Gamma-ray Burst 210725A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:48:02 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1061511,   Seg_Num: 0
GRB_RA:          215.363d {+14h 21m 27s} (J2000),
                 215.640d {+14h 22m 34s} (current),
                 214.719d {+14h 18m 53s} (1950)
GRB_DEC:          -1.177d {-01d 10' 36"} (J2000),
                  -1.275d {-01d 16' 28"} (current),
                  -0.949d {-00d 56' 55"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       11259 [cnts]    Image_Peak=343 [image_cnts]
TRIGGER_DUR:     5.504 [sec] 
TRIGGER_INDEX:   489     E_range: 50-350 keV
BKG_INTEN:       75412 [cnts]
BKG_TIME:        13556.57 SOD {03:45:56.57} UT
BKG_DUR:         48 [sec]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13622.93 SOD {03:47:02.93} UT
GRB_PHI:         -75.93 [deg]
GRB_THETA:        13.03 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     23.79 [sigma]
IMAGE_SIGNIF:    8.32 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +3  -1  +0  +0  +1  +0 
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 40"}
SUN_DIST:         91.30 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.25d {+21h 21m 00s}  -20.42d {-20d 25' 21"}
MOON_DIST:       103.21 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      343.98, 54.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      213.47, 12.20 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 191.81,19.81 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=648877628).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:47:28 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      44
TRIGGER_NUM:     648877628
GRB_RA:          217.700d {+14h 30m 48s} (J2000),
                 217.969d {+14h 31m 53s} (current),
                 217.076d {+14h 28m 18s} (1950)
GRB_DEC:          +5.533d {+05d 31' 60"} (J2000),
                  +5.438d {+05d 26' 19"} (current),
                  +5.755d {+05d 45' 16"} (1950)
GRB_ERROR:       20.07 [deg radius, statistical plus systematic]
GRB_INTEN:       110 [cnts/sec]
DATA_SIGNIF:     5.90 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13623.54 SOD {03:47:03.54} UT
GRB_PHI:         269.00 [deg]
GRB_THETA:        85.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.35
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      74%  GRB
2nd_MOST_LIKELY:  22%  Distant Particles
DETECTORS:       0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 40"}
SUN_DIST:         91.22 [deg]   Sun_angle= -6.2 [hr] (East of Sun)
MOON_POSTN:      320.25d {+21h 20m 59s}  -20.42d {-20d 25' 27"}
MOON_DIST:       103.38 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      354.99, 57.98 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      213.44, 19.30 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_lc_medres34_bn210725158.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 150.45,-25.42 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:47:37 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     648877628
GRB_RA:          217.733d {+14h 30m 56s} (J2000),
                 218.002d {+14h 32m 01s} (current),
                 217.110d {+14h 28m 26s} (1950)
GRB_DEC:          +5.633d {+05d 37' 60"} (J2000),
                  +5.539d {+05d 32' 19"} (current),
                  +5.854d {+05d 51' 16"} (1950)
GRB_ERROR:       11.02 [deg radius, statistical plus systematic]
GRB_INTEN:       120 [cnts/sec]
DATA_SIGNIF:     10.50 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13623.54 SOD {03:47:03.54} UT
GRB_PHI:         269.00 [deg]
GRB_THETA:        85.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.37
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      79%  GRB
2nd_MOST_LIKELY:  18%  Distant Particles
DETECTORS:       0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 40"}
SUN_DIST:         91.22 [deg]   Sun_angle= -6.2 [hr] (East of Sun)
MOON_POSTN:      320.25d {+21h 20m 59s}  -20.42d {-20d 25' 25"}
MOON_DIST:       103.39 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      355.16, 58.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      213.44, 19.41 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_lc_medres34_bn210725158.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 150.45,-25.42 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:47:47 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     648877628
GRB_RA:          216.070d {+14h 24m 17s} (J2000),
                 216.341d {+14h 25m 22s} (current),
                 215.442d {+14h 21m 46s} (1950)
GRB_DEC:          +4.150d {+04d 09' 00"} (J2000),
                  +4.053d {+04d 03' 11"} (current),
                  +4.376d {+04d 22' 33"} (1950)
GRB_ERROR:       4.21 [deg radius, statistical only]
