Gamma-ray Burst 230405B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 19:58:18 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1163119,   Seg_Num: 0
GRB_RA:          271.467d {+18h 05m 52s} (J2000),
                 271.904d {+18h 07m 37s} (current),
                 270.527d {+18h 02m 07s} (1950)
GRB_DEC:         -47.070d {-47d 04' 12"} (J2000),
                 -47.067d {-47d 03' 59"} (current),
                 -47.075d {-47d 04' 30"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1470 [cnts]    Image_Peak=141 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   124     E_range: 25-100 keV
BKG_INTEN:       12513 [cnts]
BKG_TIME:        71872.94 SOD {19:57:52.94} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20039 TJD;    95 DOY;   23/04/05
GRB_TIME:        71883.50 SOD {19:58:03.50} UT
GRB_PHI:         -102.89 [deg]
GRB_THETA:        11.14 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     22.91 [sigma]
IMAGE_SIGNIF:    9.59 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2  +0  +0  +1 +23  +0 
SUN_POSTN:        14.53d {+00h 58m 08s}   +6.21d {+06d 12' 28"}
SUN_DIST:        103.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.51d {+12h 46m 02s}   -2.68d {-02d 40' 43"}
MOON_DIST:        81.51 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      271.09,-23.64 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 144.49,-14.66 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=702417488).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 05 Apr 23 19:58:33 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     702417488
GRB_RA:          277.233d {+18h 28m 56s} (J2000),
                 277.640d {+18h 30m 34s} (current),
                 276.359d {+18h 25m 26s} (1950)
GRB_DEC:         -40.233d {-40d 13' 59"} (J2000),
                 -40.217d {-40d 12' 59"} (current),
                 -40.266d {-40d 15' 57"} (1950)
GRB_ERROR:       6.48 [deg radius, statistical plus systematic]
GRB_INTEN:       1181 [cnts/sec]
DATA_SIGNIF:     24.90 [sigma]
INTEG_TIME:      0.256 [sec]
GRB_DATE:        20039 TJD;    95 DOY;   23/04/05
GRB_TIME:        71883.87 SOD {19:58:03.87} UT
GRB_PHI:         235.00 [deg]
GRB_THETA:       105.00 [deg]
DATA_TIME_SCALE: 0.2560 [sec]
HARD_RATIO:      0.46
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      91%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,1,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN:        14.53d {+00h 58m 08s}   +6.21d {+06d 12' 28"}
SUN_DIST:         99.26 [deg]   Sun_angle= 6.5 [hr] (West of Sun)
MOON_POSTN:      191.51d {+12h 46m 02s}   -2.68d {-02d 40' 47"}
MOON_DIST:        85.32 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      354.22,-13.17 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      275.77,-16.94 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_lc_medres34_bn230405832.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 41.90,-10.77 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=1163119).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 05 Apr 23 19:58:42 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     702417488
GRB_RA:          288.083d {+19h 12m 20s} (J2000),
                 288.512d {+19h 14m 03s} (current),
                 287.159d {+19h 08m 38s} (1950)
GRB_DEC:         -46.833d {-46d 49' 59"} (J2000),
                 -46.793d {-46d 47' 33"} (current),
                 -46.918d {-46d 55' 02"} (1950)
GRB_ERROR:       4.62 [deg radius, statistical plus systematic]
GRB_INTEN:       1638 [cnts/sec]
DATA_SIGNIF:     85.00 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20039 TJD;    95 DOY;   23/04/05
GRB_TIME:        71883.87 SOD {19:58:03.87} UT
GRB_PHI:         233.00 [deg]
GRB_THETA:       115.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.56
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      91%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,1,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN:        14.53d {+00h 58m 08s}   +6.21d {+06d 12' 28"}
SUN_DIST:         91.81 [deg]   Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN:      191.51d {+12h 46m 02s}   -2.68d {-02d 40' 49"}
MOON_DIST:        92.83 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      350.59,-22.83 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      283.47,-24.24 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_lc_medres34_bn230405832.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 41.90,-10.77 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=1163119).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 05 Apr 23 19:58:52 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     702417488
GRB_RA:          276.860d {+18h 27m 26s} (J2000),
                 277.313d {+18h 29m 15s} (current),
                 275.886d {+18h 23m 33s} (1950)
GRB_DEC:         -50.270d {-50d 16' 11"} (J2000),
