Gamma-ray Burst 210419A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 06:54:56 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1044032,   Seg_Num: 0
GRB_RA:           86.862d {+05h 47m 27s} (J2000),
                  86.875d {+05h 47m 30s} (current),
                  86.833d {+05h 47m 20s} (1950)
GRB_DEC:         -65.539d {-65d 32' 20"} (J2000),
                 -65.533d {-65d 31' 56"} (current),
                 -65.554d {-65d 33' 15"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1227 [image_cnts]
TRIGGER_DUR:     64.000 [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:        19323 TJD;   109 DOY;   21/04/19
GRB_TIME:        24821.12 SOD {06:53:41.12} UT
GRB_PHI:          98.71 [deg]
GRB_THETA:        21.15 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    8.15 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -2  +0  +0  -2  +0 
SUN_POSTN:        27.38d {+01h 49m 32s}  +11.28d {+11d 16' 34"}
SUN_DIST:         88.38 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.71d {+07h 18m 50s}  +25.39d {+25d 23' 10"}
MOON_DIST:        92.60 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.23,-31.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       37.29,-88.37 [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:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 88.56,-1.32 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 06:56:23 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1044032,   Seg_Num: 0
GRB_RA:           86.8529d {+05h 47m 24.6s} (J2000),
                  86.8660d {+05h 47m 27.8s} (current),
                  86.8227d {+05h 47m 17.4s} (1950)
GRB_DEC:         -65.5043d {-65d 30' 15.4"} (J2000),
                 -65.4978d {-65d 29' 52.0"} (current),
                 -65.5197d {-65d 31' 10.7"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       51 [cnts]
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24949.01 SOD {06:55:49.01} UT,   127.9 [sec] since BAT Trigger Time
CENTROID_X:      311.26,  raw= 311  [pixels]
CENTROID_Y:      253.47,  raw= 253  [pixels]
ROLL:            302.36 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -105.19
GRB_POS_XRT_Z:   9.10
IMAGE_URL:       sw01044032000msxps_rw.img
SUN_POSTN:        27.39d {+01h 49m 33s}  +11.28d {+11d 16' 35"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.72d {+07h 18m 54s}  +25.39d {+25d 23' 08"}
MOON_DIST:        92.57 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.19,-31.11 [deg] galactic lon,lat of the burst
ECL_COORDS:       38.12,-88.34 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 06:56:26 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1044032,   Seg_Num: 0
GRB_RA:           86.8529d {+05h 47m 24.6s} (J2000),
                  86.8660d {+05h 47m 27.8s} (current),
                  86.8227d {+05h 47m 17.4s} (1950)
GRB_DEC:         -65.5043d {-65d 30' 15.4"} (J2000),
                 -65.4978d {-65d 29' 52.0"} (current),
                 -65.5197d {-65d 31' 10.7"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       51 [cnts]
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24949.01 SOD {06:55:49.01} UT,   127.9 [sec] since BAT Trigger Time
CENTROID_X:      311.26,  raw= 311  [pixels]
CENTROID_Y:      253.47,  raw= 253  [pixels]
ROLL:            302.36 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -105.19
GRB_POS_XRT_Z:   9.10
IMAGE_URL:       sw01044032000msxps_rw.img
SUN_POSTN:        27.39d {+01h 49m 33s}  +11.28d {+11d 16' 35"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.72d {+07h 18m 54s}  +25.39d {+25d 23' 08"}
MOON_DIST:        92.57 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.19,-31.11 [deg] galactic lon,lat of the burst
ECL_COORDS:       38.12,-88.34 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 06:57:37 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1044032,   Seg_Num: 0
GRB_RA:           86.862d {+05h 47m 27s} (J2000),
                  86.875d {+05h 47m 30s} (current),
                  86.833d {+05h 47m 20s} (1950)
GRB_DEC:         -65.539d {-65d 32' 20"} (J2000),
                 -65.533d {-65d 31' 56"} (current),
                 -65.554d {-65d 33' 15"} (1950)
GRB_DATE:        19323 TJD;   109 DOY;   21/04/19
GRB_TIME:        24821.12 SOD {06:53:41.12} UT
TRIGGER_INDEX:   20000
GRB_PHI:          98.71 [deg]
GRB_THETA:        21.15 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    8.15 [sigma]
LC_URL:          sw01044032000msb.lc
SUN_POSTN:        27.39d {+01h 49m 33s}  +11.28d {+11d 16' 36"}
SUN_DIST:         88.38 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.74d {+07h 18m 57s}  +25.38d {+25d 23' 05"}
