Gamma-ray Burst 210807C

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:58:49 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1064421,   Seg_Num: 0
GRB_RA:          143.551d {+09h 34m 12s} (J2000),
                 143.738d {+09h 34m 57s} (current),
                 143.118d {+09h 32m 28s} (1950)
GRB_DEC:         -51.409d {-51d 24' 31"} (J2000),
                 -51.506d {-51d 30' 20"} (current),
                 -51.186d {-51d 11' 07"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=3807 [image_cnts]
TRIGGER_DUR:     88.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82628.49 SOD {22:57:08.49} UT
GRB_PHI:         -150.61 [deg]
GRB_THETA:        50.81 [deg]
SOLN_STATUS:     0x2013
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    19.28 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +6  +0  +1 -37  +0 
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 35"}
SUN_DIST:         67.83 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      131.94d {+08h 47m 46s}  +22.33d {+22d 19' 49"}
MOON_DIST:        74.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.71,  0.32 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      176.68,-59.83 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are
 undefined.)  
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:        There is a bright star (mag=5.01) 9.23 arcmin from this position.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 214.98,4.44 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:55:48 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     650069729
GRB_RA:          146.733d {+09h 46m 56s} (J2000),
                 146.937d {+09h 47m 45s} (current),
                 146.263d {+09h 45m 03s} (1950)
GRB_DEC:         -48.100d {-48d 06' 00"} (J2000),
                 -48.201d {-48d 12' 01"} (current),
                 -47.868d {-47d 52' 03"} (1950)
GRB_ERROR:       14.77 [deg radius, statistical plus systematic]
GRB_INTEN:       79 [cnts/sec]
DATA_SIGNIF:     6.60 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         302.00 [deg]
GRB_THETA:        60.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.95
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      77%  GRB
2nd_MOST_LIKELY:  21%  Distant Particles
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 37"}
SUN_DIST:         64.83 [deg]   Sun_angle= -0.6 [hr] (East of Sun)
MOON_POSTN:      131.91d {+08h 47m 39s}  +22.34d {+22d 20' 10"}
MOON_DIST:        71.81 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.07,  4.16 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      175.90,-55.96 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 116.33,-25.58 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:55:57 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      59
TRIGGER_NUM:     650069729
GRB_RA:          142.950d {+09h 31m 48s} (J2000),
                 143.114d {+09h 32m 27s} (current),
                 142.571d {+09h 30m 17s} (1950)
GRB_DEC:         -57.367d {-57d 22' 00"} (J2000),
                 -57.463d {-57d 27' 45"} (current),
                 -57.145d {-57d 08' 41"} (1950)
GRB_ERROR:       6.05 [deg radius, statistical plus systematic]
GRB_INTEN:       306 [cnts/sec]
DATA_SIGNIF:     17.90 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         292.00 [deg]
GRB_THETA:        55.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.97
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   3%  Distant Particles
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 37"}
SUN_DIST:         73.72 [deg]   Sun_angle= -0.3 [hr] (East of Sun)
MOON_POSTN:      131.92d {+08h 47m 40s}  +22.34d {+22d 20' 09"}
MOON_DIST:        80.35 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      278.49, -4.30 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      184.90,-64.41 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 116.33,-25.58 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:56:07 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      70
TRIGGER_NUM:     650069729
GRB_RA:          132.133d {+08h 48m 32s} (J2000),
                 132.277d {+08h 49m 06s} (current),
                 131.801d {+08h 47m 12s} (1950)
GRB_DEC:         -56.200d {-56d 12' 00"} (J2000),
                 -56.281d {-56d 16' 50"} (current),
                 -56.014d {-56d 00' 49"} (1950)
GRB_ERROR:       6.13 [deg radius, statistical plus systematic]
GRB_INTEN:       382 [cnts/sec]
DATA_SIGNIF:     30.20 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         295.00 [deg]
GRB_THETA:        50.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.85
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic Transient
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         72.59 [deg]   Sun_angle= 0.4 [hr] (West of Sun)
MOON_POSTN:      131.92d {+08h 47m 40s}  +22.34d {+22d 20' 08"}
MOON_DIST:        78.62 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      273.60, -7.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      172.68,-67.90 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 116.33,-25.58 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:56:05 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     650069729
GRB_RA:          145.970d {+09h 43m 53s} (J2000),
                 146.177d {+09h 44m 43s} (current),
                 145.491d {+09h 41m 58s} (1950)
GRB_DEC:         -45.900d {-45d 53' 59"} (J2000),
                 -46.000d {-45d 59' 58"} (current),