DATA_SIGNIF:     10.60 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13623.54 SOD {03:47:03.54} UT
GRB_PHI:         270.00 [deg]
GRB_THETA:        83.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 40"}
SUN_DIST:         90.16 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.25d {+21h 21m 00s}  -20.42d {-20d 25' 24"}
MOON_DIST:       104.44 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      350.96, 58.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      212.32, 17.46 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_lc_medres34_bn210725158.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_648877628.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the CALET_GBM event (trignum=1311219774).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:48:54 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      1
TRIGGER_NUM:     648877628
GRB_RA:          216.090d {+14h 24m 22s} (J2000),
                 216.361d {+14h 25m 27s} (current),
                 215.462d {+14h 21m 51s} (1950)
GRB_DEC:          +4.210d {+04d 12' 36"} (J2000),
                  +4.113d {+04d 06' 47"} (current),
                  +4.436d {+04d 26' 09"} (1950)
GRB_ERROR:       2.64 [deg radius, statistical only]
DATA_SIGNIF:     12.70 [sigma]
DATA_INTERVAL:   9.216 [sec]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13623.54 SOD {03:47:03.54} UT
GRB_PHI:         270.00 [deg]
GRB_THETA:        83.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 40"}
SUN_DIST:         90.16 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.26d {+21h 21m 03s}  -20.42d {-20d 25' 13"}
MOON_DIST:       104.45 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      351.06, 58.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      212.32, 17.52 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_lc_medres34_bn210725158.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_648877628.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=1061511).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:48:28 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     648877628
GRB_RA:          216.080d {+14h 24m 19s} (J2000),
                 216.351d {+14h 25m 24s} (current),
                 215.452d {+14h 21m 48s} (1950)
GRB_DEC:          +4.180d {+04d 10' 48"} (J2000),
                  +4.083d {+04d 04' 59"} (current),
                  +4.406d {+04d 24' 21"} (1950)
GRB_ERROR:       3.92 [deg radius, statistical only]
DATA_SIGNIF:     12.40 [sigma]
DATA_INTERVAL:   8.192 [sec]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13623.54 SOD {03:47:03.54} UT
GRB_PHI:         270.00 [deg]
GRB_THETA:        83.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 40"}
SUN_DIST:         90.16 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.26d {+21h 21m 01s}  -20.42d {-20d 25' 17"}
MOON_DIST:       104.45 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      351.01, 58.10 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      212.32, 17.49 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_lc_medres34_bn210725158.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_648877628.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=1061511).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:57:20 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     648877628
GRB_RA:          216.090d {+14h 24m 22s} (J2000),
                 216.361d {+14h 25m 27s} (current),
                 215.462d {+14h 21m 51s} (1950)
GRB_DEC:          +4.210d {+04d 12' 36"} (J2000),
                  +4.113d {+04d 06' 47"} (current),
                  +4.436d {+04d 26' 09"} (1950)
GRB_ERROR:       3.08 [deg radius, statistical only]
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13623.54 SOD {03:47:03.54} UT
GRB_PHI:         270.00 [deg]
GRB_THETA:        83.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       124.73d {+08h 18m 54s}  +19.61d {+19d 36' 35"}
SUN_DIST:         90.16 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.34d {+21h 21m 23s}  -20.40d {-20d 23' 52"}
MOON_DIST:       104.53 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      351.06, 58.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      212.32, 17.52 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_lc_medres34_bn210725158.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210725158/quicklook/glg_locplot_all_bn210725158.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=1061511).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:48:59 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.383d {+14h 21m 32s} (J2000)
POINT_DEC:        -1.189d {-01d 11' 20"} (J2000)
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13733.64 SOD {03:48:53.64} UT,   110.7 [sec] since BAT Trigger Time