MOON_DIST:        92.60 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.23,-31.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       37.29,-88.37 [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 an image 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 = 88.56,-1.32 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 06:56:13 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1044032,   Seg_Num: 0
GRB_RA:           86.8529d {+05h 47m 24.69s} (J2000),
                  86.8660d {+05h 47m 27.83s} (current),
                  86.8227d {+05h 47m 17.44s} (1950)
GRB_DEC:         -65.5043d {-65d 30' 15.4"} (J2000),
                 -65.4978d {-65d 29' 52.0"} (current),
                 -65.5197d {-65d 31' 10.7"} (1950)
GRB_ERROR:       5.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.57e-09 [erg/cm2/sec]
GRB_SIGNIF:      7.14 [sigma]
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24949.01 SOD {06:55:49.01} UT,   127.9 [sec] since BAT Trigger Time
TAM[0-3]:        327.72 237.17 261.72 243.29
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        27.39d {+01h 49m 33s}  +11.28d {+11d 16' 35"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.72d {+07h 18m 53s}  +25.39d {+25d 23' 08"}
MOON_DIST:        92.57 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.19,-31.11 [deg] galactic lon,lat of the burst
ECL_COORDS:       38.12,-88.34 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.10 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 07:01:16 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.811d {+05h 47m 15s} (J2000)
POINT_DEC:       -65.528d {-65d 31' 40"} (J2000)
POINT_ROLL:      302.358d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24957.58 SOD {06:55:57.58} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.277
N_STARS:         142
X_OFFSET:        320 [pixels]
Y_OFFSET:        656 [pixels]
X_MAX:           1279 [pixels]
Y_MAX:           1615 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw01044032000msufc0136.fits
SUN_POSTN:        27.39d {+01h 49m 33s}  +11.28d {+11d 16' 39"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.77d {+07h 19m 05s}  +25.38d {+25d 22' 58"}
MOON_DIST:        92.60 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.11,-88.34 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 07:01:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.811d {+05h 47m 15s} (J2000)
POINT_DEC:       -65.528d {-65d 31' 40"} (J2000)
POINT_ROLL:      302.358d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24957.58 SOD {06:55:57.58} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.277
N_STARS:         142
X_OFFSET:        320 [pixels]
Y_OFFSET:        656 [pixels]
X_MAX:           1279 [pixels]
Y_MAX:           1615 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw01044032000msufc0136.fits
SUN_POSTN:        27.39d {+01h 49m 33s}  +11.28d {+11d 16' 39"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.77d {+07h 19m 06s}  +25.38d {+25d 22' 58"}
MOON_DIST:        92.60 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.11,-88.34 [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:     Mon 19 Apr 21 07:03:42 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.811d {+05h 47m 15s} (J2000)
POINT_DEC:       -65.528d {-65d 31' 40"} (J2000)
ROLL:            302.358d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24957.58 SOD {06:55:57.58} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     640508184
X_OFFSET:        867 [pixels]
Y_OFFSET:        1074 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1027
Y_GRB_POS:       1234
BINNING_INDEX:   1
IM_URL:          sw01044032000msuni0163.fits
SUN_POSTN:        27.39d {+01h 49m 34s}  +11.28d {+11d 16' 41"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.79d {+07h 19m 10s}  +25.38d {+25d 22' 54"}
MOON_DIST:        92.60 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.11,-88.34 [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:     Mon 19 Apr 21 07:03:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.811d {+05h 47m 15s} (J2000)
POINT_DEC:       -65.528d {-65d 31' 40"} (J2000)
ROLL:            302.358d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  24957.58 SOD {06:55:57.58} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     640508184
X_OFFSET:        867 [pixels]
Y_OFFSET:        1074 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1027
Y_GRB_POS:       1234
BINNING_INDEX:   1
IM_URL:          sw01044032000msuni0163.fits
SUN_POSTN:        27.39d {+01h 49m 34s}  +11.28d {+11d 16' 41"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.80d {+07h 19m 11s}  +25.38d {+25d 22' 53"}
MOON_DIST:        92.60 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.11,-88.34 [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:     Mon 19 Apr 21 07:08:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.806d {+05h 47m 13s} (J2000)