                 -45.670d {-45d 40' 11"} (1950)
GRB_ERROR:       7.02 [deg radius, statistical only]
DATA_SIGNIF:     12.60 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         304.00 [deg]
GRB_THETA:        61.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         62.57 [deg]   Sun_angle= -0.5 [hr] (East of Sun)
MOON_POSTN:      131.92d {+08h 47m 40s}  +22.34d {+22d 20' 08"}
MOON_DIST:        69.55 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      272.24,  5.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      172.92,-54.47 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_650069729.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:56:45 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     650069729
GRB_RA:          149.590d {+09h 58m 22s} (J2000),
                 149.809d {+09h 59m 14s} (current),
                 149.085d {+09h 56m 20s} (1950)
GRB_DEC:         -43.750d {-43d 45' 00"} (J2000),
                 -43.854d {-43d 51' 13"} (current),
                 -43.511d {-43d 30' 37"} (1950)
GRB_ERROR:       5.57 [deg radius, statistical only]
DATA_SIGNIF:     14.20 [sigma]
DATA_INTERVAL:   8.192 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         305.00 [deg]
GRB_THETA:        64.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         60.94 [deg]   Sun_angle= -0.8 [hr] (East of Sun)
MOON_POSTN:      131.92d {+08h 47m 42s}  +22.33d {+22d 20' 04"}
MOON_DIST:        68.19 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      272.86,  8.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      174.46,-51.25 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_650069729.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(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9335).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:56:54 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      1
TRIGGER_NUM:     650069729
GRB_RA:          147.090d {+09h 48m 22s} (J2000),
                 147.297d {+09h 49m 11s} (current),
                 146.611d {+09h 46m 27s} (1950)
GRB_DEC:         -46.790d {-46d 47' 23"} (J2000),
                 -46.891d {-46d 53' 27"} (current),
                 -46.557d {-46d 33' 24"} (1950)
GRB_ERROR:       5.33 [deg radius, statistical only]
DATA_SIGNIF:     19.00 [sigma]
DATA_INTERVAL:   10.240 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         303.00 [deg]
GRB_THETA:        61.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         63.57 [deg]   Sun_angle= -0.6 [hr] (East of Sun)
MOON_POSTN:      131.92d {+08h 47m 42s}  +22.33d {+22d 20' 02"}
MOON_DIST:        70.60 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      273.41,  5.32 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      174.89,-54.75 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_650069729.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(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9335).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:57:03 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      2
TRIGGER_NUM:     650069729
GRB_RA:          150.750d {+10h 03m 00s} (J2000),
                 150.959d {+10h 03m 50s} (current),
                 150.268d {+10h 01m 04s} (1950)
GRB_DEC:         -49.260d {-49d 15' 35"} (J2000),
                 -49.365d {-49d 21' 53"} (current),
                 -49.018d {-49d 01' 03"} (1950)
GRB_ERROR:       2.72 [deg radius, statistical only]
DATA_SIGNIF:     27.90 [sigma]
DATA_INTERVAL:   13.312 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         299.00 [deg]
GRB_THETA:        62.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         66.49 [deg]   Sun_angle= -0.9 [hr] (East of Sun)
MOON_POSTN:      131.93d {+08h 47m 42s}  +22.33d {+22d 20' 01"}
MOON_DIST:        73.68 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      276.88,  4.90 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      180.89,-55.29 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_650069729.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(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9335).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:57:13 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      3
TRIGGER_NUM:     650069729
GRB_RA:          148.350d {+09h 53m 24s} (J2000),
                 148.554d {+09h 54m 13s} (current),
                 147.877d {+09h 51m 31s} (1950)
GRB_DEC:         -48.920d {-48d 55' 11"} (J2000),
                 -49.022d {-49d 01' 20"} (current),
                 -48.684d {-48d 41' 00"} (1950)
GRB_ERROR:       1.97 [deg radius, statistical only]
DATA_SIGNIF:     39.00 [sigma]
DATA_INTERVAL:   17.408 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         300.00 [deg]
GRB_THETA:        61.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         65.82 [deg]   Sun_angle= -0.7 [hr] (East of Sun)
MOON_POSTN:      131.93d {+08h 47m 43s}  +22.33d {+22d 20' 00"}
MOON_DIST:        72.88 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      275.42,  4.21 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      178.31,-55.97 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_650069729.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(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9335).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 22:57:21 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      4
TRIGGER_NUM:     650069729
GRB_RA:          145.780d {+09h 43m 07s} (J2000),
