Gamma-ray Burst 240123A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:07:01 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1210276,   Seg_Num: 0
GRB_RA:          199.319d {+13h 17m 16s} (J2000),
                 199.548d {+13h 18m 11s} (current),
                 198.841d {+13h 15m 22s} (1950)
GRB_DEC:         +60.632d {+60d 37' 53"} (J2000),
                 +60.505d {+60d 30' 19"} (current),
                 +60.895d {+60d 53' 41"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       24194 [cnts]    Image_Peak=495 [image_cnts]
TRIGGER_DUR:     12.160 [sec] 
TRIGGER_INDEX:   478     E_range: 25-100 keV
BKG_INTEN:       113134 [cnts]
BKG_TIME:        39847.21 SOD {11:04:07.21} UT
BKG_DUR:         64 [sec]
GRB_DATE:        20332 TJD;    23 DOY;   24/01/23
GRB_TIME:        39946.86 SOD {11:05:46.86} UT
GRB_PHI:         116.81 [deg]
GRB_THETA:        31.94 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.32 [sigma]
IMAGE_SIGNIF:    10.84 [sigma]
MERIT_PARAMS:     +1  +0  +0  +4  +2  +0  +0  +0 +41  +0 
SUN_POSTN:       305.22d {+20h 20m 52s}  -19.50d {-19d 30' 03"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.79d {+06h 31m 09s}  +28.18d {+28d 10' 46"}
MOON_DIST:        71.18 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.24, 56.21 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      156.86, 59.78 [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 thetrigger integration 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 = 307.59,20.51 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:08:37 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1210276,   Seg_Num: 0
GRB_RA:          199.3464d {+13h 17m 23.13s} (J2000),
                 199.5756d {+13h 18m 18.15s} (current),
                 198.8686d {+13h 15m 28.46s} (1950)
GRB_DEC:         +60.6174d {+60d 37' 02.6"} (J2000),
                 +60.4911d {+60d 29' 27.9"} (current),
                 +60.8805d {+60d 52' 49.6"} (1950)
GRB_ERROR:       5.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       7.30e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.65 [sigma]
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40088.67 SOD {11:08:08.67} UT,   141.8 [sec] since BAT Trigger
Time
TAM[0-3]:        327.66 237.15 261.58 243.79
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       305.22d {+20h 20m 52s}  -19.50d {-19d 30' 02"}
SUN_DIST:        114.56 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.80d {+06h 31m 12s}  +28.18d {+28d 10' 44"}
MOON_DIST:        71.19 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.21, 56.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      156.90, 59.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.17 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:08:47 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1210276,   Seg_Num: 0
GRB_RA:          199.3464d {+13h 17m 23.1s} (J2000),
                 199.5756d {+13h 18m 18.1s} (current),
                 198.8686d {+13h 15m 28.4s} (1950)
GRB_DEC:         +60.6174d {+60d 37' 02.6"} (J2000),
                 +60.4911d {+60d 29' 27.9"} (current),
                 +60.8805d {+60d 52' 49.6"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       32 [cnts]
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40088.67 SOD {11:08:08.67} UT,   141.8 [sec] since BAT Trigger Time
CENTROID_X:      283.73,  raw= 284  [pixels]
CENTROID_Y:      249.21,  raw= 249  [pixels]
ROLL:            86.10 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -115.22
GRB_POS_XRT_Z:   -55.77
IMAGE_URL:       sw01210276000msxps_rw.img
SUN_POSTN:       305.22d {+20h 20m 52s}  -19.50d {-19d 30' 02"}
SUN_DIST:        114.56 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.80d {+06h 31m 13s}  +28.18d {+28d 10' 44"}
MOON_DIST:        71.19 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.21, 56.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      156.90, 59.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:08:49 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1210276,   Seg_Num: 0
GRB_RA:          199.3464d {+13h 17m 23.1s} (J2000),
                 199.5756d {+13h 18m 18.1s} (current),
                 198.8686d {+13h 15m 28.4s} (1950)
GRB_DEC:         +60.6174d {+60d 37' 02.6"} (J2000),
                 +60.4911d {+60d 29' 27.9"} (current),
                 +60.8805d {+60d 52' 49.6"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       32 [cnts]
