Gamma-ray Burst 220430A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:57:50 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1104692,   Seg_Num: 0
GRB_RA:           97.611d {+06h 30m 27s} (J2000),
                  97.917d {+06h 31m 40s} (current),
                  96.924d {+06h 27m 42s} (1950)
GRB_DEC:          +9.510d {+09d 30' 36"} (J2000),
                  +9.493d {+09d 29' 36"} (current),
                  +9.545d {+09d 32' 43"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2870 [cnts]    Image_Peak=154 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   155     E_range: 50-350 keV
BKG_INTEN:       14334 [cnts]
BKG_TIME:        49978.94 SOD {13:52:58.94} UT
BKG_DUR:         8 [sec]
GRB_DATE:        19699 TJD;   120 DOY;   22/04/30
GRB_TIME:        49995.96 SOD {13:53:15.96} UT
GRB_PHI:         -55.21 [deg]
GRB_THETA:         1.40 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     22.75 [sigma]
IMAGE_SIGNIF:    7.24 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +3  -3  +0  +1 -51  +0 
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 44"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.05d {+02h 20m 11s}  +12.61d {+12d 36' 21"}
MOON_DIST:        61.65 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       97.73,-13.73 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integratio
n interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
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 = 13.59,10.18 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:58:26 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1104692,   Seg_Num: 0
GRB_RA:           97.6132d {+06h 30m 27.16s} (J2000),
                  97.9200d {+06h 31m 40.79s} (current),
                  96.9261d {+06h 27m 42.27s} (1950)
GRB_DEC:          +9.5475d {+09d 32' 50.9"} (J2000),
                  +9.5307d {+09d 31' 50.5"} (current),
                  +9.5827d {+09d 34' 57.8"} (1950)
GRB_ERROR:       5.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       4.31e-08 [erg/cm2/sec]
GRB_SIGNIF:      7.28 [sigma]
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50047.73 SOD {13:54:07.73} UT,   51.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.69 237.16 261.79 243.70
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 45"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.05d {+02h 20m 12s}  +12.61d {+12d 36' 29"}
MOON_DIST:        61.64 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.05, -0.26 [deg] galactic lon,lat of the burst
ECL_COORDS:       97.73,-13.69 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.24 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:58:36 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
GRB_RA:           97.6132d {+06h 30m 27.1s} (J2000),
                  97.9200d {+06h 31m 40.7s} (current),
                  96.9261d {+06h 27m 42.2s} (1950)
GRB_DEC:          +9.5475d {+09d 32' 50.9"} (J2000),
                  +9.5307d {+09d 31' 50.5"} (current),
                  +9.5827d {+09d 34' 57.8"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       53 [cnts]
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50047.73 SOD {13:54:07.73} UT,   51.8 [sec] since BAT Trigger Time
CENTROID_X:      302.68,  raw= 303  [pixels]
CENTROID_Y:      249.79,  raw= 250  [pixels]
ROLL:            281.72 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -113.86
GRB_POS_XRT_Z:   -11.10
IMAGE_URL:       sw01104692000msxps_rw.img
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 45"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.05d {+02h 20m 13s}  +12.61d {+12d 36' 31"}
MOON_DIST:        61.64 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.05, -0.26 [deg] galactic lon,lat of the burst
ECL_COORDS:       97.73,-13.69 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:58:41 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
GRB_RA:           97.6132d {+06h 30m 27.1s} (J2000),
                  97.9200d {+06h 31m 40.7s} (current),
                  96.9261d {+06h 27m 42.2s} (1950)
GRB_DEC:          +9.5475d {+09d 32' 50.9"} (J2000),
                  +9.5307d {+09d 31' 50.5"} (current),
                  +9.5827d {+09d 34' 57.8"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       53 [cnts]
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50047.73 SOD {13:54:07.73} UT,   51.8 [sec] since BAT Trigger Time
CENTROID_X:      302.68,  raw= 303  [pixels]
CENTROID_Y:      249.79,  raw= 250  [pixels]
ROLL:            281.72 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -113.86
GRB_POS_XRT_Z:   -11.10
IMAGE_URL:       sw01104692000msxps_rw.img
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 45"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.05d {+02h 20m 13s}  +12.61d {+12d 36' 32"}