                 145.975d {+09h 43m 54s} (current),
                 145.330d {+09h 41m 19s} (1950)
GRB_DEC:         -50.520d {-50d 31' 11"} (J2000),
                 -50.620d {-50d 37' 09"} (current),
                 -50.290d {-50d 17' 24"} (1950)
GRB_ERROR:       1.75 [deg radius, statistical only]
DATA_SIGNIF:     44.40 [sigma]
DATA_INTERVAL:   21.504 [sec]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         299.00 [deg]
GRB_THETA:        59.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 26s}  +16.14d {+16d 08' 36"}
SUN_DIST:         67.12 [deg]   Sun_angle= -0.5 [hr] (East of Sun)
MOON_POSTN:      131.93d {+08h 47m 43s}  +22.33d {+22d 19' 59"}
MOON_DIST:        74.00 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      275.17,  1.91 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      177.71,-58.25 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_650069729.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
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(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9335).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:04:46 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     650069729
GRB_RA:          147.550d {+09h 50m 12s} (J2000),
                 147.746d {+09h 50m 59s} (current),
                 147.097d {+09h 48m 23s} (1950)
GRB_DEC:         -51.440d {-51d 26' 23"} (J2000),
                 -51.542d {-51d 32' 29"} (current),
                 -51.206d {-51d 12' 19"} (1950)
GRB_ERROR:       1.66 [deg radius, statistical only]
GRB_DATE:        19433 TJD;   219 DOY;   21/08/07
GRB_TIME:        82524.31 SOD {22:55:24.31} UT
GRB_PHI:         297.00 [deg]
GRB_THETA:        60.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 30"}
SUN_DIST:         68.20 [deg]   Sun_angle= -0.6 [hr] (East of Sun)
MOON_POSTN:      132.00d {+08h 48m 00s}  +22.32d {+22d 19' 06"}
MOON_DIST:        75.14 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      276.61,  1.93 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      180.46,-58.26 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_locplot_all_bn210807955.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:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9335).

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sat 07 Aug 21 22:56:40 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    9335,   Sub_Num: 0
GRB_INTEN:      9.08 [sigma]
GRB_TIME:       82524.59 SOD {22:55:24.59} UT
GRB_DATE:       19433 TJD;   219 DOY;   21/08/07
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.  
COMMENTS:       Time_Scale=2.0000 and Time_Error=1.0000.  
COMMENTS:
COMMENTS:       NOTE: This SPIACS event is temporally(0.0<100sec) coincident with the FER
MI_GBM event (trignum=650069729).  
COMMENTS:          
COMMENTS:       The SPIACS lightcurve can be found at:  
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2021-08/2021-08-07T22-55-24.39
19-11513-48016-0.lc

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:21:32 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1064421,   Seg_Num: 0
GRB_RA:          143.5345d {+09h 34m 08.28s} (J2000),
                 143.7218d {+09h 34m 53.22s} (current),
                 143.1015d {+09h 32m 24.36s} (1950)
GRB_DEC:         -51.4023d {-51d 24' 08.2"} (J2000),
                 -51.4991d {-51d 29' 56.8"} (current),
                 -51.1790d {-51d 10' 44.5"} (1950)
GRB_ERROR:       7.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  83017.00 SOD {23:03:37.00} UT,   388.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       138.12d {+09h 12m 30s}  +16.14d {+16d 08' 18"}
SUN_DIST:         67.81 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      132.16d {+08h 48m 38s}  +22.28d {+22d 17' 06"}
MOON_DIST:        74.48 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.69,  0.32 [deg] galactic lon,lat of the burst
ECL_COORDS:      176.66,-59.83 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        There is a bright star (mag=5.01) 8.82 arcmin from the XRT position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:40:14 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1064421,   Seg_Num: 0
GRB_RA:          143.5344d {+09h 34m 08.25s} (J2000),
                 143.7217d {+09h 34m 53.20s} (current),
                 143.1014d {+09h 32m 24.33s} (1950)
GRB_DEC:         -51.4024d {-51d 24' 08.6"} (J2000),
                 -51.4992d {-51d 29' 57.2"} (current),
                 -51.1791d {-51d 10' 44.8"} (1950)
GRB_ERROR:       7.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  83017.00 SOD {23:03:37.00} UT,   388.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       138.14d {+09h 12m 33s}  +16.13d {+16d 08' 05"}
SUN_DIST:         67.81 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      132.33d {+08h 49m 20s}  +22.25d {+22d 14' 51"}
MOON_DIST:        74.42 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.69,  0.32 [deg] galactic lon,lat of the burst
ECL_COORDS:      176.66,-59.83 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        There is a bright star (mag=5.01) 8.83 arcmin from the XRT position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:00:43 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1064421,   Seg_Num: 0
GRB_RA:          143.5366d {+09h 34m 08.7s} (J2000),
                 143.7239d {+09h 34m 53.7s} (current),
                 143.1036d {+09h 32m 24.8s} (1950)
GRB_DEC:         -51.4028d {-51d 24' 10.0"} (J2000),