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40088.67 SOD {11:08:08.67} UT,   141.8 [sec] since BAT Trigger Time
CENTROID_X:      283.73,  raw= 284  [pixels]
CENTROID_Y:      249.21,  raw= 249  [pixels]
ROLL:            86.10 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -115.22
GRB_POS_XRT_Z:   -55.77
IMAGE_URL:       sw01210276000msxps_rw.img
SUN_POSTN:       305.22d {+20h 20m 52s}  -19.50d {-19d 30' 02"}
SUN_DIST:        114.56 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.80d {+06h 31m 13s}  +28.18d {+28d 10' 43"}
MOON_DIST:        71.19 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.21, 56.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      156.90, 59.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:10:07 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1210276,   Seg_Num: 0
GRB_RA:          199.319d {+13h 17m 16s} (J2000),
                 199.548d {+13h 18m 11s} (current),
                 198.841d {+13h 15m 22s} (1950)
GRB_DEC:         +60.632d {+60d 37' 53"} (J2000),
                 +60.505d {+60d 30' 19"} (current),
                 +60.895d {+60d 53' 41"} (1950)
GRB_DATE:        20332 TJD;    23 DOY;   24/01/23
GRB_TIME:        39946.86 SOD {11:05:46.86} UT
TRIGGER_INDEX:   478
GRB_PHI:         116.81 [deg]
GRB_THETA:        31.94 [deg]
DELTA_TIME:      -43.00 [sec]
TRIGGER_DUR:     12.160 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.32 [sigma]
IMAGE_SIGNIF:    10.84 [sigma]
LC_URL:          sw01210276000msb.lc
SUN_POSTN:       305.22d {+20h 20m 52s}  -19.50d {-19d 30' 02"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.82d {+06h 31m 16s}  +28.18d {+28d 10' 42"}
MOON_DIST:        71.17 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.24, 56.21 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      156.86, 59.78 [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 = 307.59,20.51 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:10:59 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.313d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 52"} (J2000)
POINT_ROLL:      86.098d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40098.44 SOD {11:08:18.44} UT,   151.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.135
N_STARS:         6
X_OFFSET:        552 [pixels]
Y_OFFSET:        656 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1615 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw01210276000msufc0151.fits
SUN_POSTN:       305.22d {+20h 20m 53s}  -19.50d {-19d 30' 01"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.83d {+06h 31m 18s}  +28.18d {+28d 10' 41"}
MOON_DIST:        71.16 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:11:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.313d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 52"} (J2000)
POINT_ROLL:      86.098d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40098.44 SOD {11:08:18.44} UT,   151.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.135
N_STARS:         6
X_OFFSET:        552 [pixels]
Y_OFFSET:        656 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1615 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw01210276000msufc0151.fits
SUN_POSTN:       305.22d {+20h 20m 53s}  -19.50d {-19d 30' 01"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.83d {+06h 31m 18s}  +28.18d {+28d 10' 41"}
MOON_DIST:        71.16 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:12:20 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.313d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 52"} (J2000)
ROLL:            86.098d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40098.44 SOD {11:08:18.44} UT,   151.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     727700931
X_OFFSET:        1002 [pixels]
Y_OFFSET:        1024 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1162
Y_GRB_POS:       1184
BINNING_INDEX:   1
IM_URL:          sw01210276000msuni0184.fits
SUN_POSTN:       305.22d {+20h 20m 53s}  -19.50d {-19d 30' 00"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.84d {+06h 31m 21s}  +28.18d {+28d 10' 39"}
MOON_DIST:        71.15 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:12:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.313d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 52"} (J2000)