                 -50.254d {-50d 15' 13"} (current),
                 -50.301d {-50d 18' 02"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     113.90 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        20039 TJD;    95 DOY;   23/04/05
GRB_TIME:        71883.87 SOD {19:58:03.87} UT
GRB_PHI:         226.00 [deg]
GRB_THETA:       110.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:        14.53d {+00h 58m 08s}   +6.21d {+06d 12' 29"}
SUN_DIST:         99.38 [deg]   Sun_angle= 6.5 [hr] (West of Sun)
MOON_POSTN:      191.51d {+12h 46m 03s}   -2.68d {-02d 40' 51"}
MOON_DIST:        85.25 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      344.57,-16.93 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      274.91,-26.95 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_lc_medres34_bn230405832.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_702417488.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=1163119).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:07:29 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     702417488
GRB_RA:          276.860d {+18h 27m 26s} (J2000),
                 277.313d {+18h 29m 15s} (current),
                 275.886d {+18h 23m 33s} (1950)
GRB_DEC:         -50.270d {-50d 16' 11"} (J2000),
                 -50.254d {-50d 15' 13"} (current),
                 -50.301d {-50d 18' 02"} (1950)
GRB_ERROR:       1.58 [deg radius, statistical only]
GRB_DATE:        20039 TJD;    95 DOY;   23/04/05
GRB_TIME:        71883.87 SOD {19:58:03.87} UT
GRB_PHI:         226.00 [deg]
GRB_THETA:       110.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:        14.54d {+00h 58m 10s}   +6.21d {+06d 12' 37"}
SUN_DIST:         99.39 [deg]   Sun_angle= 6.5 [hr] (West of Sun)
MOON_POSTN:      191.58d {+12h 46m 19s}   -2.72d {-02d 42' 59"}
MOON_DIST:        85.18 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      344.57,-16.93 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      274.91,-26.95 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_lc_medres34_bn230405832.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_locplot_all_bn230405832.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=1163119).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 19:59:38 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1163119,   Seg_Num: 0
GRB_RA:          271.4389d {+18h 05m 45.33s} (J2000),
                 271.8761d {+18h 07m 30.25s} (current),
                 270.4991d {+18h 02m 00.21s} (1950)
GRB_DEC:         -47.0693d {-47d 04' 09.4"} (J2000),
                 -47.0656d {-47d 03' 55.9"} (current),
                 -47.0740d {-47d 04' 26.4"} (1950)
GRB_ERROR:       5.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       9.19e-10 [erg/cm2/sec]
GRB_SIGNIF:      6.24 [sigma]
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  71949.24 SOD {19:59:09.24} UT,   65.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.66 237.11 261.62 243.81
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        14.53d {+00h 58m 08s}   +6.21d {+06d 12' 29"}
SUN_DIST:        103.15 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.52d {+12h 46m 04s}   -2.68d {-02d 41' 03"}
MOON_DIST:        81.48 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.04,-12.35 [deg] galactic lon,lat of the burst
ECL_COORDS:      271.07,-23.64 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.16 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 19:59:48 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
GRB_RA:          271.4389d {+18h 05m 45.3s} (J2000),
                 271.8761d {+18h 07m 30.2s} (current),
                 270.4991d {+18h 02m 00.2s} (1950)
GRB_DEC:         -47.0693d {-47d 04' 09.4"} (J2000),
                 -47.0656d {-47d 03' 55.9"} (current),
                 -47.0740d {-47d 04' 26.4"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       39 [cnts]
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  71949.24 SOD {19:59:09.24} UT,   65.7 [sec] since BAT Trigger Time
CENTROID_X:      345.15,  raw= 345  [pixels]
CENTROID_Y:      295.86,  raw= 296  [pixels]
ROLL:            95.36 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -5.27
GRB_POS_XRT_Z:   89.00
IMAGE_URL:       sw01163119000msxps_rw.img
SUN_POSTN:        14.53d {+00h 58m 08s}   +6.21d {+06d 12' 29"}
SUN_DIST:        103.15 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.52d {+12h 46m 04s}   -2.69d {-02d 41' 05"}
MOON_DIST:        81.47 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.04,-12.35 [deg] galactic lon,lat of the burst
ECL_COORDS:      271.07,-23.64 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:02:12 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.476d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.070d {-47d 04' 12"} (J2000)