                 -51.4996d {-51d 29' 58.6"} (current),
                 -51.1795d {-51d 10' 46.2"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       64 [cnts]
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82805.59 SOD {23:00:05.59} UT,   177.1 [sec] since BAT Trigger Time
CENTROID_X:      264.23,  raw= 264  [pixels]
CENTROID_Y:      331.46,  raw= 331  [pixels]
ROLL:            354.34 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   78.64
GRB_POS_XRT_Z:   -101.76
IMAGE_URL:       sw01064421000msxps_rw.img
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 33"}
SUN_DIST:         67.82 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      131.96d {+08h 47m 51s}  +22.33d {+22d 19' 35"}
MOON_DIST:        74.55 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.69,  0.32 [deg] galactic lon,lat of the burst
ECL_COORDS:      176.66,-59.83 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        There is a bright star (mag=5.01) 9.23 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:00:46 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1064421,   Seg_Num: 0
GRB_RA:          143.5366d {+09h 34m 08.7s} (J2000),
                 143.7239d {+09h 34m 53.7s} (current),
                 143.1036d {+09h 32m 24.8s} (1950)
GRB_DEC:         -51.4028d {-51d 24' 10.0"} (J2000),
                 -51.4996d {-51d 29' 58.6"} (current),
                 -51.1795d {-51d 10' 46.2"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       64 [cnts]
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82805.59 SOD {23:00:05.59} UT,   177.1 [sec] since BAT Trigger Time
CENTROID_X:      264.23,  raw= 264  [pixels]
CENTROID_Y:      331.46,  raw= 331  [pixels]
ROLL:            354.34 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   78.64
GRB_POS_XRT_Z:   -101.76
IMAGE_URL:       sw01064421000msxps_rw.img
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 33"}
SUN_DIST:         67.82 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      131.96d {+08h 47m 51s}  +22.33d {+22d 19' 35"}
MOON_DIST:        74.55 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.69,  0.32 [deg] galactic lon,lat of the burst
ECL_COORDS:      176.66,-59.83 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        There is a bright star (mag=5.01) 9.23 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:06:04 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1064421,   Seg_Num: 0
POINT_RA:        143.576d {+09h 34m 18s} (J2000)
POINT_DEC:       -51.429d {-51d 25' 42"} (J2000)
ROLL:            354.336d
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82808.74 SOD {23:00:08.74} UT,   180.2 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     650070036
X_OFFSET:        895 [pixels]
Y_OFFSET:        625 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1055
Y_GRB_POS:       785
BINNING_INDEX:   1
IM_URL:          sw01064421000msuni0208.fits
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 29"}
SUN_DIST:         67.85 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      132.01d {+08h 48m 03s}  +22.32d {+22d 18' 57"}
MOON_DIST:        74.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.73,  0.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      176.73,-59.83 [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).  
COMMENTS:        There is a bright star (mag=5.01) 9.23 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:04:41 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1064421,   Seg_Num: 0
POINT_RA:        143.576d {+09h 34m 18s} (J2000)
POINT_DEC:       -51.429d {-51d 25' 42"} (J2000)
POINT_ROLL:      354.336d
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82808.74 SOD {23:00:08.74} UT,   180.2 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.678
N_STARS:         84
X_OFFSET:        560 [pixels]
Y_OFFSET:        376 [pixels]
X_MAX:           1519 [pixels]
Y_MAX:           1335 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw01064421000msufc0180.fits
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 30"}
SUN_DIST:         67.85 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      132.00d {+08h 47m 59s}  +22.32d {+22d 19' 07"}
MOON_DIST:        74.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.73,  0.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      176.73,-59.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.  
COMMENTS:        There is a bright star (mag=5.01) 9.23 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:06:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1064421,   Seg_Num: 0
POINT_RA:        143.576d {+09h 34m 18s} (J2000)
POINT_DEC:       -51.429d {-51d 25' 42"} (J2000)
ROLL:            354.336d
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82808.74 SOD {23:00:08.74} UT,   180.2 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     650070036
X_OFFSET:        895 [pixels]
Y_OFFSET:        625 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1055
Y_GRB_POS:       785
BINNING_INDEX:   1
IM_URL:          sw01064421000msuni0208.fits
SUN_POSTN:       138.11d {+09h 12m 28s}  +16.14d {+16d 08' 29"}
SUN_DIST:         67.85 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      132.01d {+08h 48m 03s}  +22.32d {+22d 18' 55"}
MOON_DIST:        74.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.73,  0.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      176.73,-59.83 [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.  
