Gamma-ray Burst 240419A

(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:     Fri 19 Apr 24 01:48:51 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1222955,   Seg_Num: 0
GRB_RA:           94.568d {+06h 18m 16s} (J2000),
                  94.744d {+06h 18m 59s} (current),
                  94.205d {+06h 16m 49s} (1950)
GRB_DEC:         -45.011d {-45d 00' 40"} (J2000),
                 -45.022d {-45d 01' 20"} (current),
                 -44.990d {-44d 59' 23"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       11826 [cnts]    Image_Peak=284 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   448     E_range: 15-50 keV
BKG_INTEN:       105491 [cnts]
BKG_TIME:        6422.70 SOD {01:47:02.70} UT
BKG_DUR:         40 [sec]
GRB_DATE:        20419 TJD;   110 DOY;   24/04/19
GRB_TIME:        6481.13 SOD {01:48:01.13} UT
GRB_PHI:          65.86 [deg]
GRB_THETA:        11.72 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     10.67 [sigma]
IMAGE_SIGNIF:    6.72 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +1  -3  +0  +0 -12  +0 
SUN_POSTN:        27.44d {+01h 49m 46s}  +11.30d {+11d 17' 49"}
SUN_DIST:         82.59 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.81d {+10h 35m 15s}  +12.61d {+12d 36' 51"}
MOON_DIST:        81.54 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       98.76,-68.31 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 208.93,-7.34 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 19 Apr 24 01:49:57 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.574d {+06h 18m 18s} (J2000)
POINT_DEC:       -45.013d {-45d 00' 47"} (J2000)
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6591.19 SOD {01:49:51.19} UT,   110.1 [sec] since BAT Trigger Time
COUNTS:          37    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        4    Max_iter_allowed= 4
ERROR_CODE:      2
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        Algorithm did not converge; too many iterations.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 19 Apr 24 01:52:17 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1222955,   Seg_Num: 0
GRB_RA:           94.568d {+06h 18m 16s} (J2000),
                  94.744d {+06h 18m 59s} (current),
                  94.205d {+06h 16m 49s} (1950)
GRB_DEC:         -45.011d {-45d 00' 40"} (J2000),
                 -45.022d {-45d 01' 20"} (current),
                 -44.990d {-44d 59' 23"} (1950)
GRB_DATE:        20419 TJD;   110 DOY;   24/04/19
GRB_TIME:        6481.13 SOD {01:48:01.13} UT
TRIGGER_INDEX:   448
GRB_PHI:          65.86 [deg]
GRB_THETA:        11.72 [deg]
DELTA_TIME:      77.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     10.67 [sigma]
IMAGE_SIGNIF:    6.72 [sigma]
LC_URL:          sw01222955000msb.lc
SUN_POSTN:        27.44d {+01h 49m 47s}  +11.30d {+11d 17' 52"}
SUN_DIST:         82.59 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.84d {+10h 35m 21s}  +12.60d {+12d 36' 07"}
MOON_DIST:        81.55 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       98.76,-68.31 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 208.93,-7.34 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 19 Apr 24 01:52:55 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.573d {+06h 18m 18s} (J2000)
POINT_DEC:       -45.013d {-45d 00' 46"} (J2000)
POINT_ROLL:      294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6594.34 SOD {01:49:54.34} UT,   113.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.179
N_STARS:         137
X_OFFSET:        502 [pixels]
Y_OFFSET:        548 [pixels]
X_MAX:           1461 [pixels]
Y_MAX:           1507 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw01222955000msufc0113.fits
SUN_POSTN:        27.44d {+01h 49m 47s}  +11.30d {+11d 17' 53"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.84d {+10h 35m 22s}  +12.60d {+12d 35' 59"}
MOON_DIST:        81.54 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.40 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 19 Apr 24 01:53:09 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.573d {+06h 18m 18s} (J2000)
POINT_DEC:       -45.013d {-45d 00' 46"} (J2000)
POINT_ROLL:      294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6594.34 SOD {01:49:54.34} UT,   113.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.179
N_STARS:         137
X_OFFSET:        502 [pixels]