POINT_DEC:       -65.526d {-65d 31' 33"} (J2000)
POINT_ROLL:      302.360d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  25115.52 SOD {06:58:35.52} UT,   294.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.600
N_STARS:         118
X_OFFSET:        547 [pixels]
Y_OFFSET:        754 [pixels]
X_MAX:           1506 [pixels]
Y_MAX:           1713 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw01044032000msufc0294.fits
SUN_POSTN:        27.39d {+01h 49m 34s}  +11.28d {+11d 16' 46"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.84d {+07h 19m 22s}  +25.38d {+25d 22' 44"}
MOON_DIST:        92.61 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.12,-88.34 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 07:09:21 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.806d {+05h 47m 13s} (J2000)
POINT_DEC:       -65.526d {-65d 31' 33"} (J2000)
ROLL:            302.360d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  25115.52 SOD {06:58:35.52} UT,   294.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     640508342
X_OFFSET:        867 [pixels]
Y_OFFSET:        1074 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1027
Y_GRB_POS:       1234
BINNING_INDEX:   1
IM_URL:          sw01044032000msuni0321.fits
SUN_POSTN:        27.39d {+01h 49m 35s}  +11.28d {+11d 16' 46"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.85d {+07h 19m 23s}  +25.38d {+25d 22' 43"}
MOON_DIST:        92.61 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.12,-88.34 [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:     Mon 19 Apr 21 07:09:31 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.806d {+05h 47m 13s} (J2000)
POINT_DEC:       -65.526d {-65d 31' 33"} (J2000)
ROLL:            302.360d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  25115.52 SOD {06:58:35.52} UT,   294.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     640508342
X_OFFSET:        867 [pixels]
Y_OFFSET:        1074 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1027
Y_GRB_POS:       1234
BINNING_INDEX:   1
IM_URL:          sw01044032000msuni0321.fits
SUN_POSTN:        27.39d {+01h 49m 35s}  +11.28d {+11d 16' 46"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.85d {+07h 19m 23s}  +25.38d {+25d 22' 43"}
MOON_DIST:        92.61 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.12,-88.34 [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:     Mon 19 Apr 21 07:08:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1044032,   Seg_Num: 0
POINT_RA:         86.806d {+05h 47m 13s} (J2000)
POINT_DEC:       -65.526d {-65d 31' 33"} (J2000)
POINT_ROLL:      302.360d
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  25115.52 SOD {06:58:35.52} UT,   294.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.600
N_STARS:         118
X_OFFSET:        547 [pixels]
Y_OFFSET:        754 [pixels]
X_MAX:           1506 [pixels]
Y_MAX:           1713 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw01044032000msufc0294.fits
SUN_POSTN:        27.39d {+01h 49m 34s}  +11.28d {+11d 16' 46"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.84d {+07h 19m 22s}  +25.38d {+25d 22' 44"}
MOON_DIST:        92.61 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.22,-31.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       37.12,-88.34 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN Circular #29828
S. Laha (GSFC/UMBC/CRESST), E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), J. A. Kennea (PSU), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team:
At 06:53:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210419A (trigger=1044032). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 86.862, -65.539 which is
```
   RA(J2000) = 05h 47m 27s
   Dec(J2000) = -65d 32' 20"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual for an image trigger, no obvious variation is visible in the immediately-available lightcurve.
The XRT began observing the field at 06:55:49.0 UT, 127.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 86.85414, -65.50357 which is equivalent to:
```
   RA(J2000)  = 05h 47m 24.99s
   Dec(J2000) = -65d 30' 12.9"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 128 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.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (7.76 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.3 (+3.15/-2.74) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 1.57e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 136 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 0.075.
This source lies within the current (Sector 37) field-of-view of TESS camera 4.