COMMENTS:        There is a bright star (mag=5.01) 9.23 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:05:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1064421,   Seg_Num: 0
POINT_RA:        143.576d {+09h 34m 18s} (J2000)
POINT_DEC:       -51.429d {-51d 25' 42"} (J2000)
POINT_ROLL:      354.336d
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82808.74 SOD {23:00:08.74} UT,   180.2 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.678
N_STARS:         84
X_OFFSET:        560 [pixels]
Y_OFFSET:        376 [pixels]
X_MAX:           1519 [pixels]
Y_MAX:           1335 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw01064421000msufc0180.fits
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 30"}
SUN_DIST:         67.85 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      132.00d {+08h 48m 00s}  +22.32d {+22d 19' 05"}
MOON_DIST:        74.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.73,  0.31 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      176.73,-59.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.  
COMMENTS:        There is a bright star (mag=5.01) 9.23 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Aug 21 23:00:33 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1064421,   Seg_Num: 0
GRB_RA:          143.5366d {+09h 34m 08.78s} (J2000),
                 143.7239d {+09h 34m 53.72s} (current),
                 143.1036d {+09h 32m 24.86s} (1950)
GRB_DEC:         -51.4028d {-51d 24' 10.0"} (J2000),
                 -51.4996d {-51d 29' 58.6"} (current),
                 -51.1795d {-51d 10' 46.2"} (1950)
GRB_ERROR:       5.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.31e-09 [erg/cm2/sec]
GRB_SIGNIF:      8.00 [sigma]
IMG_START_DATE:  19433 TJD;   219 DOY;   21/08/07
IMG_START_TIME:  82805.59 SOD {23:00:05.59} UT,   177.1 [sec] since BAT Trigger Time
TAM[0-3]:        327.66 237.17 261.58 243.37
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       138.11d {+09h 12m 27s}  +16.14d {+16d 08' 33"}
SUN_DIST:         67.82 [deg]   Sun_angle= -0.4 [hr] (East of Sun)
MOON_POSTN:      131.96d {+08h 47m 50s}  +22.33d {+22d 19' 36"}
MOON_DIST:        74.55 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      274.69,  0.32 [deg] galactic lon,lat of the burst
ECL_COORDS:      176.66,-59.83 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.63 arcmin from the BAT position.  
COMMENTS:        There is a bright star (mag=5.01) 8.85 arcmin from the XRT position.

GCN Circular #30609
The Fermi GBM team reports the detection of a likely LONG GRB
At 22:55:24 UT on 7 Aug 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210807C (trigger 650069729.307352 / 210807955).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 147.6, Dec = -51.4 (J2000 degrees, equivalent to J2000 09h 50m, -51d 23'), with a statistical uncertainty of 1.7 degrees.
The angle from the Fermi LAT boresight is 60.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_skymap_all_bn210807955.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_healpix_all_bn210807955.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210807955/quicklook/glg_lc_medres34_bn210807955.gif
GCN Circular #30610
A. Y. Lien (GSFC/UMBC), C. Gronwall (PSU), J.D. Gropp (PSU), N. J. Klingler (GSFC/UMBC/CRESSTII), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team:
At 22:57:08 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210807C (trigger=1064421). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 143.551, -51.409 which is
```
   RA(J2000) = 09h 34m 12s
   Dec(J2000) = -51d 24' 31"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Although the lightcurve before T+8s is not currently available due to a telemetry dropout, the later lightcurve shows a complex structure extending at least to T+90s. The peak count rate in the available lightcurve was ~800 counts/sec (15-350 keV), at ~20 sec after the trigger.
The XRT began observing the field at 23:00:05.5 UT, 177.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 143.53455, -51.40237 which is equivalent to:
```
   RA(J2000)  = 09h 34m 08.29s
   Dec(J2000) = -51d 24' 08.5"
```
with an uncertainty of 7.1 arcseconds (radius, 90% containment). This location is 43 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data does not constrain the column density.
The initial flux in the 2.5 s image was 2.31e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 250 seconds with the V filter starting 180 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18.0 mag. No correction has been made for the large, but uncertain, extinction expected.
Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular #30611
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 GRB210807.96 (trigger No 1064421,09h 34m 12.24s , -51d 24m 32.4s, R=0.05) errorbox 55 sec after notice time and 171 sec after trigger time at 2021-08-07 22:59:59 UT, with upper limit up to 17.0 mag. Observations started at twilight. The observations began at zenith distance = 66 deg. The sun altitude is -12.4 deg.
The galactic latitude b = 0 deg., longitude l = 275 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1683851
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     181 |         MASTER-OAFA |   C |    20 | 16.6 |        
     226 |         MASTER-OAFA |   C |    30 | 16.8 |        
     280 |         MASTER-OAFA |   C |    40 | 17.0 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.

GCN Circular #30612
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) started inspect of the Fermi GRB 210807C ( Fermi GBM team, GCN 30609) errorbox 114 sec after notice time and 206 sec after trigger time at 2021-08-07 22:58:50 UT, with upper limit up to 18.6 mag. Observations started at twilight. The observations began at zenith distance = 64 deg. The sun altitude is -12.1 deg.
MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 210807C errorbox 15419 sec after notice time and 15511 sec after trigger time at 2021-08-08 03:13:56 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 81 deg. The sun altitude is -27.5 deg.
The galactic latitude b = 2 deg., longitude l = 277 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1683879
We obtain a following upper limits.

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     222 | 2021-08-07 22:58:50 |         MASTER-OAFA | (09h 51m 36.60s , -48d 08m 16.7s) |   C |    30 | 16.4 |        
     285 | 2021-08-07 22:59:59 |         MASTER-OAFA | (09h 32m 30.94s , -50d 38m 28.4s) |   C |    20 | 16.6 |        
     320 | 2021-08-07 22:59:59 |         MASTER-OAFA | (09h 32m 30.95s , -50d 38m 28.4s) |   C |    90 | 17.3 |  Coadd 
     615 | 2021-08-07 22:59:59 |         MASTER-OAFA | (09h 32m 30.93s , -50d 38m 28.5s) |   C |   680 | 18.3 |  Coadd 
     330 | 2021-08-07 23:00:39 |         MASTER-OAFA | (09h 32m 26.75s , -50d 36m 58.8s) |   C |    30 | 16.8 |        
     384 | 2021-08-07 23:01:28 |         MASTER-OAFA | (09h 32m 26.54s , -50d 38m 17.9s) |   C |    40 | 17.0 |        
     449 | 2021-08-07 23:02:28 |         MASTER-OAFA | (09h 32m 28.68s , -50d 37m 04.2s) |   C |    50 | 17.1 |        
     524 | 2021-08-07 23:02:28 |         MASTER-OAFA | (09h 32m 28.68s , -50d 37m 04.3s) |   C |   200 | 17.8 |  Coadd 
     528 | 2021-08-07 23:03:37 |         MASTER-OAFA | (09h 32m 22.55s , -50d 37m 43.5s) |   C |    70 | 17.3 |        
     622 | 2021-08-07 23:05:06 |         MASTER-OAFA | (09h 32m 22.46s , -50d 36m 42.4s) |   C |    80 | 17.5 |        
     732 | 2021-08-07 23:06:46 |         MASTER-OAFA | (09h 32m 28.12s , -50d 37m 41.4s) |   C |   100 | 17.7 |        
     877 | 2021-08-07 23:06:46 |         MASTER-OAFA | (09h 32m 28.14s , -50d 37m 41.5s) |   C |   390 | 18.3 |  Coadd 
     866 | 2021-08-07 23:08:45 |         MASTER-OAFA | (09h 32m 22.16s , -50d 38m 40.7s) |   C |   130 | 17.9 |        
    1030 | 2021-08-07 23:11:14 |         MASTER-OAFA | (09h 32m 29.66s , -50d 38m 09.7s) |   C |   160 | 18.0 |        
    1220 | 2021-08-07 23:14:14 |         MASTER-OAFA | (09h 32m 25.67s , -50d 37m 04.8s) |   C |   180 | 18.2 |        
    1400 | 2021-08-07 23:14:14 |         MASTER-OAFA | (09h 32m 25.67s , -50d 37m 04.8s) |   C |   540 | 18.6 |  Coadd 
    1420 | 2021-08-07 23:17:34 |         MASTER-OAFA | (09h 32m 25.60s , -50d 38m 34.9s) |   C |   180 | 18.2 |        
    1619 | 2021-08-07 23:20:53 |         MASTER-OAFA | (09h 32m 28.21s , -50d 36m 47.5s) |   C |   180 | 18.3 |        
