Gamma-ray Burst 200925B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 21:50:49 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     997453,   Seg_Num: 0
GRB_RA:          246.851d {+16h 27m 24s} (J2000),
                 246.602d {+16h 26m 24s} (current),
                 247.466d {+16h 29m 52s} (1950)
GRB_DEC:         +78.394d {+78d 23' 39"} (J2000),
                 +78.348d {+78d 20' 55"} (current),
                 +78.502d {+78d 30' 08"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2918 [cnts]    Image_Peak=148 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   147     E_range: 25-100 keV
BKG_INTEN:       18121 [cnts]
BKG_TIME:        78622.30 SOD {21:50:22.30} UT
BKG_DUR:         8 [sec]
GRB_DATE:        19117 TJD;   269 DOY;   20/09/25
GRB_TIME:        78637.02 SOD {21:50:37.02} UT
GRB_PHI:         126.29 [deg]
GRB_THETA:        29.05 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.87 [sigma]
IMAGE_SIGNIF:    7.68 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -2  +0  +0  -6  +0 
SUN_POSTN:       183.01d {+12h 12m 03s}   -1.30d {-01d 18' 16"}
SUN_DIST:         86.13 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.21d {+19h 52m 51s}  -23.59d {-23d 35' 28"}
MOON_DIST:       106.08 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      109.78, 76.48 [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 = 147.39,20.24 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 21:52:05 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.803d {+16h 27m 13s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78715.38 SOD {21:51:55.38} UT,   78.4 [sec] since BAT Trigger Time
COUNTS:          2    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:     Tue 22 Sep 20 12:14:01 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     997024,   Seg_Num: 0
POINT_RA:        296.922d {+19h 47m 41s} (J2000)
POINT_DEC:       -55.211d {-55d 12' 39"} (J2000)
ROLL:            247.347d
IMG_START_DATE:  19114 TJD;   266 DOY;   20/09/22
IMG_START_TIME:  43692.08 SOD {12:08:12.08} UT,   85.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     622469317
X_OFFSET:        670 [pixels]
Y_OFFSET:        952 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       830
Y_GRB_POS:       1112
BINNING_INDEX:   1
IM_URL:          sw00997024000msuni0111.fits
SUN_POSTN:       179.96d {+11h 59m 49s}   +0.02d {+00d 01' 10"}
SUN_DIST:        105.25 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
MOON_POSTN:      248.40d {+16h 33m 36s}  -20.57d {-20d 34' 09"}
MOON_DIST:        50.23 [deg]
MOON_ILLUM:      33 [%]
GAL_COORDS:      342.59,-29.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      288.04,-33.44 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 22 Sep 20 12:14:11 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     997024,   Seg_Num: 0
POINT_RA:        296.922d {+19h 47m 41s} (J2000)
POINT_DEC:       -55.211d {-55d 12' 39"} (J2000)
ROLL:            247.347d
IMG_START_DATE:  19114 TJD;   266 DOY;   20/09/22
IMG_START_TIME:  43692.08 SOD {12:08:12.08} UT,   85.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     622469317
X_OFFSET:        670 [pixels]
Y_OFFSET:        952 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       830
Y_GRB_POS:       1112
BINNING_INDEX:   1
IM_URL:          sw00997024000msuni0111.fits
SUN_POSTN:       179.96d {+11h 59m 49s}   +0.02d {+00d 01' 09"}
SUN_DIST:        105.25 [deg]   Sun_angle= -7.8 [hr] (East of Sun)
MOON_POSTN:      248.40d {+16h 33m 37s}  -20.57d {-20d 34' 11"}
MOON_DIST:        50.23 [deg]
MOON_ILLUM:      33 [%]
GAL_COORDS:      342.59,-29.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      288.04,-33.44 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 21:55:45 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     997453,   Seg_Num: 0
GRB_RA:          246.7887d {+16h 27m 09.28s} (J2000),
                 246.5395d {+16h 26m 09.48s} (current),
                 247.4024d {+16h 29m 36.58s} (1950)
GRB_DEC:         +78.3903d {+78d 23' 25.0"} (J2000),
                 +78.3446d {+78d 20' 40.4"} (current),
                 +78.4987d {+78d 29' 55.2"} (1950)
GRB_ERROR:       4.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78724.00 SOD {21:52:04.00} UT,   87.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       183.02d {+12h 12m 04s}   -1.31d {-01d 18' 21"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.26d {+19h 53m 02s}  -23.59d {-23d 35' 10"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.51 [deg] galactic lon,lat of the burst
ECL_COORDS:      109.83, 76.48 [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 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 21:54:29 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     997453,   Seg_Num: 0
GRB_RA:          246.851d {+16h 27m 24s} (J2000),
                 246.602d {+16h 26m 24s} (current),
                 247.466d {+16h 29m 52s} (1950)
GRB_DEC:         +78.394d {+78d 23' 39"} (J2000),
                 +78.348d {+78d 20' 55"} (current),
                 +78.502d {+78d 30' 08"} (1950)
GRB_DATE:        19117 TJD;   269 DOY;   20/09/25
GRB_TIME:        78637.02 SOD {21:50:37.02} UT
TRIGGER_INDEX:   147