Y_OFFSET:        548 [pixels]
X_MAX:           1461 [pixels]
Y_MAX:           1507 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw01222955000msufc0113.fits
SUN_POSTN:        27.44d {+01h 49m 47s}  +11.30d {+11d 17' 53"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.85d {+10h 35m 23s}  +12.60d {+12d 35' 56"}
MOON_DIST:        81.54 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.40 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 01:54:22 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.573d {+06h 18m 18s} (J2000)
POINT_DEC:       -45.013d {-45d 00' 46"} (J2000)
ROLL:            294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6594.34 SOD {01:49:54.34} UT,   113.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     735184227
X_OFFSET:        821 [pixels]
Y_OFFSET:        867 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       981
Y_GRB_POS:       1027
BINNING_INDEX:   1
IM_URL:          sw01222955000msuni0147.fits
SUN_POSTN:        27.45d {+01h 49m 47s}  +11.30d {+11d 17' 54"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.85d {+10h 35m 25s}  +12.59d {+12d 35' 40"}
MOON_DIST:        81.55 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.40 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 01:54:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.573d {+06h 18m 18s} (J2000)
POINT_DEC:       -45.013d {-45d 00' 46"} (J2000)
ROLL:            294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6594.34 SOD {01:49:54.34} UT,   113.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     735184227
X_OFFSET:        821 [pixels]
Y_OFFSET:        867 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       981
Y_GRB_POS:       1027
BINNING_INDEX:   1
IM_URL:          sw01222955000msuni0147.fits
SUN_POSTN:        27.45d {+01h 49m 47s}  +11.30d {+11d 17' 54"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.86d {+10h 35m 26s}  +12.59d {+12d 35' 37"}
MOON_DIST:        81.55 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.40 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 01:54:37 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1222955,   Seg_Num: 0
GRB_RA:           94.5342d {+06h 18m 08.20s} (J2000),
                  94.7107d {+06h 18m 50.56s} (current),
                  94.1712d {+06h 16m 41.08s} (1950)
GRB_DEC:         -45.0007d {-45d 00' 02.5"} (J2000),
                 -45.0116d {-45d 00' 41.7"} (current),
                 -44.9796d {-44d 58' 46.4"} (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:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6598.00 SOD {01:49:58.00} UT,   116.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        27.45d {+01h 49m 47s}  +11.30d {+11d 17' 54"}
SUN_DIST:         82.57 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.86d {+10h 35m 26s}  +12.59d {+12d 35' 37"}
MOON_DIST:        81.57 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.72,-24.43 [deg] galactic lon,lat of the burst
ECL_COORDS:       98.70,-68.30 [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 19 Apr 24 02:01:01 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 49"} (J2000)
POINT_ROLL:      294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6752.63 SOD {01:52:32.63} UT,   271.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.549
N_STARS:         144
X_OFFSET:        262 [pixels]
Y_OFFSET:        308 [pixels]
X_MAX:           1701 [pixels]
Y_MAX:           1747 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw01222955000msufc0271.fits
SUN_POSTN:        27.45d {+01h 49m 48s}  +11.30d {+11d 17' 60"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.90d {+10h 35m 37s}  +12.57d {+12d 34' 14"}
MOON_DIST:        81.56 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 19 Apr 24 02:01:14 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 49"} (J2000)
POINT_ROLL:      294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6752.63 SOD {01:52:32.63} UT,   271.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.549
N_STARS:         144
X_OFFSET:        262 [pixels]
Y_OFFSET:        308 [pixels]
X_MAX:           1701 [pixels]
Y_MAX:           1747 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw01222955000msufc0271.fits
SUN_POSTN:        27.45d {+01h 49m 48s}  +11.30d {+11d 17' 60"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.91d {+10h 35m 38s}  +12.57d {+12d 34' 11"}