    1819 | 2021-08-07 23:24:13 |         MASTER-OAFA | (09h 32m 22.92s , -50d 37m 36.2s) |   C |   180 | 18.2 |        
    1999 | 2021-08-07 23:24:13 |         MASTER-OAFA | (09h 32m 22.92s , -50d 37m 36.2s) |   C |   540 | 18.6 |  Coadd 
    2019 | 2021-08-07 23:27:32 |         MASTER-OAFA | (09h 32m 22.25s , -50d 36m 35.5s) |   C |   180 | 18.3 |        
    2218 | 2021-08-07 23:30:52 |         MASTER-OAFA | (09h 32m 28.88s , -50d 37m 34.8s) |   C |   180 | 18.3 |        
    2417 | 2021-08-07 23:34:11 |         MASTER-OAFA | (09h 32m 22.28s , -50d 38m 34.3s) |   C |   180 | 18.2 |        
    2597 | 2021-08-07 23:34:11 |         MASTER-OAFA | (09h 32m 22.29s , -50d 38m 34.3s) |   C |   540 | 18.6 |  Coadd 
    2617 | 2021-08-07 23:37:31 |         MASTER-OAFA | (09h 32m 29.11s , -50d 38m 18.2s) |   C |   180 | 18.2 |        
    2816 | 2021-08-07 23:40:50 |         MASTER-OAFA | (09h 32m 25.11s , -50d 36m 58.5s) |   C |   180 | 18.3 |        
    3016 | 2021-08-07 23:44:09 |         MASTER-OAFA | (09h 32m 25.02s , -50d 38m 21.0s) |   C |   180 | 18.3 |        
    3196 | 2021-08-07 23:44:09 |         MASTER-OAFA | (09h 32m 25.02s , -50d 38m 21.0s) |   C |   540 | 18.5 |  Coadd 
    3215 | 2021-08-07 23:47:29 |         MASTER-OAFA | (09h 32m 28.03s , -50d 36m 52.9s) |   C |   180 | 18.2 |        
    3415 | 2021-08-07 23:50:49 |         MASTER-OAFA | (09h 32m 21.71s , -50d 37m 32.1s) |   C |   180 | 18.2 |        
    3614 | 2021-08-07 23:54:08 |         MASTER-OAFA | (09h 32m 21.47s , -50d 36m 31.4s) |   C |   180 | 18.1 |        
    3794 | 2021-08-07 23:54:08 |         MASTER-OAFA | (09h 32m 21.47s , -50d 36m 31.5s) |   C |   540 | 18.5 |  Coadd 
    3814 | 2021-08-07 23:57:27 |         MASTER-OAFA | (09h 32m 27.57s , -50d 37m 32.7s) |   C |   180 | 17.9 |        
    4013 | 2021-08-08 00:00:47 |         MASTER-OAFA | (09h 32m 20.35s , -50d 38m 40.0s) |   C |   180 | 18.1 |        
    4212 | 2021-08-08 00:04:06 |         MASTER-OAFA | (09h 32m 27.14s , -50d 38m 22.6s) |   C |   180 | 18.1 |        
    4392 | 2021-08-08 00:04:06 |         MASTER-OAFA | (09h 32m 27.14s , -50d 38m 22.6s) |   C |   540 | 18.5 |  Coadd 
    4412 | 2021-08-08 00:07:26 |         MASTER-OAFA | (09h 32m 23.81s , -50d 36m 49.8s) |   C |   180 | 18.1 |        
    4612 | 2021-08-08 00:10:46 |         MASTER-OAFA | (09h 32m 23.52s , -50d 38m 37.4s) |   C |   180 | 18.1 |        
    4811 | 2021-08-08 00:14:05 |         MASTER-OAFA | (09h 32m 25.80s , -50d 36m 50.7s) |   C |   180 | 18.1 |        
    5330 | 2021-08-08 00:22:44 |         MASTER-OAFA | (09h 32m 23.46s , -50d 36m 07.4s) |   C |   180 | 17.6 |        
    5847 | 2021-08-08 00:31:20 |         MASTER-OAFA | (09h 32m 22.91s , -50d 38m 05.8s) |   C |   180 | 17.5 |        
    6366 | 2021-08-08 00:40:00 |         MASTER-OAFA | (09h 32m 21.93s , -50d 36m 57.0s) |   C |   180 | 17.2 |        
    6884 | 2021-08-08 00:48:38 |         MASTER-OAFA | (09h 32m 25.05s , -50d 36m 50.2s) |   C |   180 | 17.2 |        
    7402 | 2021-08-08 00:57:16 |         MASTER-OAFA | (09h 32m 16.96s , -50d 36m 40.0s) |   C |   180 | 16.9 |        
    7921 | 2021-08-08 01:05:55 |         MASTER-OAFA | (09h 32m 16.80s , -50d 38m 40.1s) |   C |   180 | 16.7 |        
    8437 | 2021-08-08 01:14:31 |         MASTER-OAFA | (09h 32m 17.73s , -50d 36m 54.2s) |   C |   180 | 16.6 |        
    8956 | 2021-08-08 01:23:10 |         MASTER-OAFA | (09h 32m 20.07s , -50d 36m 39.2s) |   C |   180 | 16.1 |        
    9475 | 2021-08-08 01:31:49 |         MASTER-OAFA | (09h 32m 10.94s , -50d 36m 17.5s) |   C |   180 | 14.0 |        
   15602 | 2021-08-08 03:13:56 |         MASTER-SAAO | (09h 34m 22.59s , -51d 21m 56.9s) |   C |   180 | 17.5 |

Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.