GRB_PHI:         126.29 [deg]
GRB_THETA:        29.05 [deg]
DELTA_TIME:      -31.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.87 [sigma]
IMAGE_SIGNIF:    7.68 [sigma]
LC_URL:          sw00997453000msb.lc
SUN_POSTN:       183.01d {+12h 12m 03s}   -1.31d {-01d 18' 19"}
SUN_DIST:         86.13 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.25d {+19h 52m 59s}  -23.59d {-23d 35' 15"}
MOON_DIST:       106.08 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      109.78, 76.48 [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 = 147.39,20.24 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 21:57:03 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.803d {+16h 27m 13s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
ROLL:            244.016d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78718.74 SOD {21:51:58.74} UT,   81.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     622763544
X_OFFSET:        711 [pixels]
Y_OFFSET:        950 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1110
BINNING_INDEX:   1
IM_URL:          sw00997453000msuni0107.fits
SUN_POSTN:       183.02d {+12h 12m 04s}   -1.31d {-01d 18' 22"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.27d {+19h 53m 05s}  -23.59d {-23d 35' 05"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.67, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.84, 76.48 [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:     Fri 25 Sep 20 21:55:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.803d {+16h 27m 13s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
POINT_ROLL:      244.016d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78718.74 SOD {21:51:58.74} UT,   81.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.876
N_STARS:         26
X_OFFSET:        392 [pixels]
Y_OFFSET:        631 [pixels]
X_MAX:           1351 [pixels]
Y_MAX:           1590 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00997453000msufc0081.fits
SUN_POSTN:       183.02d {+12h 12m 04s}   -1.31d {-01d 18' 21"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.26d {+19h 53m 02s}  -23.59d {-23d 35' 11"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.67, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.84, 76.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 22:03:55 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.791d {+16h 27m 10s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
POINT_ROLL:      244.004d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78930.92 SOD {21:55:30.92} UT,   293.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.130
N_STARS:         48
X_OFFSET:        152 [pixels]
Y_OFFSET:        391 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1830 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00997453000msufc0293.fits
SUN_POSTN:       183.02d {+12h 12m 05s}   -1.31d {-01d 18' 29"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.34d {+19h 53m 21s}  -23.58d {-23d 34' 41"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.85, 76.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 22:04:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.791d {+16h 27m 10s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
POINT_ROLL:      244.004d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78930.92 SOD {21:55:30.92} UT,   293.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.130
N_STARS:         48
X_OFFSET:        152 [pixels]
Y_OFFSET:        391 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1830 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00997453000msufc0293.fits
SUN_POSTN:       183.02d {+12h 12m 05s}   -1.31d {-01d 18' 29"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.34d {+19h 53m 22s}  -23.58d {-23d 34' 39"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.85, 76.48 [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:     Fri 25 Sep 20 22:04:32 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     997453,   Seg_Num: 0
GRB_RA:          246.7858d {+16h 27m 08.59s} (J2000),
                 246.5366d {+16h 26m 08.78s} (current),
                 247.3995d {+16h 29m 35.87s} (1950)
GRB_DEC:         +78.3902d {+78d 23' 24.7"} (J2000),
                 +78.3445d {+78d 20' 40.0"} (current),
                 +78.4986d {+78d 29' 54.9"} (1950)
GRB_ERROR:       2.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78724.00 SOD {21:52:04.00} UT,   87.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       183.02d {+12h 12m 05s}   -1.31d {-01d 18' 29"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.34d {+19h 53m 23s}  -23.58d {-23d 34' 38"}
MOON_DIST:       106.10 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.51 [deg] galactic lon,lat of the burst
ECL_COORDS:      109.83, 76.48 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 21:55:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.803d {+16h 27m 13s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
POINT_ROLL:      244.016d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78718.74 SOD {21:51:58.74} UT,   81.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.876
N_STARS:         26
X_OFFSET:        392 [pixels]
Y_OFFSET:        631 [pixels]