COUNTS:          7    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:50:45 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1061511,   Seg_Num: 0
GRB_RA:          215.363d {+14h 21m 27s} (J2000),
                 215.640d {+14h 22m 34s} (current),
                 214.719d {+14h 18m 53s} (1950)
GRB_DEC:          -1.177d {-01d 10' 36"} (J2000),
                  -1.275d {-01d 16' 28"} (current),
                  -0.949d {-00d 56' 55"} (1950)
GRB_DATE:        19420 TJD;   206 DOY;   21/07/25
GRB_TIME:        13622.93 SOD {03:47:02.93} UT
TRIGGER_INDEX:   489
GRB_PHI:         -75.93 [deg]
GRB_THETA:        13.03 [deg]
DELTA_TIME:      -76.00 [sec]
TRIGGER_DUR:     5.504 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     23.79 [sigma]
IMAGE_SIGNIF:    8.32 [sigma]
LC_URL:          sw01061511000msb.lc
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 39"}
SUN_DIST:         91.29 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.28d {+21h 21m 07s}  -20.42d {-20d 24' 55"}
MOON_DIST:       103.24 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      343.98, 54.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      213.47, 12.20 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 191.81,19.81 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:52:05 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.383d {+14h 21m 32s} (J2000)
POINT_DEC:        -1.189d {-01d 11' 20"} (J2000)
POINT_ROLL:      289.580d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13737.45 SOD {03:48:57.45} UT,   114.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.820
N_STARS:         28
X_OFFSET:        658 [pixels]
Y_OFFSET:        494 [pixels]
X_MAX:           1617 [pixels]
Y_MAX:           1453 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01061511000msufc0114.fits
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 38"}
SUN_DIST:         91.32 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.29d {+21h 21m 10s}  -20.41d {-20d 24' 42"}
MOON_DIST:       103.23 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.49, 12.19 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:52:30 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.383d {+14h 21m 32s} (J2000)
POINT_DEC:        -1.189d {-01d 11' 20"} (J2000)
POINT_ROLL:      289.580d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13737.45 SOD {03:48:57.45} UT,   114.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.820
N_STARS:         28
X_OFFSET:        658 [pixels]
Y_OFFSET:        494 [pixels]
X_MAX:           1617 [pixels]
Y_MAX:           1453 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01061511000msufc0114.fits
SUN_POSTN:       124.72d {+08h 18m 53s}  +19.61d {+19d 36' 38"}
SUN_DIST:         91.32 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.30d {+21h 21m 11s}  -20.41d {-20d 24' 38"}
MOON_DIST:       103.23 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.49, 12.19 [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:     Sun 25 Jul 21 03:59:59 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 23"} (J2000)
POINT_ROLL:      289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13895.99 SOD {03:51:35.99} UT,   273.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.739
N_STARS:         35
X_OFFSET:        418 [pixels]
Y_OFFSET:        254 [pixels]
X_MAX:           1857 [pixels]
Y_MAX:           1693 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw01061511000msufc0273.fits
SUN_POSTN:       124.73d {+08h 18m 55s}  +19.61d {+19d 36' 34"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.37d {+21h 21m 29s}  -20.39d {-20d 23' 26"}
MOON_DIST:       103.30 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 04:01:22 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 23"} (J2000)
ROLL:            289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13895.99 SOD {03:51:35.99} UT,   273.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     648877923
X_OFFSET:        977 [pixels]
Y_OFFSET:        813 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1137
Y_GRB_POS:       973
BINNING_INDEX:   1
IM_URL:          sw01061511000msuni0301.fits
SUN_POSTN:       124.73d {+08h 18m 55s}  +19.61d {+19d 36' 33"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.38d {+21h 21m 32s}  -20.39d {-20d 23' 13"}
MOON_DIST:       103.32 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [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 Circular #30500
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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB210725.16 (trigger No 1061511,14h 21m 27.12s , -01d 10m 37.2s, R=0.05) errorbox 78 sec after notice time and 169 sec after trigger time at 2021-07-25 03:49:52 UT, with upper limit up to 16.5 mag. The observations began at zenith distance = 79 deg. The sun altitude is -73.8 deg.