POINT_ROLL:      95.361d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  71957.76 SOD {19:59:17.76} UT,   74.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.232
N_STARS:         190
X_OFFSET:        448 [pixels]
Y_OFFSET:        576 [pixels]
X_MAX:           1407 [pixels]
Y_MAX:           1535 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw01163119000msufc0074.fits
SUN_POSTN:        14.54d {+00h 58m 09s}   +6.21d {+06d 12' 32"}
SUN_DIST:        103.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.54d {+12h 46m 09s}   -2.69d {-02d 41' 41"}
MOON_DIST:        81.48 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.06,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:02:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.476d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.070d {-47d 04' 12"} (J2000)
POINT_ROLL:      95.361d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  71957.76 SOD {19:59:17.76} UT,   74.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.232
N_STARS:         190
X_OFFSET:        448 [pixels]
Y_OFFSET:        576 [pixels]
X_MAX:           1407 [pixels]
Y_MAX:           1535 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw01163119000msufc0074.fits
SUN_POSTN:        14.54d {+00h 58m 09s}   +6.21d {+06d 12' 32"}
SUN_DIST:        103.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.54d {+12h 46m 09s}   -2.70d {-02d 41' 44"}
MOON_DIST:        81.48 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.06,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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:     Wed 05 Apr 23 20:03:40 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.476d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.070d {-47d 04' 12"} (J2000)
ROLL:            95.361d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  71957.76 SOD {19:59:17.76} UT,   74.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     702417588
X_OFFSET:        649 [pixels]
Y_OFFSET:        961 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       809
Y_GRB_POS:       1121
BINNING_INDEX:   1
IM_URL:          sw01163119000msuni0106.fits
SUN_POSTN:        14.54d {+00h 58m 09s}   +6.21d {+06d 12' 33"}
SUN_DIST:        103.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.55d {+12h 46m 12s}   -2.70d {-02d 42' 02"}
MOON_DIST:        81.47 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.06,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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:     Wed 05 Apr 23 20:03:50 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1163119,   Seg_Num: 0
GRB_RA:          271.467d {+18h 05m 52s} (J2000),
                 271.904d {+18h 07m 37s} (current),
                 270.527d {+18h 02m 07s} (1950)
GRB_DEC:         -47.070d {-47d 04' 12"} (J2000),
                 -47.067d {-47d 03' 59"} (current),
                 -47.075d {-47d 04' 30"} (1950)
GRB_DATE:        20039 TJD;    95 DOY;   23/04/05
GRB_TIME:        71883.50 SOD {19:58:03.50} UT
TRIGGER_INDEX:   124
GRB_PHI:         -102.89 [deg]
GRB_THETA:        11.14 [deg]
DELTA_TIME:      64.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     22.91 [sigma]
IMAGE_SIGNIF:    9.59 [sigma]
LC_URL:          sw01163119000msb.lc
SUN_POSTN:        14.54d {+00h 58m 09s}   +6.21d {+06d 12' 33"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.55d {+12h 46m 12s}   -2.70d {-02d 42' 05"}
MOON_DIST:        81.46 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      271.09,-23.64 [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 = 144.49,-14.66 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:03:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.476d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.070d {-47d 04' 12"} (J2000)
ROLL:            95.361d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  71957.76 SOD {19:59:17.76} UT,   74.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     702417588
X_OFFSET:        649 [pixels]
Y_OFFSET:        961 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       809
Y_GRB_POS:       1121
BINNING_INDEX:   1
IM_URL:          sw01163119000msuni0106.fits
SUN_POSTN:        14.54d {+00h 58m 09s}   +6.21d {+06d 12' 33"}
SUN_DIST:        103.13 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.55d {+12h 46m 12s}   -2.70d {-02d 42' 06"}
MOON_DIST:        81.46 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.06,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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 Circular #33570
The Fermi GBM team reports the detection of a likely LONG GRB
At 19:58:03 UT on 5 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230405B (trigger 702417488.872428 / 230405832).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 276.9, Dec = -50.3 (J2000 degrees, equivalent to J2000 18h 27m, -50d 17'), with a statistical uncertainty of 1.6 degrees.