ROLL:            86.098d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40098.44 SOD {11:08:18.44} UT,   151.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     727700931
X_OFFSET:        1002 [pixels]
Y_OFFSET:        1024 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1162
Y_GRB_POS:       1184
BINNING_INDEX:   1
IM_URL:          sw01210276000msuni0184.fits
SUN_POSTN:       305.22d {+20h 20m 53s}  -19.50d {-19d 30' 00"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.84d {+06h 31m 22s}  +28.18d {+28d 10' 39"}
MOON_DIST:        71.15 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:24:28 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.311d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 54"} (J2000)
POINT_ROLL:      86.096d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40810.91 SOD {11:20:10.91} UT,   864.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.836
N_STARS:         30
X_OFFSET:        442 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1881 [pixels]
Y_MAX:           1903 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01210276000msufc0864.fits
SUN_POSTN:       305.23d {+20h 20m 55s}  -19.50d {-19d 29' 53"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.96d {+06h 31m 50s}  +28.17d {+28d 10' 25"}
MOON_DIST:        71.10 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:24:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.311d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 54"} (J2000)
POINT_ROLL:      86.096d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40810.91 SOD {11:20:10.91} UT,   864.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.836
N_STARS:         30
X_OFFSET:        442 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1881 [pixels]
Y_MAX:           1903 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01210276000msufc0864.fits
SUN_POSTN:       305.23d {+20h 20m 55s}  -19.50d {-19d 29' 53"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.96d {+06h 31m 50s}  +28.17d {+28d 10' 24"}
MOON_DIST:        71.10 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 23 Jan 24 11:26:11 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.311d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 54"} (J2000)
ROLL:            86.096d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40810.91 SOD {11:20:10.91} UT,   864.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     727701643
X_OFFSET:        1001 [pixels]
Y_OFFSET:        1023 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1161
Y_GRB_POS:       1183
BINNING_INDEX:   1
IM_URL:          sw01210276000msuni0897.fits
SUN_POSTN:       305.23d {+20h 20m 55s}  -19.50d {-19d 29' 52"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.97d {+06h 31m 54s}  +28.17d {+28d 10' 23"}
MOON_DIST:        71.09 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [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:     Tue 23 Jan 24 11:26:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1210276,   Seg_Num: 0
POINT_RA:        199.311d {+13h 17m 15s} (J2000)
POINT_DEC:       +60.648d {+60d 38' 54"} (J2000)
ROLL:            86.096d
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40810.91 SOD {11:20:10.91} UT,   864.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     727701643
X_OFFSET:        1001 [pixels]
Y_OFFSET:        1023 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1161
Y_GRB_POS:       1183
BINNING_INDEX:   1
IM_URL:          sw01210276000msuni0897.fits
SUN_POSTN:       305.23d {+20h 20m 55s}  -19.50d {-19d 29' 52"}
SUN_DIST:        114.58 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       97.98d {+06h 31m 54s}  +28.17d {+28d 10' 22"}
MOON_DIST:        71.09 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.25, 56.19 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      156.83, 59.79 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #35601
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich (Blagoveschensk Educational State University)
MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the Swift GRB240123.46 (trigger No 1210276,13h 17m 16.56s , +60d 37m 55.2s, R=0.05) errorbox 41 sec after notice time and 121 sec after trigger time at 2024-01-23 11:07:48 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenith distance = 68 deg. The sun altitude is -13.5 deg.
The galactic latitude b = 56 deg., longitude l = 117 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2363206
We obtain a following upper limits.