MOON_DIST:        61.64 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.05, -0.26 [deg] galactic lon,lat of the burst
ECL_COORDS:       97.73,-13.69 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:58:54 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1104692,   Seg_Num: 0
GRB_RA:           97.611d {+06h 30m 27s} (J2000),
                  97.917d {+06h 31m 40s} (current),
                  96.924d {+06h 27m 42s} (1950)
GRB_DEC:          +9.510d {+09d 30' 36"} (J2000),
                  +9.493d {+09d 29' 36"} (current),
                  +9.545d {+09d 32' 43"} (1950)
GRB_DATE:        19699 TJD;   120 DOY;   22/04/30
GRB_TIME:        49995.96 SOD {13:53:15.96} UT
TRIGGER_INDEX:   155
GRB_PHI:         -55.21 [deg]
GRB_THETA:         1.40 [deg]
DELTA_TIME:      57.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     22.75 [sigma]
IMAGE_SIGNIF:    7.24 [sigma]
LC_URL:          sw01104692000msb.lc
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 45"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.05d {+02h 20m 13s}  +12.61d {+12d 36' 35"}
MOON_DIST:        61.64 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       97.73,-13.73 [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 = 13.59,10.18 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:59:18 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 58"} (J2000)
POINT_ROLL:      281.716d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50056.16 SOD {13:54:16.16} UT,   60.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.684
N_STARS:         170
X_OFFSET:        448 [pixels]
Y_OFFSET:        528 [pixels]
X_MAX:           1407 [pixels]
Y_MAX:           1487 [pixels]
DET_THRESH:      18
PHOTO_THRESH:    10
SL_URL:          sw01104692000msufc0060.fits
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 46"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.06d {+02h 20m 14s}  +12.61d {+12d 36' 40"}
MOON_DIST:        61.63 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 13:59:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 58"} (J2000)
POINT_ROLL:      281.716d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50056.16 SOD {13:54:16.16} UT,   60.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.684
N_STARS:         170
X_OFFSET:        448 [pixels]
Y_OFFSET:        528 [pixels]
X_MAX:           1407 [pixels]
Y_MAX:           1487 [pixels]
DET_THRESH:      18
PHOTO_THRESH:    10
SL_URL:          sw01104692000msufc0060.fits
SUN_POSTN:        37.80d {+02h 31m 12s}  +14.88d {+14d 52' 46"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.06d {+02h 20m 14s}  +12.61d {+12d 36' 44"}
MOON_DIST:        61.63 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:02:20 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 58"} (J2000)
ROLL:            281.716d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50056.16 SOD {13:54:16.16} UT,   60.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     673019685
X_OFFSET:        926 [pixels]
Y_OFFSET:        1064 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1086
Y_GRB_POS:       1224
BINNING_INDEX:   1
IM_URL:          sw01104692000msuni0090.fits
SUN_POSTN:        37.80d {+02h 31m 13s}  +14.88d {+14d 52' 48"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.08d {+02h 20m 20s}  +12.62d {+12d 37' 19"}
MOON_DIST:        61.61 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:02:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 58"} (J2000)
ROLL:            281.716d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50056.16 SOD {13:54:16.16} UT,   60.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     673019685
X_OFFSET:        926 [pixels]
Y_OFFSET:        1064 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1086
Y_GRB_POS:       1224
BINNING_INDEX:   1
IM_URL:          sw01104692000msuni0090.fits
SUN_POSTN:        37.80d {+02h 31m 13s}  +14.88d {+14d 52' 48"}
SUN_DIST:         58.85 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.08d {+02h 20m 20s}  +12.62d {+12d 37' 22"}
MOON_DIST:        61.61 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:06:56 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
POINT_ROLL:      281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50268.39 SOD {13:57:48.39} UT,   272.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.435
N_STARS:         93
X_OFFSET:        606 [pixels]
Y_OFFSET:        744 [pixels]
X_MAX:           1565 [pixels]
Y_MAX:           1703 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01104692000msufc0272.fits
SUN_POSTN:        37.81d {+02h 31m 13s}  +14.88d {+14d 52' 51"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.12d {+02h 20m 29s}  +12.64d {+12d 38' 18"}
