taken with grism R1000B, which covers the spectral range between 3700 and 7800 AA. We also obtained an acquisition image of 60s in r'-band at 04:58:25 UT. Observing conditions were rather bad with a seeing of 1.7 arcsec and taken during morning twilight.
We detect several weak absorption lines, consistent with the MgII doublet, FeII 2344, 2374, 2383, 2587 and 2600 at a common redshift of z=1.145. The lines are in the weakest 1.7% of the average GRB absorption line strength (de Ugarte Postigo et al. 2012, A&A 548, 11). The detection of the afterglow in all UVOT filters (Siegel et al. GCN #30482) is consistent with this redshift.
The acquisition image shows the afterglow to be r’ = 18.92 +/- 0.03 compared to 7 SDSS field stars.
GCN Circular #30488
N. Pankov (IKI, HSE), A. Zhornichenko (KIAM), A. Pozanenko (IKI), V. Agletdinov (KIAM), M. Krugov (FAI), V. Kim (FAI), S. Belkin (IKI), Sh. Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN:
We observed the field of GRB 210722A (D'Avanzo et al., GCN 30475) with Kitab-ISON RC-36 telescope in Clear filter. Observation started on July, 22 (UT) 21:31:44 and ended on July, 22 (UT) 23:20:06. We clearly detect the bright optical afterglow (D'Avanzo et al., GCN 30475; Zhu et al., GCN 30476; Pankov et al., GCN 30478; Lipunov et al., GCN 30480; Kumar et al., GCN 30481; Siegel et al., GCN 30421; Butler et al., GCN 30484). Preliminary photometry of the first and latest combined images are following
```
  Date,      UT start, t-T0,   Exp.,  Filter, OT,    Err,  UL(3 sigma)
                     (mid, days)

2021-07-22  21:31:44 0.02572   5*60  CR      16.00  0.15   18.4
2021-07-22  23:13:54 0.09667   7*60  CR      17.33  0.12   19.0
```
The photometry is based on nearby USNO-B1.0 stars, R2 magnitude.
```
USNO-B1.0_id R2
USNO_B10-0836-00016699
USNO_B10-0836-00016715
```
We approximate the light curve by single PL model with power law index of -1.1 which is corroborating with PL index reported by Kumar et al. (GCN 30481). The light curve of our observations in Assy (Pankov et al., GCN 30478) and Kitab observatory can be found at http://grb.rssi.ru/GRB210722A/GRB210722A_LC.jpeg
GCN Circular #30489
S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB) H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 210722A (trigger #1061223) (D'Avanzo et al., GCN Circ. 30475). The BAT ground-calculated position is RA, Dec = 27.031, -6.347 deg which is
```
   RA(J2000)  =  01h 48m 07.4s
   Dec(J2000) = -06d 20' 49.9"
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 43%.
The mask-weighted light curve shows a single-peaked structure that starts at ~T-5 s, peaks at ~T0, and ends at ~T+30 s, with some weak tail emission that lasts until ~T+60 s. T90 (15-350 keV) is 50.20 +- 10.54 sec (estimated error including systematics).
The time-averaged spectrum from T-4.40 to T+59.59 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.62 +- 0.14. The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+1.00 sec in the 15-150 keV band is 2.2 +- 0.5 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/1061223/BA/
GCN Circular #30490
J. Wood (NASA/MSFC) reports on behalf of the Fermi GBM Team:
"At 20:54:40.87 UT on 22 July 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 210722A (trigger 648680085 / 210722871) which was also detected by the Swift/BAT and Swift/XRT (P. D'Avanzo et al. 2021, GCN 30475).
The GBM on-ground location is consistent with the Swift position.
The GBM light curve consists of a single peak with a duration (T90) of about 62 s (50-300 keV). The time-averaged spectrum from T0-1.5 s to T0+62 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.1 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 160 +/- 30 keV
The event fluence (10-1000 keV) in this time interval is (5.8 +/- 0.6)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.3 s in the 10-1000 keV band is 4.0 +/- 0.3 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/"
GCN Circular #30492
M. Jelinek, J. Strobl, R. Hudec, C. Polasek (ASU CAS Ondrejov) report:
We observed the position of the bright GRB 210722A (D'Avanzo et al., GCN 30475; Page et a., GCN 30483; Barthelmy et al. GCN 30489; and Wood, GCN 30490) with the D50 telescope of the Astronomical Institute Ondrejov, near Prague, Czech Republic. We performed a set of 35x 60s exposures in SDSS-i' filter on July 24 from 1:20 to 2:01 UT.