X_MAX:           1351 [pixels]
Y_MAX:           1590 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00997453000msufc0081.fits
SUN_POSTN:       183.02d {+12h 12m 04s}   -1.31d {-01d 18' 21"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.26d {+19h 53m 03s}  -23.59d {-23d 35' 10"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.67, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.84, 76.48 [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:     Fri 25 Sep 20 21:57:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.803d {+16h 27m 13s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
ROLL:            244.016d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78718.74 SOD {21:51:58.74} UT,   81.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     622763544
X_OFFSET:        711 [pixels]
Y_OFFSET:        950 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1110
BINNING_INDEX:   1
IM_URL:          sw00997453000msuni0107.fits
SUN_POSTN:       183.02d {+12h 12m 04s}   -1.31d {-01d 18' 22"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.27d {+19h 53m 06s}  -23.58d {-23d 35' 04"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.67, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.84, 76.48 [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:     Fri 25 Sep 20 22:10:10 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.791d {+16h 27m 10s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 02"} (J2000)
POINT_ROLL:      244.004d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  79508.50 SOD {22:05:08.50} UT,   871.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.553
N_STARS:         129
X_OFFSET:        152 [pixels]
Y_OFFSET:        391 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1830 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00997453000msufc0871.fits
SUN_POSTN:       183.02d {+12h 12m 06s}   -1.31d {-01d 18' 35"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.40d {+19h 53m 36s}  -23.57d {-23d 34' 18"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.67, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.85, 76.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Sep 20 22:05:28 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.791d {+16h 27m 10s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
ROLL:            244.004d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78930.92 SOD {21:55:30.92} UT,   293.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     622763756
X_OFFSET:        711 [pixels]
Y_OFFSET:        950 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1110
BINNING_INDEX:   1
IM_URL:          sw00997453000msuni0319.fits
SUN_POSTN:       183.02d {+12h 12m 05s}   -1.31d {-01d 18' 30"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.35d {+19h 53m 25s}  -23.58d {-23d 34' 35"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.85, 76.48 [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:     Fri 25 Sep 20 22:05:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.791d {+16h 27m 10s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 03"} (J2000)
ROLL:            244.004d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  78930.92 SOD {21:55:30.92} UT,   293.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     622763756
X_OFFSET:        711 [pixels]
Y_OFFSET:        950 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1110
BINNING_INDEX:   1
IM_URL:          sw00997453000msuni0319.fits
SUN_POSTN:       183.02d {+12h 12m 05s}   -1.31d {-01d 18' 30"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.35d {+19h 53m 25s}  -23.58d {-23d 34' 35"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.68, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.85, 76.48 [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:     Fri 25 Sep 20 22:11:31 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     997453,   Seg_Num: 0
POINT_RA:        246.791d {+16h 27m 10s} (J2000)
POINT_DEC:       +78.384d {+78d 23' 02"} (J2000)
ROLL:            244.004d
IMG_START_DATE:  19117 TJD;   269 DOY;   20/09/25
IMG_START_TIME:  79508.50 SOD {22:05:08.50} UT,   871.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     622764334
X_OFFSET:        711 [pixels]
Y_OFFSET:        950 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1110
BINNING_INDEX:   1
IM_URL:          sw00997453000msuni0897.fits
SUN_POSTN:       183.03d {+12h 12m 06s}   -1.31d {-01d 18' 36"}
SUN_DIST:         86.12 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      298.41d {+19h 53m 39s}  -23.57d {-23d 34' 13"}
MOON_DIST:       106.09 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      111.67, 33.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      109.85, 76.48 [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 #28498
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University)
MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB200925.91 (trigger No 997453,16h 27m 24.24s , +78d 23m 38.4s, R=0.05) errorbox 14 sec after notice time and 58 sec after trigger time at 2020-09-25 21:51:35 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 53 deg. The sun altitude is -47.0 deg.