The angle from the Fermi LAT boresight is 110.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_skymap_all_bn230405832.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_healpix_all_bn230405832.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230405832/quicklook/glg_lc_medres34_bn230405832.gif
GCN Circular #33571
K. L. Page (U Leicester), C. Gronwall (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU), M. J. Moss (GWU), D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 19:58:03 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 230405B (trigger=1163119). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 271.467, -47.070 which is
```
   RA(J2000) = 18h 05m 52s
   Dec(J2000) = -47d 04' 12"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 10 sec. The peak count rate was ~16000 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 19:59:09.2 UT, 65.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 271.44108, -47.06898 which is equivalent to:
```
   RA(J2000)  = 18h 05m 45.86s
   Dec(J2000) = -47d 04' 08.3"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 63 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density.
The initial flux in the 2.5 s image was 9.19e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 74 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. No correction has been made for the expected extinction corresponding to E(B-V) of 0.166.
Burst Advocate for this burst is K. L. Page (kimlpage1978 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:     Wed 05 Apr 23 20:18:57 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.474d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 14"} (J2000)
POINT_ROLL:      95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72749.98 SOD {20:12:29.98} UT,   866.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.997
N_STARS:         190
X_OFFSET:        89 [pixels]
Y_OFFSET:        401 [pixels]
X_MAX:           1528 [pixels]
Y_MAX:           1840 [pixels]
DET_THRESH:      21
PHOTO_THRESH:    12
SL_URL:          sw01163119000msufc0866.fits
SUN_POSTN:        14.55d {+00h 58m 11s}   +6.21d {+06d 12' 48"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.67d {+12h 46m 40s}   -2.76d {-02d 45' 48"}
MOON_DIST:        81.34 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:19:10 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.474d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 14"} (J2000)
POINT_ROLL:      95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72749.98 SOD {20:12:29.98} UT,   866.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.997
N_STARS:         190
X_OFFSET:        89 [pixels]
Y_OFFSET:        401 [pixels]
X_MAX:           1528 [pixels]
Y_MAX:           1840 [pixels]
DET_THRESH:      21
PHOTO_THRESH:    12
SL_URL:          sw01163119000msufc0866.fits
SUN_POSTN:        14.55d {+00h 58m 11s}   +6.21d {+06d 12' 48"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.67d {+12h 46m 41s}   -2.76d {-02d 45' 51"}
MOON_DIST:        81.34 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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:     Wed 05 Apr 23 20:19:52 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1163119,   Seg_Num: 0
GRB_RA:          271.4409d {+18h 05m 45.81s} (J2000),
                 271.8781d {+18h 07m 30.73s} (current),
                 270.5011d {+18h 02m 00.26s} (1950)
GRB_DEC:         -47.0696d {-47d 04' 10.5"} (J2000),
                 -47.0659d {-47d 03' 57.0"} (current),
                 -47.0743d {-47d 04' 27.5"} (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:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72203.00 SOD {20:03:23.00} UT,   319.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        14.55d {+00h 58m 11s}   +6.21d {+06d 12' 48"}
SUN_DIST:        103.17 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.67d {+12h 46m 42s}   -2.77d {-02d 46' 02"}
MOON_DIST:        81.31 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.04,-12.35 [deg] galactic lon,lat of the burst
ECL_COORDS:      271.07,-23.64 [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 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:21:12 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.474d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 14"} (J2000)
ROLL:            95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72749.98 SOD {20:12:29.98} UT,   866.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     702418381
X_OFFSET:        648 [pixels]
Y_OFFSET:        960 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       808
Y_GRB_POS:       1120
BINNING_INDEX:   1
IM_URL:          sw01163119000msuni0898.fits
SUN_POSTN:        14.55d {+00h 58m 12s}   +6.21d {+06d 12' 50"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.69d {+12h 46m 44s}   -2.77d {-02d 46' 21"}
MOON_DIST:        81.32 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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:     Wed 05 Apr 23 20:21:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.474d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 14"} (J2000)
ROLL:            95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72749.98 SOD {20:12:29.98} UT,   866.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     702418381
X_OFFSET:        648 [pixels]
Y_OFFSET:        960 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       808
Y_GRB_POS:       1120
BINNING_INDEX:   1
IM_URL:          sw01163119000msuni0898.fits
SUN_POSTN:        14.55d {+00h 58m 12s}   +6.21d {+06d 12' 50"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.69d {+12h 46m 45s}   -2.77d {-02d 46' 24"}
MOON_DIST:        81.32 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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 #33572
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 230405B, we find an enhanced XRT position of the afterglow: RA, Dec: 271.44100, -47.06977 which is equivalent to:
```
   RA (J2000)  = 18 05 45.84
   Dec (J2000) = -47 04 11.2
```
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/1163119.