The galactic latitude b = 54 deg., longitude l = 345 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1669654
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     185 |         MASTER-OAFA |   C |    30 | 16.3 |        
     239 |         MASTER-OAFA |   C |    40 | 16.4 |        
     304 |         MASTER-OAFA |   C |    50 | 16.5 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 04:00:21 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1061511,   Seg_Num: 0
GRB_RA:          215.3737d {+14h 21m 29.68s} (J2000),
                 215.6515d {+14h 22m 36.35s} (current),
                 214.7302d {+14h 18m 55.24s} (1950)
GRB_DEC:          -1.1931d {-01d 11' 35.1"} (J2000),
                  -1.2908d {-01d 17' 26.9"} (current),
                  -0.9652d {-00d 57' 54.6"} (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:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13813.00 SOD {03:50:13.00} UT,   190.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       124.73d {+08h 18m 55s}  +19.61d {+19d 36' 33"}
SUN_DIST:         91.30 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.37d {+21h 21m 30s}  -20.39d {-20d 23' 23"}
MOON_DIST:       103.32 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      343.98, 54.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      213.49, 12.19 [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:     Sun 25 Jul 21 04:00:12 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 23"} (J2000)
POINT_ROLL:      289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13895.99 SOD {03:51:35.99} UT,   273.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.739
N_STARS:         35
X_OFFSET:        418 [pixels]
Y_OFFSET:        254 [pixels]
X_MAX:           1857 [pixels]
Y_MAX:           1693 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw01061511000msufc0273.fits
SUN_POSTN:       124.73d {+08h 18m 55s}  +19.61d {+19d 36' 33"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.37d {+21h 21m 30s}  -20.39d {-20d 23' 24"}
MOON_DIST:       103.30 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [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:     Sun 25 Jul 21 04:01:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 23"} (J2000)
ROLL:            289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13895.99 SOD {03:51:35.99} UT,   273.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     648877923
X_OFFSET:        977 [pixels]
Y_OFFSET:        813 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1137
Y_GRB_POS:       973
BINNING_INDEX:   1
IM_URL:          sw01061511000msuni0301.fits
SUN_POSTN:       124.73d {+08h 18m 55s}  +19.61d {+19d 36' 33"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.39d {+21h 21m 33s}  -20.39d {-20d 23' 11"}
MOON_DIST:       103.32 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 04:08:22 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 24"} (J2000)
POINT_ROLL:      289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  14498.90 SOD {04:01:38.90} UT,   876.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.785
N_STARS:         60
X_OFFSET:        418 [pixels]
Y_OFFSET:        254 [pixels]
X_MAX:           1857 [pixels]
Y_MAX:           1693 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01061511000msufc0875.fits
SUN_POSTN:       124.73d {+08h 18m 56s}  +19.61d {+19d 36' 29"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.45d {+21h 21m 49s}  -20.37d {-20d 22' 05"}
MOON_DIST:       103.38 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:53:38 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.383d {+14h 21m 32s} (J2000)
POINT_DEC:        -1.189d {-01d 11' 20"} (J2000)
ROLL:            289.580d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13737.45 SOD {03:48:57.45} UT,   114.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648877764
X_OFFSET:        977 [pixels]
Y_OFFSET:        813 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1137
Y_GRB_POS:       973
BINNING_INDEX:   1
IM_URL:          sw01061511000msuni0142.fits
SUN_POSTN:       124.72d {+08h 18m 54s}  +19.61d {+19d 36' 37"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.31d {+21h 21m 14s}  -20.41d {-20d 24' 28"}
MOON_DIST:       103.24 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.49, 12.19 [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:     Sun 25 Jul 21 04:08:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 24"} (J2000)
POINT_ROLL:      289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  14498.90 SOD {04:01:38.90} UT,   876.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.785
N_STARS:         60
X_OFFSET:        418 [pixels]
Y_OFFSET:        254 [pixels]
X_MAX:           1857 [pixels]
Y_MAX:           1693 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01061511000msufc0875.fits
SUN_POSTN:       124.73d {+08h 18m 56s}  +19.61d {+19d 36' 29"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.46d {+21h 21m 50s}  -20.37d {-20d 22' 03"}
MOON_DIST:       103.38 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN Circular #30501
M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB), N. J. Klingler (GSFC/UMBC/CRESSTII), A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), D. M. Palmer (LANL) and T. Sbarrato (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team:
At 03:47:02 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210725A (trigger=1061511). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 215.363, -1.177 which is
```
   RA(J2000) = 14h 21m 27s
   Dec(J2000) = -01d 10' 36"
```
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 10 sec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 03:48:53.6 UT, 110.7 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 215.3742, -1.1934 which is equivalent to:
```
   RA(J2000)  = 14h 21m 29.81s
   Dec(J2000) = -01d 11' 36.2"
```
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This position may be improved as more data are received; the latest position is available at https://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 (4.09 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.9 (+2.81/-2.40) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 114 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 none of the XRT error circle. 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 0.046.