MOON_DIST:        81.56 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 02:02:10 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 49"} (J2000)
ROLL:            294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6752.63 SOD {01:52:32.63} UT,   271.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     735184385
X_OFFSET:        821 [pixels]
Y_OFFSET:        867 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       981
Y_GRB_POS:       1027
BINNING_INDEX:   1
IM_URL:          sw01222955000msuni0305.fits
SUN_POSTN:        27.45d {+01h 49m 48s}  +11.30d {+11d 18' 01"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.91d {+10h 35m 39s}  +12.57d {+12d 33' 59"}
MOON_DIST:        81.56 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 02:02:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 49"} (J2000)
ROLL:            294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6752.63 SOD {01:52:32.63} UT,   271.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     735184385
X_OFFSET:        821 [pixels]
Y_OFFSET:        867 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       981
Y_GRB_POS:       1027
BINNING_INDEX:   1
IM_URL:          sw01222955000msuni0305.fits
SUN_POSTN:        27.45d {+01h 49m 48s}  +11.30d {+11d 18' 01"}
SUN_DIST:         82.60 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.91d {+10h 35m 40s}  +12.57d {+12d 33' 57"}
MOON_DIST:        81.56 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #36169
M. H. Siegel (PSU), S. Dichiara (PSU), R. Gupta (NASA/GSFC), J. A. Kennea (PSU), S. Laha (GSFC/UMBC), D. M. Palmer (LANL) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 01:48:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240419A (trigger=1222955). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 94.568, -45.011 which is
```
   RA(J2000) = 06h 18m 16s
   Dec(J2000) = -45d 00' 40"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 4 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 01:49:51.1 UT, 110.1 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 94.53468, -45.00073 which is equivalent to:
```
   RA(J2000)  = 06h 18m 08.32s
   Dec(J2000) = -45d 00' 02.6"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 92 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 consistent with the Galactic value of 6.63 x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 113 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 0.069.
Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 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:     Fri 19 Apr 24 02:03:24 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1222955,   Seg_Num: 0
GRB_RA:           94.5334d {+06h 18m 08.01s} (J2000),
                  94.7099d {+06h 18m 50.36s} (current),
                  94.1704d {+06h 16m 40.89s} (1950)
GRB_DEC:         -45.0001d {-45d 00' 00.3"} (J2000),
                 -45.0110d {-45d 00' 39.5"} (current),
                 -44.9790d {-44d 58' 44.3"} (1950)
GRB_ERROR:       1.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  6598.00 SOD {01:49:58.00} UT,   116.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        27.45d {+01h 49m 48s}  +11.30d {+11d 18' 02"}
SUN_DIST:         82.56 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      158.92d {+10h 35m 41s}  +12.56d {+12d 33' 43"}
MOON_DIST:        81.58 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.72,-24.43 [deg] galactic lon,lat of the burst
ECL_COORDS:       98.69,-68.30 [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 19 Apr 24 02:21:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 48"} (J2000)
POINT_ROLL:      294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  7356.12 SOD {02:02:36.12} UT,   875.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.546
N_STARS:         190
X_OFFSET:        262 [pixels]
Y_OFFSET:        308 [pixels]
X_MAX:           1701 [pixels]
Y_MAX:           1747 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01222955000msufc0874.fits
SUN_POSTN:        27.46d {+01h 49m 51s}  +11.30d {+11d 18' 17"}
SUN_DIST:         82.59 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      159.06d {+10h 36m 13s}  +12.50d {+12d 29' 57"}
MOON_DIST:        81.60 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 19 Apr 24 02:21:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 48"} (J2000)