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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:10:31 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.473d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 15"} (J2000)
POINT_ROLL:      95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72169.99 SOD {20:02:49.99} UT,   286.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.101
N_STARS:         190
X_OFFSET:        329 [pixels]
Y_OFFSET:        641 [pixels]
X_MAX:           1288 [pixels]
Y_MAX:           1600 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw01163119000msufc0286.fits
SUN_POSTN:        14.54d {+00h 58m 10s}   +6.21d {+06d 12' 40"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.60d {+12h 46m 24s}   -2.73d {-02d 43' 44"}
MOON_DIST:        81.41 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 05 Apr 23 20:11:53 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.473d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 15"} (J2000)
ROLL:            95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72169.99 SOD {20:02:49.99} UT,   286.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     702417801
X_OFFSET:        649 [pixels]
Y_OFFSET:        961 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       809
Y_GRB_POS:       1121
BINNING_INDEX:   1
IM_URL:          sw01163119000msuni0318.fits
SUN_POSTN:        14.54d {+00h 58m 10s}   +6.21d {+06d 12' 41"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.61d {+12h 46m 27s}   -2.73d {-02d 44' 04"}
MOON_DIST:        81.40 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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:     Wed 05 Apr 23 20:10:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.473d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 15"} (J2000)
POINT_ROLL:      95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72169.99 SOD {20:02:49.99} UT,   286.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.101
N_STARS:         190
X_OFFSET:        329 [pixels]
Y_OFFSET:        641 [pixels]
X_MAX:           1288 [pixels]
Y_MAX:           1600 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw01163119000msufc0286.fits
SUN_POSTN:        14.54d {+00h 58m 10s}   +6.21d {+06d 12' 40"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.60d {+12h 46m 25s}   -2.73d {-02d 43' 47"}
MOON_DIST:        81.41 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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:     Wed 05 Apr 23 20:12:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1163119,   Seg_Num: 0
POINT_RA:        271.473d {+18h 05m 54s} (J2000)
POINT_DEC:       -47.071d {-47d 04' 15"} (J2000)
ROLL:            95.364d
IMG_START_DATE:  20039 TJD;    95 DOY;   23/04/05
IMG_START_TIME:  72169.99 SOD {20:02:49.99} UT,   286.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     702417801
X_OFFSET:        649 [pixels]
Y_OFFSET:        961 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       809
Y_GRB_POS:       1121
BINNING_INDEX:   1
IM_URL:          sw01163119000msuni0318.fits
SUN_POSTN:        14.54d {+00h 58m 10s}   +6.21d {+06d 12' 41"}
SUN_DIST:        103.14 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      191.61d {+12h 46m 27s}   -2.74d {-02d 44' 05"}
MOON_DIST:        81.40 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      346.05,-12.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      271.10,-23.64 [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 Circular #33573
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-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 230405B ( K. L. Page et al., GCN 33571) errorbox 4283 sec after notice time and 4302 sec after trigger time at 2023-04-05 21:09:46 UT, with upper limit up to 16.0 mag. The observations began at zenith distance = 73 deg. The sun altitude is -56.4 deg.