MOON_DIST:        61.57 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 14:07:09 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
POINT_ROLL:      281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50268.39 SOD {13:57:48.39} UT,   272.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.435
N_STARS:         93
X_OFFSET:        606 [pixels]
Y_OFFSET:        744 [pixels]
X_MAX:           1565 [pixels]
Y_MAX:           1703 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01104692000msufc0272.fits
SUN_POSTN:        37.81d {+02h 31m 13s}  +14.88d {+14d 52' 52"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.12d {+02h 20m 29s}  +12.64d {+12d 38' 21"}
MOON_DIST:        61.57 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:13:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
POINT_ROLL:      281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50871.22 SOD {14:07:51.22} UT,   875.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.975
N_STARS:         190
X_OFFSET:        366 [pixels]
Y_OFFSET:        504 [pixels]
X_MAX:           1805 [pixels]
Y_MAX:           1943 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw01104692000msufc0875.fits
SUN_POSTN:        37.81d {+02h 31m 14s}  +14.88d {+14d 52' 56"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.17d {+02h 20m 42s}  +12.66d {+12d 39' 43"}
MOON_DIST:        61.52 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 14:15:05 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
ROLL:            281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50871.22 SOD {14:07:51.22} UT,   875.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     673020500
X_OFFSET:        925 [pixels]
Y_OFFSET:        1063 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1085
Y_GRB_POS:       1223
BINNING_INDEX:   1
IM_URL:          sw01104692000msuni0905.fits
SUN_POSTN:        37.81d {+02h 31m 15s}  +14.88d {+14d 52' 58"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.19d {+02h 20m 45s}  +12.67d {+12d 40' 02"}
MOON_DIST:        61.50 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:13:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
POINT_ROLL:      281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50871.22 SOD {14:07:51.22} UT,   875.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.975
N_STARS:         190
X_OFFSET:        366 [pixels]
Y_OFFSET:        504 [pixels]
X_MAX:           1805 [pixels]
Y_MAX:           1943 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw01104692000msufc0875.fits
SUN_POSTN:        37.81d {+02h 31m 14s}  +14.88d {+14d 52' 57"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.18d {+02h 20m 42s}  +12.66d {+12d 39' 47"}
MOON_DIST:        61.51 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN Circular #31972
E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), C. Gronwall (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU), A. Y. Lien (U Tampa), 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 13:53:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 220430A (trigger=1104692). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 97.611, +9.510 which is
```
   RA(J2000) = 06h 30m 27s
   Dec(J2000) = +09d 30' 36"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve appears to show a double-peaked structure with the second peak larger, and a total duration of about 70 sec. The peak count rate was ~35000 counts/sec (15-350 keV), at ~38 sec after the trigger.
However, near the time of the GRB the Sun also produced an X-class solar flare which may be the cause of some or all of the apparent lightcurve activity. The GRB emission will be independently determined once the mask-tagged BAT data has been received.
The XRT began observing the field at 13:54:07.7 UT, 51.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source with an enhanced position: RA, Dec 97.61267, 9.54730 which is equivalent to:
```
   RA(J2000)  = 06h 30m 27.04s
   Dec(J2000) = +09d 32' 50.3"
```
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 134 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 (6.47 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 1.1 (+0.75/-0.59) x 10^22 cm^-2 (90% confidence).
The initial flux in the 0.1 s image was 4.31e-08 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 60 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 large, but uncertain, extinction expected.
Although this looks like a GRB both in terms of its lightcurve and the presence of strong flux above 100 keV, its location near the Galactic plane (lon=202.05, lat=-0.26) raises the possibility of it being a Galactic transient. In addition, as noted above, the apparent lightcurve may be due to solar activity. If further analysis shows that it is a Galactic transient, we will use the name Swift J0630.4+0932.
Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 Apr 22 14:08:10 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
ROLL:            281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50268.39 SOD {13:57:48.39} UT,   272.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     673019897
X_OFFSET:        926 [pixels]
Y_OFFSET:        1064 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1086
Y_GRB_POS:       1224
BINNING_INDEX:   1
IM_URL:          sw01104692000msuni0302.fits
SUN_POSTN:        37.81d {+02h 31m 14s}  +14.88d {+14d 52' 52"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.13d {+02h 20m 31s}  +12.64d {+12d 38' 34"}
MOON_DIST:        61.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:08:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
ROLL:            281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50268.39 SOD {13:57:48.39} UT,   272.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     673019897
X_OFFSET:        926 [pixels]
Y_OFFSET:        1064 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1086
Y_GRB_POS:       1224
BINNING_INDEX:   1
IM_URL:          sw01104692000msuni0302.fits
SUN_POSTN:        37.81d {+02h 31m 14s}  +14.88d {+14d 52' 52"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.13d {+02h 20m 31s}  +12.64d {+12d 38' 35"}
MOON_DIST:        61.56 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:15:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1104692,   Seg_Num: 0
POINT_RA:         97.610d {+06h 30m 26s} (J2000)
POINT_DEC:        +9.516d {+09d 30' 57"} (J2000)
ROLL:            281.717d
IMG_START_DATE:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50871.22 SOD {14:07:51.22} UT,   875.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     673020500
X_OFFSET:        925 [pixels]
Y_OFFSET:        1063 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1085
Y_GRB_POS:       1223
BINNING_INDEX:   1
IM_URL:          sw01104692000msuni0905.fits
SUN_POSTN:        37.81d {+02h 31m 15s}  +14.88d {+14d 52' 58"}
SUN_DIST:         58.84 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.19d {+02h 20m 45s}  +12.67d {+12d 40' 05"}
MOON_DIST:        61.50 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.08, -0.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       97.73,-13.72 [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:     Sat 30 Apr 22 14:14:39 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1104692,   Seg_Num: 0
GRB_RA:           97.6093d {+06h 30m 26.23s} (J2000),
                  97.9161d {+06h 31m 39.86s} (current),
                  96.9222d {+06h 27m 41.33s} (1950)
GRB_DEC:          +9.5495d {+09d 32' 58.2"} (J2000),
                  +9.5327d {+09d 31' 57.7"} (current),
                  +9.5847d {+09d 35' 04.9"} (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:  19699 TJD;   120 DOY;   22/04/30
IMG_START_TIME:  50593.00 SOD {14:03:13.00} UT,   597.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        37.81d {+02h 31m 15s}  +14.88d {+14d 52' 57"}
SUN_DIST:         58.83 [deg]   Sun_angle= -4.0 [hr] (East of Sun)
MOON_POSTN:       35.18d {+02h 20m 44s}  +12.67d {+12d 39' 56"}
MOON_DIST:        61.50 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      202.05, -0.27 [deg] galactic lon,lat of the burst
ECL_COORDS:       97.72,-13.69 [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 Circular #31973
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 1120 s of XRT Photon Counting mode data and 3 UVOT images for GRB 220430A, 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 = 97.61218, +9.54754 which is equivalent to: RA (J2000): 06h 30m 26.92s Dec (J2000): +09d 32' 51.1" 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 #31974
P.J. Groot (Radboud/UCT/SAAO), S.de Wet (UCT), D.B. Malesani (Radboud, DAWN/NBI), A.J. Levan (Radboud), P.M. Vreeswijk (Radboud), report on behalf of the MeerLICHT consortium:
GRB220430A (Ambrosi et al., GCN 31972) triggered automatic observations with the 0.6m wide-field MeerLICHT telescope, located at Sutherland, South Africa. Observations started at 2022-04-30, 17:10:19 UT in a series of 60s integrations in an alternating sequence of the u,g,q,r,i,z bands. Observations were stopped after 2022-04-30, 17:27:48 UT due to the visibility of the source location.
A preliminary analysis of the u, q and i-band images shows no new optical transient in these bands within the Swift-BAT error circle, including the position of the new X-ray source detected in the Swift-XRT observations.
Five-sigma limiting magnitudes for an optical transient located at the Swift-XRT position are:
```
u > 19.0 at 17:11:46 UT, 
q > 20.4 at 17:13:14 UT, 
i > 18.6 at 17:20:32 UT. 
```
Further analysis is ongoing
MeerLICHT is built and run by a consortium consisting of Radboud University, the University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.