Burst Advocate for this burst is M. G. Bernardini (grazia.bernardini 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/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 04:09:45 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 24"} (J2000)
ROLL:            289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  14498.90 SOD {04:01:38.90} UT,   876.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648878526
X_OFFSET:        977 [pixels]
Y_OFFSET:        813 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1137
Y_GRB_POS:       973
BINNING_INDEX:   1
IM_URL:          sw01061511000msuni0903.fits
SUN_POSTN:       124.73d {+08h 18m 56s}  +19.61d {+19d 36' 28"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.47d {+21h 21m 52s}  -20.36d {-20d 21' 52"}
MOON_DIST:       103.40 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [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:     Sun 25 Jul 21 03:53:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.383d {+14h 21m 32s} (J2000)
POINT_DEC:        -1.189d {-01d 11' 20"} (J2000)
ROLL:            289.580d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13737.45 SOD {03:48:57.45} UT,   114.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648877764
X_OFFSET:        977 [pixels]
Y_OFFSET:        813 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1137
Y_GRB_POS:       973
BINNING_INDEX:   1
IM_URL:          sw01061511000msuni0142.fits
SUN_POSTN:       124.72d {+08h 18m 54s}  +19.61d {+19d 36' 37"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.31d {+21h 21m 14s}  -20.41d {-20d 24' 25"}
MOON_DIST:       103.25 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      344.00, 54.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.49, 12.19 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 03:53:40 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1061511,   Seg_Num: 0
GRB_RA:          215.3754d {+14h 21m 30.09s} (J2000),
                 215.6532d {+14h 22m 36.76s} (current),
                 214.7319d {+14h 18m 55.64s} (1950)
GRB_DEC:          -1.1943d {-01d 11' 39.4"} (J2000),
                  -1.2920d {-01d 17' 31.2"} (current),
                  -0.9664d {-00d 57' 59.0"} (1950)
GRB_ERROR:       7.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  13813.00 SOD {03:50:13.00} UT,   190.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       124.72d {+08h 18m 54s}  +19.61d {+19d 36' 37"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.31d {+21h 21m 14s}  -20.41d {-20d 24' 27"}
MOON_DIST:       103.25 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      343.98, 54.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      213.49, 12.19 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
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 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 25 Jul 21 04:09:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1061511,   Seg_Num: 0
POINT_RA:        215.386d {+14h 21m 33s} (J2000)
POINT_DEC:        -1.190d {-01d 11' 24"} (J2000)
ROLL:            289.579d
IMG_START_DATE:  19420 TJD;   206 DOY;   21/07/25
IMG_START_TIME:  14498.90 SOD {04:01:38.90} UT,   876.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     648878526
X_OFFSET:        977 [pixels]
Y_OFFSET:        813 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1137
Y_GRB_POS:       973
BINNING_INDEX:   1
IM_URL:          sw01061511000msuni0903.fits
SUN_POSTN:       124.73d {+08h 18m 56s}  +19.61d {+19d 36' 28"}
SUN_DIST:         91.31 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:      320.47d {+21h 21m 53s}  -20.36d {-20d 21' 50"}
MOON_DIST:       103.40 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:      344.00, 54.33 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      213.50, 12.19 [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 #30503
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 210725A (Bernardini et al., GCN 30501) starting at 56 minutes after the burst. A total of 30x60s images were obtained in the clear (roughly R) filters. We do not detect any optical afterglow candidate within the XRT position error circle (Bernardini et al., GCN 30501), neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 18.5 mag calibrated to the PS1 catalog.
GCN Circular #30507
S. Torii (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
The long GRB 210725A (Swift detection: Bernardini et al., GCN Circ. 30501; https://gcn.gsfc.nasa.gov/other/210725A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 03:47:01.565 UTC on 25 July 2021 (http://cgbm.calet.jp/cgbm_trigger/flight/1311219774/index.html). The burst signal was seen only by the SGM detector.
The burst light curve shows a single weak pulse which starts at T+1.4 sec, peaks at T+1.5 sec,and ends at T+6.9 sec. The T90 and T50 durations measured by the SGM data are 5.0 +- 0.7 sec and 3.0 +- 0.9 sec (40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1311219774/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
GCN Circular #30509
M. Niwano, R. Hosokawa, K. L. Murata, N. Ito, H. Takamatsu, Y. Imai, R. Noto, S. Sato, M. Takaku, R. Yamaguchi, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 210725A (Bernardini et al. GCN Circular #30501, WeiKang Zheng et al. GCN Circular #30503, S. Torii et al. GCN Circular #30507) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 60 sec exposures started at 2021-07-25 10:26:07 UT (6.7 hours after Swift BAT trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the XRT error region (Bernardini et al. GCN Circular #30501). We obtained the 5-sigma limits of the stacked images as follows.