The galactic latitude b = -13 deg., longitude l = 346 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2208901
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

    4393 |         MASTER-SAAO | P\\ |   180 | 16.0 |        
    4393 |         MASTER-SAAO |  P/ |   180 | 16.0 |        
```
The observation and reduction will continue. The message may be cited.
GCN Circular #33574
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 1065 s of XRT Photon Counting mode data and 1 UVOT images for GRB 230405B, 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 = 271.44062, -47.06983 which is equivalent to:
```
RA (J2000): 18h 05m 45.75s
Dec (J2000): -47d 04' 11.4"
```
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 #33575
P K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/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 the detection of a long GRB 230405B which was also detected by Fermi (Fermi GBM Team, GCN 33570), and Swift (Page et al., GCN 33571).
The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-04-05 19:58:05.65 UTC. The measured peak count rate associated with the burst is 894 (+200, -92) counts/s above the background in the combined data of three quadrants (out of four), with a total of 1098 (+189, -189) counts. The local mean background count rate was 336 (+8, -10) counts/s. Using cumulative rates, we measure a T90 of 4.3 (+1.0, -1.7) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-04-05 19:58:05.12 UTC. The measured peak count rate associated with the burst is 1564 (+88, -98) counts/s above the background in the combined data of all quadrants, with a total of 3078 (+369, -404) counts. The local mean background count rate was 1466 (+5, -6) counts/s. We measure a T90 of 4.1 (+5.1, -1.5) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb
GCN Circular #33576
S. R. Oates (U. Birmingham) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230405B 75 s after the BAT trigger (Page et al., GCN Circ. 33571). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 33574) 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            75          224          147         >20.5
u_FC               287          537          246         >19.7
white               75         1363          373         >20.7
v                  618         4860          274         >19.1
b                  542         1339           78         >19.0
u                  287         1313          304         >19.7
w1                 668         1289           78         >18.5
m2                 642         5065          274         >19.4
w2                 593         1389           97         >18.8
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.166 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #33582
S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO), P.M. Vreeswijk (Radboud), D. Pieterse (Radboud) and D.B. Malesani (Radboud and DAWN/NBI) report on behalf of the MeerLICHT consortium:
Following the detection of GRB 230405B by Swift/BAT along with its X-ray counterpart (Page et al., GCN 33571), the 0.6 m wide-field MeerLICHT optical telescope located at Sutherland, South Africa, obtained a repeated series of 60-s exposures in the q,u,g,r,i,z bands following the sequence quqgqrqiqz. Observations began 6.38 hours after the Swift trigger at 2023 April 6 02:20:05 UT and continued for a further 1.82 hours.
Our individual 60-s exposures show no new optical source consistent with the enhanced XRT position (Beardmore et al., GCN 33574) when compared to archival DECam images of this field. We therefore co-added the images in each filter in order to obtain deeper limits. We report the following 3-sigma AB magnitude limits at the XRT position at ~7.2 hours post-trigger:
```
u > 20.5
g > 21.3
q > 22.6
r > 21.2
i > 21.1
z > 20.1
```
MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.
GCN Circular #33583
J. Wood (NASA/MSFC) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 19:58:03 UT on 05 April 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230405B (trigger 702417488/230405832). which was also detected by the Swift/BAT and Swift/XRT (K. L. Page et al. 2023, GCN 33571). The Fermi GBM on-ground location is consistent with the Swift XRT position.
The angle from the Fermi LAT boresight is 105 degrees.
The GBM light curve consists of a single pulse with a duration (T90) of about 4.3 s (50-300 keV). The time-averaged spectrum from T0+0.0 to T0+5.1 s is best fit by a Band function with Epeak = 225 +/- 11 keV, alpha = -0.53 +/- 0.05, and beta = -2.4 +/- 0.1.
The event fluence (10-1000 keV) in this time interval is (1.2 +/- 0.2)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.5 s in the 10-1000 keV band is 27.5 +/- 0.5 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular #33584
P.A. Evans (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU), J. D. Gropp (PSU), J.P. Osborne (U. Leicester) and K.L. Page report on behalf of the Swift-XRT team:
We have analysed 6.5 ks of XRT data for GRB 230405B (Page et al. GCN Circ. 33571), from 54 s to 75.0 ks after the BAT trigger. The data comprise 246 s in Windowed Timing (WT) mode (the first 10 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 Beardmore et al. (GCN Circ. 33572).