Burst Advocate for this burst is S. Laha (sib.laha AT gmail.com). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 19 Apr 21 07:24:54 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1044032,   Seg_Num: 0
GRB_RA:           86.8540d {+05h 47m 24.95s} (J2000),
                  86.8671d {+05h 47m 28.10s} (current),
                  86.8238d {+05h 47m 17.70s} (1950)
GRB_DEC:         -65.5033d {-65d 30' 11.8"} (J2000),
                 -65.4968d {-65d 29' 48.5"} (current),
                 -65.5187d {-65d 31' 07.1"} (1950)
GRB_ERROR:       3.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19323 TJD;   109 DOY;   21/04/19
IMG_START_TIME:  25100.00 SOD {06:58:20.00} UT,   278.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        27.40d {+01h 49m 37s}  +11.28d {+11d 16' 59"}
SUN_DIST:         88.36 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:      109.99d {+07h 19m 58s}  +25.37d {+25d 22' 13"}
MOON_DIST:        92.59 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:      275.19,-31.11 [deg] galactic lon,lat of the burst
ECL_COORDS:       38.16,-88.34 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #29829
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 210419A (Laha, et al., GCN 29828) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on April 19, from 08:33 to 08:57 UT (corresponding to 1.67 to 2.1 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 4x180s exposures in R and I. We do not detect any uncatalogued optical source in the coadded images within the XRT error region (Laha, et al., GCN 29828). Using the USNO-B.1 catalog as reference, we calculate the following upper limits:
R>21.91
I>21.16
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
GCN Circular #29830
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 2647 s of XRT Photon Counting mode data and 4 UVOT images for GRB 210419A, 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 = 86.85096, -65.50250 which is equivalent to:
```
RA (J2000): 05h 47m 24.23s
Dec (J2000): -65d 30' 09.0"
```
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 #29832
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 GRB 210419A ( S. Laha et al., GCN 29828) errorbox 58845 sec after notice time and 58929 sec after trigger time at 2021-04-19 23:15:50 UT, with upper limit up to 18.1 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -14.8 deg.
The galactic latitude b = -31 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=1595763
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   59019 |         MASTER-OAFA |   C |   180 | 17.9 |        
   59305 |         MASTER-OAFA |   C |   180 | 18.1 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #29835
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU) and S. Laha report on behalf of the Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 210419A (Laha et al. GCN Circ. 29828), from 134 s to 64.1 ks after the BAT trigger. The data comprise 143 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 29830).
The late-time light curve (from T0+5.5 ks) can be modelled with a power-law decay with a decay index of alpha=1.0 (+/-0.3).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.71 (+0.11, -0.10). The best-fitting absorption column is 1.4 (+0.4, -0.3) x 10^21 cm^-2, in excess of the Galactic value of 7.8 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.60 (+0.29, -0.27) and a best-fitting absorption column of 1.9 (+0.7, -0.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 2.6 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.9 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 7.8 x 10^20 cm^-2
Excess significance: 2.9 sigma
Photon index:	     2.60 (+0.29, -0.27)
```
If the light curve continues to decay with a power-law decay index of 1.0, the count rate at T+24 hours will be 4.3 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x 10^-13 (2.1 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/01044032.
This circular is an official product of the Swift-XRT team.
GCN Circular #29838
D. M. Palmer (LANL), 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), 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 210419A (trigger #1044032) (Laha et al., GCN Circ. 29828). The BAT ground-calculated position is RA, Dec = 86.912, -65.452 deg which is
```
   RA(J2000)  =  05h 47m 38.9s
   Dec(J2000) = -65d 27' 07.2"
```
with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 61%.
The BAT light curve showed a complex structure with a duration of about ~100 sec. T90 (15-350 keV) is 64.43 +- 11.69 sec (estimated error including systematics).
The time-averaged spectrum from T+21.92 to T+95.01 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.17 +- 0.24. The fluence in the 15-150 keV band is 7.8 +- 1.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+41.82 sec in the 15-150 keV band is 0.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1044032/BA/
GCN Circular #29841
M. H. Siegel (PSU) and S. L. Laha (GSFC/UMBC/CRESST) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210419A 136 s after the BAT trigger (Laha et al., GCN Circ. 29828). No optical afterglow consistent with the XRT position (Osborne et al., GCN Circ 29830) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           136          286          147         >18.1
u_FC               294          544          246         >17.9
white              136         1027          333         >18.1
v                  627         1079           58         >17.5
b                  550          746           39         >17.7
u                  294          721          265         >17.9
w1                 677          871           39         >17.8
m2                 651         1103           58         >18.3
w2                 119         1053           67         >19.3
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.075 in the direction of the burst (Schlegel et al. 1998).

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Jochen Greiner, last update: 20-Apr-2021 [Disclaimer]