POINT_ROLL:      294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  7356.12 SOD {02:02:36.12} UT,   875.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.546
N_STARS:         190
X_OFFSET:        262 [pixels]
Y_OFFSET:        308 [pixels]
X_MAX:           1701 [pixels]
Y_MAX:           1747 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01222955000msufc0874.fits
SUN_POSTN:        27.46d {+01h 49m 51s}  +11.30d {+11d 18' 17"}
SUN_DIST:         82.59 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      159.06d {+10h 36m 14s}  +12.50d {+12d 29' 53"}
MOON_DIST:        81.60 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 02:22:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 48"} (J2000)
ROLL:            294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  7356.12 SOD {02:02:36.12} UT,   875.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     735184989
X_OFFSET:        821 [pixels]
Y_OFFSET:        867 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       981
Y_GRB_POS:       1027
BINNING_INDEX:   1
IM_URL:          sw01222955000msuni0908.fits
SUN_POSTN:        27.46d {+01h 49m 51s}  +11.30d {+11d 18' 18"}
SUN_DIST:         82.59 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      159.07d {+10h 36m 16s}  +12.49d {+12d 29' 39"}
MOON_DIST:        81.60 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 19 Apr 24 02:22:14 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1222955,   Seg_Num: 0
POINT_RA:         94.572d {+06h 18m 17s} (J2000)
POINT_DEC:       -45.014d {-45d 00' 48"} (J2000)
ROLL:            294.317d
IMG_START_DATE:  20419 TJD;   110 DOY;   24/04/19
IMG_START_TIME:  7356.12 SOD {02:02:36.12} UT,   875.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     735184989
X_OFFSET:        821 [pixels]
Y_OFFSET:        867 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       981
Y_GRB_POS:       1027
BINNING_INDEX:   1
IM_URL:          sw01222955000msuni0908.fits
SUN_POSTN:        27.46d {+01h 49m 51s}  +11.30d {+11d 18' 18"}
SUN_DIST:         82.59 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:      159.07d {+10h 36m 16s}  +12.49d {+12d 29' 41"}
MOON_DIST:        81.60 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:      252.74,-24.41 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       98.77,-68.31 [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 #36170
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 240419A, we find an enhanced XRT position of the afterglow: RA, Dec: 94.53358, -44.99999 which is equivalent to:
```
   RA (J2000)  = 06 18 08.06
   Dec (J2000) = -44 59 60.0
```
with an uncertainty of 1.9 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/1222955.
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 #36174
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 977 s of XRT Photon Counting mode data and 1 UVOT images for GRB 240419A, 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 = 94.53406, -44.99952 which is equivalent to:
```
RA (J2000): 06h 18m 8.17s
Dec (J2000): -44d 59' 58.3"
```
with an uncertainty of 2.2 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 #36175
B. Schneider (MIT), N. Gaspari (Radboud Univ.), N. R. Tanvir (Univ. Leicester), S. Covino (INAF/Brera), D. B. Malesani (DAWN/NBI and Radboud Univ.), L. Izzo (INAF/Napoli and DARK/NBI), A. Saccardi (GEPI/Obs. Paris), report on behalf of the Stargate collaboration.
We observed the field of GRB 240419A (Siegel et al., GCN 36169) using the ESO VLT UT1 equipped with the FORS2 camera. Observations were commenced automatically in rapid-response mode (RRM). The first image was acquired on April 19.0895 UT, that is, 20.9 min after the GRB, and consisted of a 20 s image in the R filter. At a relatively high airmass of 2.1, the delivered PSF was 1.4".
A source, not present in archival images, is detected within the UVOT-enhanced XRT error circle (Goad et al., GCN 36174), at coordinates (J2000):
```
RA = 06:18:08.17
Dec = -44:59:57.3
```
Using FORS2 zeropoints, we measure for the source a magnitude R = 19.88 +- 0.05 (Vega), in excellent agreement with photometry calibrated against nearby stars from the SkyMapper catalog.
Further observations have been secured and will be reported at a later time. We acknowledge excellent support from the ESO observing staff in Paranal.