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     131 |        MASTER-Tunka |   C |    20 | 17.6 |        
     160 |        MASTER-Tunka |   C |    20 | 17.6 |        
     186 |        MASTER-Tunka |   C |    15 | 17.5 |        
     209 |        MASTER-Tunka |   C |    15 | 17.5 |        
     229 |        MASTER-Tunka |   C |    10 | 17.4 |        
     247 |        MASTER-Tunka |   C |    10 | 17.3 |        
     265 |        MASTER-Tunka |   C |    10 | 17.4 |        
     284 |        MASTER-Tunka |   C |    10 | 17.1 |        
     302 |        MASTER-Tunka |   C |    10 | 17.4 |        
     320 |        MASTER-Tunka |   C |    10 | 17.5 |        
     339 |        MASTER-Tunka |   C |    10 | 17.4 |        
     357 |        MASTER-Tunka |   C |    10 | 17.3 |        
     375 |        MASTER-Tunka |   C |    10 | 17.5 |        
     394 |        MASTER-Tunka |   C |    10 | 17.4 |        
     412 |        MASTER-Tunka |   C |    10 | 17.2 |        
     430 |        MASTER-Tunka |   C |    10 | 17.4 |        
     448 |        MASTER-Tunka |   C |    10 | 17.3 |        
     466 |        MASTER-Tunka |   C |    10 | 17.4 |        
     486 |        MASTER-Tunka |   C |    10 | 17.4 |        
     504 |        MASTER-Tunka |   C |    10 | 17.4 |        
     522 |        MASTER-Tunka |   C |    10 | 17.4 |        
     541 |        MASTER-Tunka |   C |    10 | 17.4 |        
     559 |        MASTER-Tunka |   C |    10 | 17.4 |        
     577 |        MASTER-Tunka |   C |    10 | 17.4 |        
     595 |        MASTER-Tunka |   C |    10 | 17.4 |        
     613 |        MASTER-Tunka |   C |    10 | 17.4 |        
     632 |        MASTER-Tunka |   C |    10 | 17.4 |        
     651 |        MASTER-Tunka |   C |    10 | 17.4 |        
     669 |        MASTER-Tunka |   C |    10 | 17.4 |        
     706 |        MASTER-Tunka |   C |    10 | 17.4 |        
     724 |        MASTER-Tunka |   C |    10 | 17.4 |        
     743 |        MASTER-Tunka |   C |    10 | 17.4 |        
     761 |        MASTER-Tunka |   C |    10 | 17.5 |        
     781 |        MASTER-Tunka |   C |    10 | 17.4 |        
     799 |        MASTER-Tunka |   C |    10 | 17.5 |

Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35601.

GCN Circular #35602
A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), J.D. Gropp (PSU), J. A. Kennea (PSU), A. Y. Lien (U Tampa), A. Melandri (INAF-OAR), K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII) and B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team:
At 11:05:46 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240123A (trigger=1210276). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 199.319, +60.632 which is
```
   RA(J2000) = 13h 17m 16s
   Dec(J2000) = +60d 37' 53"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 25 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 11:08:08.6 UT, 141.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 199.34797, 60.61894 which is equivalent to:
```
   RA(J2000)  = 13h 17m 23.51s
   Dec(J2000) = +60d 37' 08.2"
```
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 69 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 (1.45 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.7 (+2.69/-2.33) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 7.30e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 151 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	13:17:23.25 = 199.3468
  DEC(J2000) = +60:37:04.4  = 60.6179
```
with a 90%-confidence error radius of about 0.2 arc sec. This position is 4.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 19.9 with a 1-sigma error of about 0.2. No correction has been made for the expected extinction.