The light curve can be modelled with an initial power-law decay with an index of alpha=0.88 (+/-0.04), followed by a break at T+937 s to an alpha of 1.14 (+0.16, -0.05).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.10 (+0.12, -0.11). The best-fitting absorption column is 4.0 (+0.6, -0.5) x 10^21 cm^-2, in excess of the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.95 (+0.17, -0.16) and a best-fitting absorption column of 5.4 (+1.1, -1.0) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x 10^-11 (6.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     5.4 (+1.1, -1.0) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: 6.2 sigma
Photon index:	     1.95 (+0.17, -0.16)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01163119.
This circular is an official product of the Swift-XRT team.
GCN Circular #33585
C. Casentini, M. Cardillo (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS and Uni. Roma Tor Vergata), F. Lucarelli, F. Verrecchia(SSDC, and INAF/OAR), A. Argan, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS), A. Addis, L. Baroncelli, A. Bulgarelli, A. Di Piano, V. Fioretti, G.Panebianco, N. Parmiggiani (INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi (INAF/OAS-Bologna, Bergen University), M. Pilia, A. Trois (INAF/OA Cagliari), I. Donnarumma, E. Menegoni, A.Ursi (ASI), A. Giuliani (INAF/IASF-Mi) and P. Tempesta (TeleSpazio), report on behalf of the AGILE Team:
The AGILE satellite detected the GRB 230405B at T0 = 2023-04-05 19:58:03 s (UTC), reported by Fermi (GCNs #33570, #33583), Swift (GCNs #33571, #33572, #33574, #33576, #33584), AstroSat CZTI (GCN #33575), MeerLICHT (GCN #33582), and Global MASTER-Net (GCN #33573).
The burst is clearly visible in the AGILE scientific ratemeters of the MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors. The event lasted about 5 s and it released a total number of 3105 counts in the MCAL detector (above a background rate of 539 Hz), and 16691 counts in AC-Top detector (above a background rate of 2650 Hz). The AGILE ratemeters light curves can be found at http://www.agilescienceapp.it/notices/GRB230405B_AGILE_RM_ND.png .
At the T0, the event was 83 deg off-axis.
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
<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Privo di virus.www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
GCN Circular #33586
A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long-duration GRB 230405B (Fermi-GBM detection: The Fermi GBM team, GCN 33570; Wood & Meegan, GCN 33583; Swift-BAT detection: Page et al., GCN 33571; AstroSat CZTI detection: Navaneeth et al., GCN 33575; AGILE detection: Casentini et al., GCN 33585) triggered Konus-Wind at T0=71884.77 s UT (19:58:04.770).
The burst light curve shows a single pulse, which starts at ~T0-6.1 s and has a total duration of ~10.7 s. The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB230405_T71884/
As observed by Konus-Wind, the burst had a fluence of 2.24(-0.23,+0.27)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+1.088 s, of 9.76(-1.97,+2.26)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.37(-0.26,+0.30), the high energy photon index beta = -2.75(-0.64,+0.31), the peak energy Ep = 184(-20,+23) keV (chi2 = 101/91 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #33590
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration.
The long duration GRB 230405B (Fermi/GBM detection: GCN 33570; Swift/BAT detection: GCN 33571; AstroSat detection: GCN 33575; AGILE detection: GCN 33585; Konus/Wind detection: GCN 33586; INTEGRAL/SPI-ACS detection at 2023-04-05 19:58:04) was detected by the GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).
The data acquisition was performed by the GRB detector unit no. 1 and the detection was confirmed at the peak time 2023-04-05 19:58:04 UTC. The T90 duration was measured to be 3 s with the light curve resolution of 1 s. The significance during T90 reaches 25 sigma.
The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB230405B_GCN_VZLUSAT2.pdf
All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.

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Jochen Greiner, last update: 07-Apr-2023 [Disclaimer]