GCN Circular #31975
A. Ursi (INAF/IAPS), F. Longo (Univ. Trieste and INFN Trieste), F. Verrecchia, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, E. Menegoni, L. Foffano, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, A. Di Piano, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team:
The AGILE satellite detected the GRB 220430A at T0 = 2022-04-30 13:53:45 (UTC), reported by Swift (GCNs #31972 and #31973).
The burst is clearly visible in the AGILE scientific ratemeters of the SuperAGILE detector (SA; 20-60 keV) and in all the five panels of the AntiCoincidence system (AC Top, 50-200 keV; AC Lat, 80-200 keV). The event lasted about 25 s and it released a total number of 2685 counts in the SA detector (above a background rate of 100 Hz), 25765 counts in the MCAL detector (above a background rate of 1070 Hz), and 67565 counts in the AC detector (above a background rate of 2710 Hz). The AGILE ratemeter light curves can be found at http://www.agilescienceapp.it/notices/GRB220430A_AGILE_RM.png .
As pointed out in GCN #31972, we notice that this event took place at the end of an intense X-class solar flare, clearly detected by all the AGILE scientific ratemeters. A more extended light curve can be found at http://www.agilescienceapp.it/notices/GRB220430A_AGILE_RM_all.png .
Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN Circular #31976
N. Pankov (HSE), S. Belkin (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), R. Ya. Inasaridze (AbAO) report on behalf of GRB IKI FuN:
We observed the field of Swift GRB 220430A (Ambrosi et al., GCN 31972) also detected by AGILE (Ursi et al., GCN 31975) with AZT-33 telescope of Mondy observatory starting on April, 30 (UT) 14:20:53 and AS-32 telescope of Abastumani observatory starting on April, 30 (UT) 16:59:12. We do not detect any sources in the enhanced position of Swift-XRT (Osborne et al., GCN 31973) consistent with the observations of Swit/UVOT (Ambrosi et al., GCN 31972) and MeerLICHT (Groot et al., GCN 31974). Preliminary photometry of the combined images is following
```
  Date,      UT start, t-T0,   Exp.,  Filter, OT,    Err,  UL(3 sigma)
                     (mid, days)

2022-04-30  14:20:53 0.01953    1*60   R      n/d    n/d    19.5
2022-04-30  14:20:53 0.02613   20*60   R      n/d    n/d    20.5
2022-04-30  16:59:12 0.14962   59*60   R      n/d    n/d    21.0
```
The photometry is based on nearby USNO-B1.0 stars, R2 magnitude
```
USNO-B1.0_id R2
0995-0113632 16.50
0995-0113723 15.94
```
GCN Circular #31977
D. Dornic (CPPM), A. Klotz (CNRS-OMP-IRAP), A. Sabahaddin (ShaO), T. Midavaine (KNC), V. Rupchandani (AUS), P. A. Duverne (IJCLAB), Y. Rajabov (UBAI), X. Song (BJP), X. F. Wang (THU/BJP), J. Zhu (BJP), L. Wang,� X. Zeng, A. Iskandar (XAO), P. Thierry (AGORA), A. Kaeouach (Tanger), Z. Benkhaldoun (OUCA), S. Antier, A. de Ugarte Postigo (CNRS-OCA-ARTEMIS) report on behalf of GRANDMA collaboration:
The GRANDMA telescope network responded to the alert of GRB 220430A (Ambrosi et al. GCN 31972, Osborne et al., GCN 31973, Groot et al., GCN 31974, Ursi� et al., GCN 31975, Pozanenko et al. GCN 31976). The first observations started 34 min after the SWIFT BAT trigger time.
We did not detect any optical transient within the XRT error box during the first 2.9 hours. We report our 3-sigma upper limits. Magnitudes are given in the AB system.
```
T-T0 (hr)| MJD������ | Obser.�� |Exposure| Filter| Upp.Lim. (AB)
0.56111� |59699.60204| SNOVA ���� | 4x300s | Clear | 19.0
2.59194� |59699.68666| Makes-T60| 10x120s| Clear | 19.5
6.24347� |59699.83880| HAO����� | 20x120s| L���� | 20.6
6.33472� |59699.84260| MOSS���� | 30x60s | Clear | 21.0
```
The images have been calibrated with SDSS DR7. T-T0 is the started date.
GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).
GCN Circular #31978
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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 (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),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University)
MASTER-OAGH robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) was pointed to the Swift GRB 220430A ( E. Ambrosi et al., GCN 31972) errorbox 46599 sec after notice time and 46878 sec after trigger time at 2022-05-01 02:54:34 UT, with upper limit up to 15.0 mag. Observations started at twilight. The observations began at zenith distance = 56 deg. The sun altitude is -12.3 deg.
The galactic latitude b = 0 deg., longitude l = 202 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1959132
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   46968 |         MASTER-OAGH |   C |   180 | 15.0 |        
   46968 |         MASTER-OAGH |   C |   180 | 14.9 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #31979
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), K.L. Page (U. Leicester) and E. Ambrosi report on behalf of the Swift-XRT team:
We have analysed 7.6 ks of XRT data for GRB 220430A (Ambrosi et al. GCN Circ. 31972), from 39 s to 39.2 ks after the BAT trigger. The data comprise 539 s in Windowed Timing (WT) mode (the first 11 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 31973).
The late-time light curve (from T0+4.2 ks) can be modelled with a power-law decay with a decay index of alpha=1.35 (+/-0.09).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.65 (+/-0.05). The best-fitting absorption column is 1.05 (+0.07, -0.06) x 10^22 cm^-2, in excess of the Galactic value of 6.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.85 (+0.17, -0.16) and a best-fitting absorption column of 1.03 (+0.19, -0.17) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.3 x 10^-11 (8.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.03 (+0.19, -0.17) x 10^22 cm^-2
Galactic foreground: 6.5 x 10^21 cm^-2
Excess significance: 3.8 sigma
Photon index:	     1.85 (+0.17, -0.16)
```
If the light curve continues to decay with a power-law decay index of 1.35, the count rate at T+24 hours will be 0.015 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.0 x 10^-13 (1.4 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01104692.
This circular is an official product of the Swift-XRT team.
GCN Circular #31980
Y.-D. Hu, T.-R. Sun, M. D. Caballero-Garcia, R. Sanchez-Ramirez, I. Perez-Garcia and A. J. Castro-Tirado (IAA-CSIC), R. Minguez and I. Vico (CAHA) on behalf of a larger collaboration, report:
Following the detection of GRB 220430A by Swift (Ambrosi et al. GCNC 31972) and AGILE (Ursi et al. GCNC 31975), we triggered the 2.2m CAHA telescope (+ CAFOS) at the Calar Alto Observatory (Almeria, Spain). Images were gathered after the twilight starting on Apr. 30 20:15 UT (i.e. 6.4 hrs post trigger) in Sloan-gri at high airmass. On the co-added Sloan-i band image (8x60s), no optical transient down to 22.1 mag is detected at the X-ray afterglow candidate position reported by Swift/XRT (Ambrosi et al. GCNC 31972, J.P. Osborne et al. GCNC 31973). This non-detection is consistent with the report from Groot et al. (GCNC 31974), Pankov et al.(GCNC 31976), Dornic et al. (GCNC 31977) and V. Lipunov et al.(GCNC 31978).
We thank the staff at Calar Alto observatory for their excellent support.
GCN Circular #31981
S. D. Barthelmy (GSFC), E. Ambrosi (INAF-IASFPA), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team):
Using the data set from T-204 to T+843 sec from the recent telemetry downlink, we report further analysis of BAT GRB 220430A (trigger #1104692) (Ambrosi et al., GCN Circ. 31972). The BAT ground-calculated position is RA, Dec = 97.616, 9.547 deg which is
```
   RA(J2000)  =  06h 30m 27.9s
   Dec(J2000) = +09d 32' 50.1"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows two major pulse emissions. The first one starts at ~T-7 s, peaks at ~T+20 s, and ends at ~T+30 s. It is followed by another larger pulse with several peaks. The largest peak occurs at ~T+42 s. The burst emission ends at ~T+100 s. T90 (15-350 keV) is 43.10 +- 0.57 sec (estimated error including systematics).