The optical afterglow (Zhu et al., GCN 30476; Pankov et al., GCN 30478 & 30488; Kumar et al., GCN 30481; Butler et al., GCN 30484; and Thoene et al., GCN 30487) is weakly detected in the overall combined image with the exposure mean time 28.9h after trigger. The Atlas-calibrated magnitude of the object is i' = 19.8 +/- 0.4.
GCN Circular #30494
N. Pankov (HSE, IKI), V. Kim (FAI, Pulkovo Observatory), A. Pozanenko (IKI), M. Krugov (FAI), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We continue observations of of the field of GRB 210722A (D'Avanzo et al., GCN 30475; Page et al., GCN 30483; Barthelmy et al. GCN 30489; Wood et al., GCN30490) with AZT-20 telescope of Assy-Turgen observatory. We obtained several frames in r' - filter starting on 21-07-23 (UT) 21:34:39. We clearly detect the bright optical afterglow (D'Avanzo et al., GCN 30475; Zhu et al., GCN 30476; Pankov et al., GCN 30478 & 30488; Kumar et al., GCN 30481; Butler et al., GCN 30484; Thoene et al., GCN 30487; Jelinek et al., GCN 30492).
Preliminary photometry of the afterglow in the stacked image is following
```
Date       UT start  t-T0       Exp.    Filter  OT    Err.  UL(3sigma)
                     (mid, days)  (s)             (AB)

2021-07-23 21:34:39 1.03677    26*60    r'      20.37 0.07  22.5
```
The photometry is based on the nearby PS1 stars.
The light curve can still be approximated by a single power law with a an index of -1.1.
GCN Circular #30504
S.Y. Fu (NAOC), Z.P. Zhu (NAOC, HUST), X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We continued to observe the field of GRB 210722A (D'Avanzo et al., GCN 30475) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 15x200 s frames in the Sloan r-band, starting at 20:41:20 UT on 2021-07-24, i.e., 1.99 days after the burst.
The previously reported optical afterglow (e.g., D'Avanzo et al., GCN 30475; Zhu et al., GCN 30476) is not detected in our stacked image, down to a limiting magnitude of r~21.0, calibrated with the nearby PanSTARRS field.
GCN Circular #30505
V. Kim (FAI, Pulkovo Observatory), A. Pozanenko (IKI), N. Pankov (HSE, IKI), M. Krugov (FAI), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We continue observations of of the field of GRB 210722A (D'Avanzo et al., GCN 30475; Page et al., GCN 30483; Barthelmy et al. GCN 30489; Wood et al., GCN30490) with AZT-20 telescope of Assy-Turgen observatory. We obtained several frames in r' - filter starting on 21-07-24 (UT) 21:34:39. We clearly detect the bright optical afterglow (D'Avanzo et al., GCN 30475; Zhu et al., GCN 30476; Pankov et al., GCN 30478, 30488, 30494; Kumar et al., GCN 30481; Butler et al., GCN 30484; Thoene et al., GCN 30487; Jelinek et al., GCN 30492; Fu et al., GCN 30504).
Preliminary photometry of the afterglow in the stacked image is following
```
Date       UT start  t-T0       Exp.    Filter  OT    Err.  UL(3sigma)
                     (mid, days)  (s)           (AB)

2021-07-24 20:56:07   n/d       42*60    r'     21.3  0.2   21.7
```
The photometry is based on the nearby PS1 stars.
The photometry is still compatible with the single power law of the afterglow light curve.
GCN Circular #31754
A. Klotz (CNRS-OMP-IRAP), M. Fortune, R. Augerai (Universite de la Renuion), P. Thierry� (AGORA), L. Eymar, S. Antier, M. Boer, A. de Ugarte Postigo (CNRS-OCA-ARTEMIS),
We analyzed archive images of the SWIFT trigger 1061223 (GRB 210722A, BAT detection by D'Avanzo et al. GCN Circ. 30475, early optical ground observations by Zhu et al. GCN Circ. 30476, redshift by Thoene et al. GCN Circ. 30487) with the TAROT robotic telescope (D=18cm) located at Les Makes Observatory, Reunion Island, France.
Images were acquired without any filter, camera FLI PL16803 and Takahashi Epsilon 180ED.
According the reference star NOMAD-1 0836-0016935 R=12.57 we give the photometry of the GRB optical transient:
```
t1(s) t2(s)���� R� dmag
 �2170� 2935 16.08� 0.16
 �2944� 4067 16.24� 0.12
 �4074� 4653 16.78� 0.14
 �4659� 5238 16.60� 0.14
 �5244� 6744 17.04� 0.22
```
t1 and t2 are start and stop acquisition since the trigger.
Magnitudes are not corrected for Galactic dust extinction.

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Jochen Greiner, last update: 13-Mar-2022 [Disclaimer]