```
T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
6.7 2021-07-25 11:21:56.58 900 g'>18.6, Rc>18.9, Ic>18.4
------------------------------------------------------------------------------------------------
T-EXP: Total Exposure time
```
We used PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN Circular #30514
A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), M. G. Bernardini (INAF-OAB), H. A. Krimm (NSF), S. Laha (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 210725A (trigger #1061511) (Bernardini et al., GCN Circ. 30501). The BAT ground-calculated position is RA, Dec = 215.381, -1.177 deg which is
```
   RA(J2000)  =  14h 21m 31.4s
   Dec(J2000) = -01d 10' 37.2"
```
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 92%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~T0 and ends at ~T+60 s. The main peak occurs at ~T+1 s. T90 (15-350 keV) is 53.54 +- 11.25 sec (estimated error including systematics).
The time-averaged spectrum from T-0.82 to T+59.86 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.42 +- 0.32. The fluence in the 15-150 keV band is 8.1 +- 1.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+1.01 sec in the 15-150 keV band is 1.0 +- 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/1061511/BA/
GCN Circular #30517
M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and M.G. Bernardini report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 210725A (Bernardini et al. GCN Circ. 30501), from 114 s to 64.8 ks after the BAT trigger. The data comprise 74 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. Using 1409 s of PC mode data and 2 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 = 215.37414, -1.19268 which is equivalent to:
```
RA (J2000): 14h 21m 29.79s
Dec(J2000): -01d 11' 33.6"
```
with an uncertainty of 1.9 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.99 (+/-0.08).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.48 (+0.21, -0.19). The best-fitting absorption column is 8.0 (+6.8, -3.9) x 10^20 cm^-2, consistent with the Galactic value of 4.1 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.5 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     8.0 (+6.8, -3.9) x 10^20 cm^-2
Galactic foreground: 4.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.48 (+0.21, -0.19)
```
If the light curve continues to decay with a power-law decay index of 1.99, the count rate at T+24 hours will be 1.2 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.6 x 10^-16 (6.1 x 10^-16) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01061511.
This circular is an official product of the Swift-XRT team.
GCN Circular #30519
S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 03:47:03.54 UT on 25 July 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 210725A (trigger 648877628 / 210725158) which was also detected by the Swift/BAT (Bernardini et al. 2021, GCN 30501). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 78 degrees.
The GBM light curve consists of a single peak followed by some extended emission with a duration (T90) of about 47 s (50-300 keV). The time-averaged spectrum from T0-1.02 s to T0+9.21 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.37 +/- 0.22 and the cutoff energy, parameterized as Epeak, is 460 +/- 104 keV.
The event fluence (10-1000 keV) in this time interval is (3.14 +/- 0.35)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.64 s in the 10-1000 keV band is 2.0 +/- 0.2 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 #30527
M. H. Siegel (PSU) and M. G. Bernardini (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210725A 114 s after the BAT trigger (Bernardini et al., GCN Circ. 30501). No optical afterglow consistent with the XRT position (Perri et al. GCN Circ. 30517) 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)         114          264          147         >20.7
u (fc)             273          523          246         >20.2
white              114         1545          392         >21.0
v                  603         1595          117         >19.1
b                  529         1519           97         >20.4
u                  273         1495          343         >20.4
w1                 653         1470           97         >19.2
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.047 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #30530
N. Pankov (HSE, IKI), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI), S. Belkin (IKI), V. R. Ayvazian (AbAO), G. V. Kapanadze (AbAO), report on behalf of GRB IKI FuN:
We observed the field of GRB 210725A (Bernardini et al. GCN 30501; Torii et al. GCN 30507; Poolakkil et al. GCN 30519) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on July, 25 (UT) 19:11:58. We do not detect any object in the enhanced XRT position (Perri et al. GCN 30517). The non detection is consistent with optical observations (Zheng et al. GCN 30503; Niwano et al., GCN 30509; Siegel et al. GCN 30527).
Preliminary photometry of the field is following
```
Date       UT start   t-T0    Filter Exp.    OT   Err.  UL(3sigma)
                        (mid, days)    (s)

2021-07-25 19:11:58   0.65481  R     36*60   n/d  n/d   20.8
```
The photometry is based on the nearby stars:
```
USNO-B1.0 R2
USNO_B10_id R2
0888-00234198 14.31
0888-00234167 15.25
```

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Jochen Greiner, last update: 27-Jul-2021 [Disclaimer]