Burst Advocate for this burst is A. D'Ai (antonino.dai 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:     Tue 23 Jan 24 11:40:33 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1210276,   Seg_Num: 0
GRB_RA:          199.3479d {+13h 17m 23.49s} (J2000),
                 199.5771d {+13h 18m 18.51s} (current),
                 198.8701d {+13h 15m 28.83s} (1950)
GRB_DEC:         +60.6189d {+60d 37' 08.0"} (J2000),
                 +60.4926d {+60d 29' 33.3"} (current),
                 +60.8820d {+60d 52' 55.0"} (1950)
GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20332 TJD;    23 DOY;   24/01/23
IMG_START_TIME:  40263.00 SOD {11:11:03.00} UT,   316.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       305.24d {+20h 20m 58s}  -19.50d {-19d 29' 44"}
SUN_DIST:        114.57 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       98.12d {+06h 32m 28s}  +28.17d {+28d 10' 05"}
MOON_DIST:        71.06 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      117.21, 56.22 [deg] galactic lon,lat of the burst
ECL_COORDS:      156.90, 59.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #35605
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of GRB 231117A (D'Ai et al., GCN 35602) with AZT-33IK telescope of Mondy observatory in R-filter starting on 2024-01-23 (UT) 14:00:48. We clearly detect a new fading object at coordinates (J2000) 13 17 23.87 +60 37 05.3 with uncertainties of 0.2 arcsec which is slightly differ from coordinates reported by UVOT (D'Ai et al., GCN 35602). The object is absent in SDSS catalogue. Preliminary photometry is following
```
Date       UT start  t-T0     Exp.   Filter   OT     Err.
                   (mid, days)  (s)
2024-01-23 14:00:48  0.126415  7x120 R        19.07  0.10 20.9
2024-01-23 14:20:48  0.144479 13x120 R        19.25  0.10 21.3  
2024-01-23 14:46:49  0.163934 15x120 R        19.37  0.11 21.3  
```
The photometry is based on nearby USNO-B1.0 R2 stars.
GCN Circular #35609
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We continued to observe the afterglow of GRB 240123A (D'Ai et al., GCN 35602) with AZT-33IK telescope of Mondy observatory in R-filter originally started on 2024-01-23 (UT) 14:00:48 (Pankov et al., GCN 35605). We confirm the afterglow decay, which detected previously (D'Ai et al., GCN 35602; Pankov et al., GCN 35605).
Preliminary photometry of the afterglow is following
```
Date       UT start  t-T0     Exp.   Filter   OT     Err. UL(3sigma)
                   (mid, days)  (s)

2024-01-23 16:03:39  0.227009 29x120 R        19.87  0.10 21.9
```
The photometry is based on nearby USNO-B1.0 R2 stars.
We are also reporting the incorrect name of the GRB in GCN Circular No. 35605. The correct name of the GRB in GCN Circular #3560 should be GRB 240123A.
GCN Circular #35610
L. Scotton (UAH) reports on behalf of the Fermi-GBM Team:
Swift-BAT detected GRB 240123A at 11:05:46 UT (D'Ai et al. 2024, GCN 35602). There was no Fermi-GBM onboard trigger around the event.
An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no counterparts.
The GBM targeted search [1], the most sensitive, coherent search for GRB-like signals identified a transient most significantly on the 8.192 s timescale, with a false alarm rate of 3.9e-05 Hz and a location consistent with the Swift-BAT event, using the standard search protocol with a S/N of 13. The GBM targeted search event was found with the highest significance with a "normal" spectrum (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3) for a GRB.
[1] Goldstein et al. 2019 arXiv:1903.12597
GCN Circular #35612
M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), J. D. Gropp (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR) and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 6.5 ks of XRT data for GRB 240123A, from 131 s to 23.7 ks after the BAT trigger. The data comprise 164 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 199.3473, +60.6184 which is equivalent to:
```
RA (J2000): 13 17 23.34
Dec(J2000): +60 37 06.1
```
with an uncertainty of 3.5 arcsec (radius, 90% confidence).