GCN Circular #36176
B. Schneider (MIT), L. Izzo (INAF-Napoli & DARK/NBI), A. Saccardi (GEPI/Obs. de Paris), D. B. Malesani (DAWN/NBI and Radboud Univ.), J. T. Palmerio (GEPI, Obs. de Paris), A. de Ugarte Postigo (CNRS, OCA, LAM), V. D'Elia (ASI/SSDC & INAF-OAR), N. Gaspari (Radboud Univ.), P. Schady (Univ. of Bath), S. Covino (INAF/Brera), N. R. Tanvir (Univ. Leicester), A. J. Levan (Radboud Univ.), B. P. Gompertz (Birmingham), report on behalf of the Stargate collaboration:
We observed the optical afterglow of GRB 240419A (Siegel et al., GCN 36169; Schneider et al., GCN 36175) using the ESO VLT UT2 (Kueyen) equipped with the UVES high-resolution spectrograph. Observations were automatically performed via the rapid-response mode (RRM) system. The observations consisted of a series of spectra taken on April 19 with the first one starting at 02:15:42 UT (27.7 min after the GRB). The spectra cover a wavelength range from 3700 to 9300 AA and were obtained at a relatively high airmass of 2.4.
In the spectrum of 700 s, we only detect a continuum in the upper chip of the red arm (7770 to 9300 AA). From the detection of multiple absorption features, which we interpret as being due to SII, OI, Si II, Si II*, CII, CII*, Si IV, we infer a common redshift of z = 5.178. We conclude this is the redshift of the burst. This is consistent with the absence of flux in the blue dichroic, which covers the wavelength range from 3300 to 5000 AA, and which is entirely blue-ward of the Lyman break at z = 5.178. We also note the presence of additional absorption features likely due multiple intervening systems.
We acknowledge expert support from the ESO staff in Paranal, in particular Jonathan Smoker and Diego Parraguez.
GCN Circular #36182
A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU) and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 7.8 ks of XRT data for GRB 240419A, from 117 s to 33.6 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode.
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=5.3 (+2.7, -0.8). At T+249 s the decay flattens to an alpha of -0.2 (+0.7, -0.6) before breaking again at T+1406 s to a final decay with index alpha=1.20 (+0.32, -0.25).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.30 (+0.30, -0.27). The best-fitting absorption column is 2.4 (+1.1, -0.9) x 10^21 cm^-2, in excess of the Galactic value of 6.6 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 (5.1 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.4 (+1.1, -0.9) x 10^21 cm^-2
Galactic foreground: 6.6 x 10^20 cm^-2
Excess significance: 3.1 sigma
Photon index:	     2.30 (+0.30, -0.27)
```
If the light curve continues to decay with a power-law decay index of 1.20, the count rate at T+24 hours will be 2.8 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.7 x 10^-14 (1.4 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/01222955.
This circular is an official product of the Swift-XRT team.
GCN Circular #36183
M. Ferro, Y.-D. Hu, P. D=E2=80=99Avanzo, R. Brivio, S. Covino, D. Fugazza (INAF-OAB) on behalf of the REM team, report:
We observed for the field of GRB 240419A (Siegel et al., GCN 36169) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, J, H, K bands, starting on 2024 April 19 at 01:49:38 UT (i.e. 1.6 minutes after the event), and lasting for about 3 hours. From preliminary photometry we detect the NIR afterglow at a position consistent with the optical afterglow position (Schneider et al., GCN 36175), at the following AB magnitude in the H band:
H = 15.7 +- 0.1 (calibrated against 2MASS catalogue) at a mid time of t-t0 ~ 4 minutes after the GRB trigger.
The afterglow is not detected in our optical observations, at the following AB magnitude limit in the r band:
r > 19.2 (calibrated against SkyMapper catalogue) at a mid time of t-t0 ~ 6.3 minutes after the GRB trigger.
GCN Circular #36185
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (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. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich (Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 240419A ( M. H. Siegel et al., GCN 36169) errorbox 54337 sec after notice time and 54397 sec after trigger time at 2024-04-19 16:54:39 UT, with upper limit up to 17.8 mag. Observations started at twilight. The observations began at zenith distance = 25 deg. The sun altitude is -9.6 deg.