GCN Circular #30615
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 722 s of XRT Photon Counting mode data and 1 UVOT images for GRB 210807C, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 143.53386, -51.40105 which is equivalent to:
```
RA (J2000): 09h 34m 8.13s
Dec (J2000): -51d 24' 03.8"
```
with an uncertainty of 2.0 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #30619
GRB 210807C: Swift/UVOT Upper Limits
S. J. LaPorte (PSU) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210807C 180 s after the BAT trigger (Lien et al., GCN Circ. 30610). No optical afterglow consistent with the XRT position (Lien et al. GCN Circ. 30610) 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 initial exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

v                  180          852          596         >19.4
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 3.076 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #30620
S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 22:55:24.31 UT on 7 July 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 210807C (trigger 650069729 / 210807955) which was also detected by the Swift/BAT (Lien et al. 2021, GCN 30610). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 61 degrees.
The GBM light curve consists of multiple peaks followed by some extended emission with a duration (T90) of about 125 s (50-300 keV). The time-averaged spectrum from T0 s to T0+94.2 s is best fit by a Band function, with Epeak = 170 +/- 28 keV, alpha = -1.08 +/- 0.06 and beta = -1.61 +/- 0.01.
The event fluence (10-1000 keV) in this time interval is (56.43 +/- 0.54)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+8.64 s in the 10-1000 keV band is 7.2 +/- 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 #30621
P.A. Evans (U. Leicester) and A. Y. Lien (GSFC/UMBC) reports on behalf of the Swift-XRT team:
We have analysed 5.8 ks of XRT data for GRB 210807C (Lien et al. GCN Circ. 30610), from 183 s to 56.8 ks after the BAT trigger. The data comprise 203 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 30615).
The light curve can be modelled with a power-law decay with a decay index of alpha=3.11 (+2.96, -0.22), followed by a break at T0+420.7 (+18.1, -165.2) s to a decay of 1.32 (+0.09, -0.07).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.28 (+0.15, -0.14). The best-fitting absorption column is 4.9 (+/-0.4) x 10^22 cm^-2, in excess of the Galactic value of 8.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.5 (+/-0.6) and a best-fitting absorption column of 6.0 (+1.8, -1.5) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 7.6 x 10^-11 (4.1 x 10^-10) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     6.0 (+1.8, -1.5) x 10^22 cm^-2
Galactic foreground: 8.5 x 10^21 cm^-2
Excess significance: 5.5 sigma
Photon index:	     2.5 (+/-0.6)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01064421.
This circular is an official product of the Swift-XRT team.
GCN Circular #30625
S. D. Barthelmy (GSFC), J. R. Cummings (CPI), 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 210807C (trigger #1064421) (Lien et al., GCN Circ. 30610). The BAT ground-calculated position is RA, Dec = 143.540, -51.409 deg which is
```
   RA(J2000)  =  09h 34m 09.7s
   Dec(J2000) = -51d 24' 32.8"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 20%.
The BAT light curve showed a complex structure with a duration of about ~100 sec. T90 (15-350 keV) is 89.97 +- 6.26 sec (estimated error including systematics).
The time-averaged spectrum from T-31.36 to T+78.57 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.65 +- 0.06. The fluence in the 15-150 keV band is 1.2 +- 0.0 x 10^-05 erg/cm2. The 1-sec peak photon flux measured from T-24.22 sec in the 15-150 keV band is 4.0 +- 0.7 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1064421/BA/

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Jochen Greiner, last update: 10-Aug-2021 [Disclaimer]