The galactic latitude b = 34 deg., longitude l = 112 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1449109
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

      64 |      MASTER-Tavrida |   C |    10 | 17.1 |        
      99 |      MASTER-Tavrida |   C |    20 | 17.9 |        
     139 |      MASTER-Tavrida |   C |    20 | 17.9 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #28499
S. B. Cenko (GSFC), C. Gronwall (PSU), J.D. Gropp (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
At 21:50:37 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200925B (trigger=997453). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 246.851, +78.394 which is
```
   RA(J2000) = 16h 27m 24s
   Dec(J2000) = +78d 23' 39"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 40 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began observing the field at 21:51:55.3 UT, 78.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 246.78990, 78.39033 which is equivalent to:
```
   RA(J2000)  = 16h 27m 09.58s
   Dec(J2000) = +78d 23' 25.2"
```
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 46 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 gives a column density consistent with the Galactic value of 4.59 x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 81 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.04.
Burst Advocate for this burst is S. B. Cenko (brad.cenko 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 #28500
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 200925B, we find an enhanced XRT position of the afterglow: RA, Dec: 246.7868, 78.3904 which is equivalent to:
```
   RA (J2000)  = 16 27 08.83   
   Dec (J2000) = +78 23 25.5   
```
with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/997453.
Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular #28501
A. de Ugarte Postigo (HETH/IAA-CSIS, DARK/NBI), D. A. Kann, C. C. Thone, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), and F. Aceituno (IAA-CSIC) report:
We observed the location of the Swift GRB 200906A (Cenko et al., GCN #28499) with the 1.5m telescope of the Observatorio Sierra Nevada, in Granada, Spain. We obtained a 300 s image each in the BVRc bands and multiple 100 s images in Ic, beginning 2020-09-25 22:27:07 UT.
We detect a source in all filters at
```
RA (J2000) = 16:27:08.50
Dec. (J2000) = +78:23:24.9
```
with an error of 0".5, within the UVOT-enhanced XRT position (Evans, GCN #28500). We note this source is also clearly detected in the initial Swift UVOT white finding chart, at a significantly brighter magnitude relative to the nearby field star.
This strongly suggests the source is fading and is therefore the afterglow of GRB 200925B.
At 0.034294 days after the GRB, we measure r' = 19.46 +/- 0.1 (AB magnitude) vs. nearby SDSS field stars.
GCN Circular #28502
V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, 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),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
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),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University)
MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB200925A (trigger No 997453,16h 27m 24.24s , +78d 23m 38.4s, R=0.05) errorbox 14 sec after notice time and 58 sec after trigger time at 2020-09-25 21:51:35 UT, with upper limit up to 18.4 mag. The observations began at zenith distance = 53 deg. The sun altitude is -47.0 deg.
On our 4-th (40s exposure) set , obtained 229 sec after tigger time at 2020-09-25 21:54:16 UT, we found an optical transient within Swift error-box (ra=246.851 dec=+78.394 r=0.05).
```
  T-Tmid      Date      Time       Expt.        Ra                Dec          Mag
---------|---------------------|-------|-----------------|-----------------|-----
      229   2020-09-25 21:54:16      40   (246.7866 d, +78.3896 d)   17.9
```
The OT position in within enhanced XRT position (GCN 28500) and is coincident with OSN afterglow candidate position (A. de Ugarte Postigo et al, GCN 28501)
The 5-sigma upper limit has been about 18.4 mag The message may be cited.
GCN Circular #28503
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 1704 s of XRT Photon Counting mode data and 1 UVOT images for GRB 200925B, 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 = 246.78522, +78.39052 which is equivalent to:
```
RA (J2000): 16h 27m 8.45s
Dec (J2000): +78d 23' 25.9"
```
with an uncertainty of 1.8 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 #28506
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200925B (trigger #997453) (Cenko, et al., GCN Circ. 28499). The BAT ground-calculated position is RA, Dec = 246.892, 78.393 deg which is
```
  RA(J2000)  =  16h 27m 34.1s 
  Dec(J2000) = +78d 23' 33.5" 
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%.
The mask-weighted light curve shows two peaks, the first beginning ~T-2 sec, peaking at T+5 sec, and decaying by T+12 sec. The second, weaker, peak runs from T+16 to T+22 sec. T90 (15-350 keV) is 18.25 +- 0.97 sec (estimated error including systematics).
The time-averaged spectrum from T+0.20 to T+19.59 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.01 +- 0.14. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+4.38 sec in the 15-150 keV band is 3.0 +- 0.3 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/997453/BA/
GCN Circular #28507
S. R. Oates (U.Birmingham) and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 200925B 82 s after the BAT trigger (Cenko et al., GCN Circ. 28499). A source consistent with the XRT position (Beardmore et al. GCN Circ. 28503) and the optical position reported by the OSN (de Ugarte Postigo et al., GCN Circ. 28501) and MASTER (Lipunov et al., GCN Circ. 28502) is detected in the initial UVOT exposures.