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=7.2 (+0.8, -2.8). At T+145 s the decay flattens to an alpha of 0.3 (+1.0, -1.8). The light curve breaks again at T+183 s to a decay with alpha=2.91 (+0.20, -0.19), before a final break at T+635 s s after which the decay index is 0.58 (+/-0.08).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.35 (+0.09, -0.07). The best-fitting absorption column is consistent with the Galactic value of 1.4 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.01 (+0.17, -0.13) and a best-fitting absorption column of 2.3 (+3.3, -0.9) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.2 x 10^-11 (3.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.3 (+3.3, -0.9) x 10^20 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.01 (+0.17, -0.13)
```
If the light curve continues to decay with a power-law decay index of 0.58, the count rate at T+24 hours will be 0.028 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.0 x 10^-13 (9.6 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01210276.
This circular is an official product of the Swift-XRT team.
GCN Circular #35616
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 596 s of XRT Photon Counting mode data and 1 UVOT images for GRB 240123A, 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 = 199.34861, +60.61849 which is equivalent to:
```
RA (J2000): 13h 17m 23.67s
Dec (J2000): +60d 37' 06.6"
```
with an uncertainty of 2.1 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 #35618
M. Sasada, I. Takahashi, N. Higuchi, M. Niwano, S. Sato, S. Hayatsu, H. Tak= ei, H. Seki, Y. Yatsu and N. Kawai (Tokyo Tech) report on behalf of the MIT= SuME collaboration:
We observed the field of GRB 240123A (D'Ai et al. GCN 35602) with the optic= al three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm t= elescope Akeno.=20
The observation with a series of 60 sec exposures started at 2024-01-23 15:= 09:01 UT (4.05 hours after the Swift/BAT trigger). We stacked the images in= good conditions. An optical candidate of the afterglow can be found at the= location of (RA, Dec) =3D (199.3495, 60.6181) near the Swift/XRT error pos= ition (Capalbi et al. GCN 35612). Here we report magnitudes by the aperture= photometry at the position.
```
T0+[hours] | MID-UT | T-EXP[sec] | magnitudes of aperture photometry
---------------------------------------------------------------------------=
-------------------------------------
5.0 | 2024-01-23 16:05:41 | 5880 | g=E2=80=99=3D19.83+/-0.17, Rc=3D19.35+/-=
0.11, Ic=3D19.24+/-0.13
---------------------------------------------------------------------------=
-------------------------------------
T0+ : Elapsed time after the trigger
T-EXP: Total Exposure time
```
The position of the optical candidate is consistent with Pankov et al., GCN= 35605.
We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1= g, r and i bands were converted to our g'-, Rc- and Ic-band magnitudes fol= lowing Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB= system. The images were processed in real-time through the MITSuME GPU red= uction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; htt= ps://github.com/MNiwano/Eclaire).
GCN Circular #35619
A. S. Moskvitin, O. A. Maslennikova, O. I. Spiridonova (SAO RAS) report on behalf of the GRB follow-up team.
We observed the field of GRB 240123A (D'Ai et al., GCN #35602; Scotton, GCN #35610) with the 1-m telescope of SAO RAS equipped with the CCD photometer. We obtained 12 x 300 sec. images in Rc band on Jan 24, 02:15:54 -- 03:42:02 UT (t_mid - T0 = 0.66194 days).
The OT (D'Ai et al., GCN #35602; Pankov et al., GCNs #35605, #35609; Sasada et al., GCN #35618) is clearly detected in our stacked frame with the brightness of R = 21.12 +/- 0.09.
The photometry is based on R2 magnitudes of nearby USNO-B1 stars.
GCN Circular #35620
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We continued to observe the afterglow of GRB 240123A (D'Ai et al., GCN 35602; Pankov et al., GCN 35605, GCN 35609; Sasada et al., GCN 35618; Moskvitin at al., GCN 35619) with AZT-33IK telescope of Mondy observatory in R-filter.