The galactic latitude b = -24 deg., longitude l = 253 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2427118
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   54488 |         MASTER-SAAO |   C |   180 | 17.8 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #36193
S. P. R. Shilling (Lancaster U.), S. R. Oates (Lancaster U.), A. A. Breeveld (UCL-MSSL), M. De Pasquale (Univ. of Messina) and M. H. Siegel (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240419A 113 s after the BAT trigger (Siegel et al., GCN Circ. 36169). No optical afterglow consistent with the enhanced XRT position (Goad et al., GCN Circ. 36174) 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) exposures and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           113          263          147         >20.7
u_FC               271          521          246         >20.0
white              113         1025          334         >21.3
v                  602         1075           58         >18.6
b                  527          721           39         >19.3
u                  271          869          285         >20.1
w1                 652          845           39         >18.2
m2                 627         1099           58         >18.3
w2                 578         1050           58         >18.6
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.070 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #36200
Megan Dubay, Donovan Schlekat, Dylan Dutton, Daniel Reichart, Joshua Haisli= p, and Vladimir Kouprianov report on behalf of the Skynet Robotic Telescope= Network at the University of North Carolina at Chapel Hill.
We observed the field of GRB 240419A with one of Skynet=E2=80=99s 16=E2=80= =9D-diameter PROMPT telescopes at CTIO. The first detection occurred in the= I band approximately 1 hour after the trigger reported by Swift (Siegel et= al., GCN 36169).
We detect the afterglow with coordinates consistent with those reported by = VLT (B. Schneider et al., GCN 36175) and REM (Ferro et al., GCN 36183).
The coordinates are:
```
R.A. (J2000):  06:18:08.18
Dec. (J2000): -44:59:57.60
```
We report the photometry below.
```
ExpLen | Filter | Mag   | Mag Error  | MJD (Center)
------------------------------------------------
45x8   | I      | 19.06 | 0.199      | 60419.119
60x8   | R      | ----- | -----      | 60419.119
```
We report non-detection in the R-band from the reported time with an upper magnitude limit of 20.39.
We note that the large R-I color is consistent with the presence of the Lyman-alpha forest in the R band, given its large redshift (Schneider et al., GCN 36176, Lamb & Reichart 2000).
Our images have been calibrated using stars from the APASS catalog.
GCN Circular #36250
S. Chastain (UNM), G. E. Anderson (Curtin University), J. K. Leung (U. Toronto/HUJI), L. Rhodes (U. Oxford), S. D. Ryder (Macquarie), A. Gulati (U. Sydney), A. J. van der Horst (GWU), on behalf of the PanRadio GRB collaboration
The Australia Telescope Compact Array (ATCA) performed rapid follow-up observations of GRB 240419A (Siegel et al., GCN 36169) at 5.5, 9, and 18 GHz as part of the Long-term ATCA "PanRadio GRB" follow-up programme C3542 (PI. Anderson). ATCA began observing at 2024-04-19 04:00 UT (2.2 hours post-burst) up until 12:30 UT. In our preliminary analysis, we have a marginal detect of 63 +/- 18 microJy/beam at 18 GHz that is coincident with the enhanced XRT position (Goad et al., GCN 36174). We obtain 3 sigma upper limits of 39 and 42 microJy/beam at 5.5 and 9.0, respectively. Further observations are planned.
We thank the CSIRO Space and Astronomy staff for supporting these observations. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is funded by the Australian Government for operation as a National Facility managed by CSIRO.
GCN Circular #36255
T. Parsotan (GSFC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. H. Siegel (PSU) (i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240419A (trigger #1222955) (Siegel, et al., GCN Circ. 36169). The BAT ground-calculated position is RA, Dec = 94.505, -44.964 deg which is
```
   RA(J2000)  =  06h 18m 01.3s
   Dec(J2000) = -44d 57' 50.2"
```
with an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 89%.
The mask-weighted light curve shows two dim pulses at T0-7 s and T0+0 s, respectively. The T90 (15-350 keV) is 3.00 +- 1.41 sec (estimated error including systematics).
The time-averaged spectrum from T-0.43 to T+2.57 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.71 +- 0.38. The fluence in the 15-150 keV band is 8.4 +- 2.1 x 10^-08 erg/cm2. The 1-sec peak photon flux measured from T+0.57 sec in the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1222955

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Jochen Greiner, last update: 23-Apr-2024 [Disclaimer]