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white (FC)      82          232           147        19.80 +/- 0.20
white           574         1714          264        20.77 +/- 0.37
v               623         1763          136        >18.9
b               549         1689          117        >19.6
u (FC)          294         544           246        >19.7
u               294         1663          343        >19.9
w1              672         1813          136        >19.0
m2              1249        1441           39        >17.7
w2              599         1739          117        >18.9
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #28508
B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and S.B. Cenko report on behalf of the Swift-XRT team:
We have analysed 5.1 ks of XRT data for GRB 200925B (Cenko et al. GCN Circ. 28499), from 87 s to 47.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 28500). The late-time light curve (from T0+29.2 ks) is consistent with a constant source of mean count rate 1.3e-01 ct/sec. A power-law fit gives an index of 1.0 (+/-1.2).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.12 (+0.19, -0.18). The best-fitting absorption column is 7.5 (+4.4, -2.9) x 10^20 cm^-2, consistent with the Galactic value of 4.6 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 3.1 x 10^-11 (3.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     7.5 (+4.4, -2.9) x 10^20 cm^-2
Galactic foreground: 4.6 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.12 (+0.19, -0.18)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00997453.
This circular is an official product of the Swift-XRT team.
GCN Circular #28511
B. Grossan (UCB, NU) , Z. Maksut (NU), A. Kim (NU), M. Krugov (FAI), G. F. Smoot (HKUST, UCB, NU), E. Linder (UCB, NU), report on behalf of the Energetic Cosmos Laboratory:
The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) pointed at GRB200925B on receipt of an automated GCN / BAT position alert. We report measurements made with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32,14) instrument ***during commissioning phase*** and we note cautions with these measurements below.
Calibration with bright Pan-STARRS catalog I stars on our images, for our standard SDSS filters and 45 s co-added images yields, *without color corrections*, the following photometric values for the OT consistent with the position given in Evans et al. (GCN 28503):
```
#	tc-t0(s)	g'(mag) 	   r'(mag)     i'(mag)
--	---------	-----------	  -----------  ------------
1	67.5   	UL18.27     UL18.07 UL17.32
2      136.5   	UL18.15      18.62      17.94** 
3      181.5   	UL18.21      17.99      17.47
4      226.5   	UL18.25      18.09      17.63
5      271.5   	UL18.27      18.17      17.48
6      316.5   	UL18.31      18.26      17.70
7      361.5   	UL18.14      18.60      17.83
8      406.5   	UL18.17      18.55      17.87*

UL = 5 sigma upper limit
** = very large certainty, close to limit ; poor by-eye confirmation and aperture centering
* = large uncertainty ; poor by-eye confirmation and aperture centering
Other uncertainties are estimated at ~ 0.1 mag
tc-t0 = trigger time minus image center time.
```
The measurements suggest that the early emission peaked ~180 s after trigger.
We caution the reader that the BSTI instrument is in commissioning phase, with known imperfections, and we have not extensively tested our results, e.g. against other simultaneous measurements, or near our detection limits. Please also note that the times are approximate. We anticipate additional analysis in 15-30 days posted at http://ecl.nu.edu.kz/gamma-ray-burst/grb200925b. Some earlier images may have usable data.
```
----------------------------------
UCB = University of California, Berkeley, USA
NU = Nazarbayev University, Nur-Sultan, Kazakhstan
HKUST = Hong Kong University of Science and Technology
FAI = Fesenkov Astrophysical Institute, Kazakhstan 
```
The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.
GCN Circular #28512
A.P. Beardmore (U. Leicester) and S. B. Cenko (GSFC) report on behalf of the Swift-XRT team:
An additional 4.9 ks of Swift-XRT Photon Counting mode data have been collected on GRB 200925B (Cenko et al. GCN Circ. 28499, Sbarufatti et al. GCN Circ. 28508), bringing the total XRT exposure to 10 ks, from 87 s to 86.3 ks after the BAT trigger. The late time X-ray light curve from T0+29.2 ks to 86.3 ks is now decaying with a power-law decay slope of 1.1 +/- 0.4.
If the light curve continues to decay at the same rate than the predicted count rate at T0+3 days will be 3.4e-03 count/sec, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.05 x 10^-13 (1.28 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00997453.
This circular is an official product of the Swift-XRT team.

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Jochen Greiner, last update: 23-Oct-2020 [Disclaimer]