The time-averaged spectrum from T-6.53 to T+94.36 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.24 +- 0.02. The fluence in the 15-150 keV band is 4.4 +- 0.05 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+42.00 sec in the 15-150 keV band is 29.6 +- 0.6 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/1104692/BA/
GCN Circular #31987
R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed detection of a long GRB 220430A which was also reported by Swift (Ambrosi et al., GCN 31972; Osborne et al., GCN 31973; Barthelmy et al., GCN 31981), and AGILE (Ursi et al., GCN 31975).
The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2022-04-30 13:53:58.50 UT. The measured peak count rate associated with the burst is 892 (+60, -62) counts/s above the background in the combined data of all the quadrants, with a total of 11896 (+669, -639) counts. The local mean background count rate was 484 (+2, -2) counts/s. Using cumulative rates, we measure a T90 of 40 (+4, -2) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2022-04-30 13:53:58.52 UT. The measured peak count rate is 3131 (+109, -98) counts/s above the background in the combined Veto data of four quadrants, with a total of 48203 (+1134, -1252) counts. The local mean background count rate was 1614 (+3, -5) counts/s. We measure a T90 of 41 (+1, -2) s from the cumulative Veto light curve.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb [1]. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
Links:
------
[1] http://astrosat.iucaa.in/czti/?q=grb
GCN Circular #31997
V. Swain (IITB), H. Kumar (IITB), K. Angail (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA) report on behalf of the GIT team:
We observed GRB 220430A detected by Swift (Ambrosi et al. GCN #31972) and AGILE (Ursi et al. GCN #31975), with a 0.7m GROWTH-India Telescope (GIT). The observation started on 2022-04-30 at 14:23:56 UT, 30.65 min after the SWIFT BAT trigger. We obtained multiple 100-sec exposures in the r' and i' filters. The images were shallower than usual due to poor observing conditions. We did not detect any new source in our stacked image within the 2.0" circle around R.A.= 06h 30m 26.92s, Dec.= +09d 32' 51.1" (J.P. Osborne et al. GCN #31973). The obtained upper limits follow as:
```
-------------------------------------------------------------------
JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) |
-------------------------------------------------------------------
2459700.10382 | 0.60 | 300 (stacked) | r' | > 19.26 | 
2459700.10763 | 0.69 | 300 (stacked) | i' | > 18.68 | 
-------------------------------------------------------------------
```
The upper limits are consistent with the Ambrosi et al., (GCN #31972), Groot et al. (GCN #31974), Pankov et al.(GCNC #31976), Dornic et al. (GCN #31977), V. Lipunov et al.(GCN #31978) and Y.-D. Hu et al. (GCN #31980). The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN Circular #31998
S.Q. Jiang (NAOC), Z.P. Zhu (NAOC,HUST), S.Y. Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220430A detected by Swift (Ambrosi et al., GCN 31972) and AGILE (Ursi et al., GCN 31975) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 13:58:51 UT on 2022-04-30 (i.e., 5.6 min after the BAT trigger), and 3x20, 3x40, 4x60, 12x90 s unfiltered frames were obtained.
No optical source is detected in our stacked image at the XRT position (Osborne et al., GCN 31973), down to a limiting magnitude of ~19.2, calibrated with the Gaia DR2 stars.
GCN Circular #31999
S.Q. Jiang (NAOC), Z.P. Zhu (NAOC,HUST), S.Y. Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220430A detected by Swift (Ambrosi et al., GCN 31972) and AGILE (Ursi et al., GCN 31975) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. Observations started at 14:13:38 UT on 2022-04-30 (i.e., 20.39 min after the BAT trigger). We obtained 3x40, 6x60, 3x90, 6x200 s frames in the Sloan r-band and 3x60,3x90,6x200 s frames in Sloan z-band.
No optical source is detected in our stacked image at the XRT enhanced position (Osborne et al., GCN 31973), with upper limits as follows
```
Tmid-T0 (hr) Filter   UpperLimit (3sigma)
    0.953           r         >20.7
    0.923           z         >19.0
```
calibrated with the nearby PanSTARRS field.

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Jochen Greiner, last update: 06-May-2022 [Disclaimer]