Using previously reported photometry (Pankov et al., GCN 35605, GCN 35609; Moskvitin at al., GCN 35619) and photometry obtained on t-T0 0.400722 we approximate the light curve with a PL model with the index of PL alpha = -1.1, see Figure at http://grb.rssi.ru/GRB240123A/GRB240123A_LC_approximation.jpg
GCN Circular #35622
T. Parsotan (GSFC), S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+820 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240123A (trigger #1210276) (D'Ai, et al., GCN Circ. 35602). The BAT ground-calculated position is RA, Dec = 199.287, 60.607 deg which is
```
   RA(J2000)  =  13h 17m 08.9s
   Dec(J2000) = +60d 36' 25.6"
```
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 31%.
The mask-weighted light curve shows some weak emission with complex structures that starts at ~T0 and ends at ~T+140 s. The main peak occurs at ~T+5 s. T90 (15-350 keV) is 115.30 +- 54.93 sec (estimated error including systematics).
The time-averaged spectrum from T-0.69 to T+140.46 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.69 +- 0.23. The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+5.49 sec in the 15-150 keV band is 1.1 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1210276/BA/
GCN Circular #35624
A. S. Moskvitin, O. A. Maslennikova, O. I. Spiridonova (SAO RAS) report on behalf of the GRB follow-up team.
We observed the field of GRB 240123A (D'Ai et al., GCN #35602; Scotton, GCN #35610) with the 1-m telescope of SAO RAS equipped with the CCD photometer. We obtained 16 x 300 sec. images in Rc band on Jan 25, 01:55:52 -- 03:30:49 UT (t_mid - T0 = 1.6511 days).
The OT (D'Ai et al., GCN #35602; Pankov et al., GCNs #35605, #35609 #35620; Sasada et al., GCN #35618) is detected in our stacked frame with the brightness of R = 22.0 +/- 0.2.
The photometry is based on R2 magnitudes of nearby USNO-B1.0 stars.
GCN Circular #35628
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner= (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (= Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Sza= kszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Po= valac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r= .o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovs= ky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.)= , Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. B= ozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eot= vos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hi= sadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Ki= ss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.= ), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima = U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo)= , T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 240123A (Swift/BAT detection: GCN 35602; Fermi/GBM de= tection: GCN 35610; INTEGRAL/SPI-ACS peak detection at 2024-01-23 ~11:05:47= ) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; a= rXiv:2302.10048).
The subthreshold detection was confirmed at the peak time 2024-01-23 11:05:= 49 UTC. The T90 duration measured by GRBAlpha is 8 s and the overall signif= icance during T90 reaches 3.5 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.ko= nkoly.hu/static/share/GRB240123A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/he= a/GRBAlpha/=20 GRBAlpha, launched on 2021 March 22, is a demonstration mission for a futur= e CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GR= BAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM ar= ray, covering the energy range from ~50 keV to ~1000 keV. To increase the d= uty cycle and the downlink rate, the upgrade of the on-board data acquisiti= on software stack is in progress. The ground segment is also supported by t= he radio amateur community and it takes advantage of the SatNOGS network fo= r increased data downlink volume.
GCN Circular #35631
C.C. Cheung, M. Kerr, J.E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A.= Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space= Station, reports the detection of GRB 240123A, which was also detected by = Swift/BAT (GCN 35602, 35622), Fermi/GBM (GCN 35610), and GRBAlpha (GCN 3562= 8).
Using an adaptive window with a resolution of 32-ms, the burst onset is det= ermined to be 2024-01-23 11:05:48.840 with a duration of 6.1 s and a total = significance of about 12.2 sigma. The light curve comprises a single peak.
Using a standard power-law function with an exponential high-energy cutoff = [3] to model the emission over this duration results in a photon index dN/d= E~E^x of x=3D-0.4 and a cutoff energy ("Epeak") of 719 keV. The modeled 10= -10000 keV fluence is 1.3e-06 erg/cm^2.
The analysis results presented here are preliminary and use a response func= tion that lacks a detailed characterization of the surrounding passive stru= cture of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program=E2=80=99s STP-H9 to the ISS. The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
```
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
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Jochen Greiner, last update: 27-Jan-2024 [Disclaimer]