Gamma-ray Burst 230510A

(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 10 May 23 12:06:43 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1167973,   Seg_Num: 0
GRB_RA:          318.156d {+21h 12m 37s} (J2000),
                 318.395d {+21h 13m 35s} (current),
                 317.643d {+21h 10m 34s} (1950)
GRB_DEC:         +34.443d {+34d 26' 33"} (J2000),
                 +34.540d {+34d 32' 23"} (current),
                 +34.236d {+34d 14' 10"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2322 [cnts]    Image_Peak=193 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       11237 [cnts]
BKG_TIME:        43576.74 SOD {12:06:16.74} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20074 TJD;   130 DOY;   23/05/10
GRB_TIME:        43588.58 SOD {12:06:28.58} UT
GRB_PHI:         -17.35 [deg]
GRB_THETA:         8.62 [deg]
SOLN_STATUS:     0x103
RATE_SIGNIF:     21.74 [sigma]
IMAGE_SIGNIF:    10.66 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +1 -18  +0 
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 42"}
SUN_DIST:         79.11 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.27d {+19h 37m 05s}  -26.78d {-26d 46' 49"}
MOON_DIST:        65.44 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       79.89, -9.57 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      335.52, 47.54 [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 matches a source in the ground catalog: IGRJ21117+3427, delta=0.171 [deg].  
COMMENTS:        This is not a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 284.72,5.25 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 10 May 23 12:04:35 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     705413051
GRB_RA:          321.850d {+21h 27m 24s} (J2000),
                 322.104d {+21h 28m 25s} (current),
                 321.306d {+21h 25m 13s} (1950)
GRB_DEC:         +29.250d {+29d 15' 00"} (J2000),
                 +29.352d {+29d 21' 09"} (current),
                 +29.032d {+29d 01' 55"} (1950)
GRB_ERROR:       11.77 [deg radius, statistical plus systematic]
GRB_INTEN:       83 [cnts/sec]
DATA_SIGNIF:     5.40 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20074 TJD;   130 DOY;   23/05/10
GRB_TIME:        43446.93 SOD {12:04:06.93} UT
GRB_PHI:         300.00 [deg]
GRB_THETA:        15.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      1.04
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       1,0,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 41"}
SUN_DIST:         77.27 [deg]   Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN:      294.25d {+19h 36m 59s}  -26.78d {-26d 47' 00"}
MOON_DIST:        62.16 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       78.23,-15.41 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      336.37, 41.51 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_lc_medres34_bn230510503.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 234.15,-4.15 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 10 May 23 12:04:45 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     705413051
GRB_RA:          321.883d {+21h 27m 32s} (J2000),
                 322.138d {+21h 28m 33s} (current),
                 321.339d {+21h 25m 21s} (1950)
GRB_DEC:         +29.233d {+29d 13' 60"} (J2000),
                 +29.336d {+29d 20' 09"} (current),
                 +29.015d {+29d 00' 54"} (1950)
GRB_ERROR:       11.27 [deg radius, statistical plus systematic]
GRB_INTEN:       82 [cnts/sec]
DATA_SIGNIF:     7.90 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        20074 TJD;   130 DOY;   23/05/10
GRB_TIME:        43446.93 SOD {12:04:06.93} UT
GRB_PHI:         300.00 [deg]
GRB_THETA:        15.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.12
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       1,0,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 41"}
SUN_DIST:         77.25 [deg]   Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN:      294.25d {+19h 37m 00s}  -26.78d {-26d 46' 59"}
MOON_DIST:        62.15 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       78.24,-15.45 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      336.40, 41.48 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_lc_medres34_bn230510503.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 234.15,-4.15 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 10 May 23 12:04:54 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     705413051
GRB_RA:          323.120d {+21h 32m 29s} (J2000),
                 323.376d {+21h 33m 30s} (current),
                 322.572d {+21h 30m 17s} (1950)
GRB_DEC:         +28.850d {+28d 51' 00"} (J2000),
                 +28.954d {+28d 57' 15"} (current),
                 +28.628d {+28d 37' 41"} (1950)
GRB_ERROR:       3.08 [deg radius, statistical only]
DATA_SIGNIF:     8.30 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        20074 TJD;   130 DOY;   23/05/10
GRB_TIME:        43446.93 SOD {12:04:06.93} UT
GRB_PHI:         302.00 [deg]
GRB_THETA:        16.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 41"}
SUN_DIST:         76.28 [deg]   Sun_angle= 5.6 [hr] (West of Sun)
MOON_POSTN:      294.25d {+19h 37m 00s}  -26.78d {-26d 46' 58"}
MOON_DIST:        62.34 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       78.74,-16.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      337.49, 40.68 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_lc_medres34_bn230510503.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_705413051.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
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.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:07:57 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1167973,   Seg_Num: 0
GRB_RA:          318.1314d {+21h 12m 31.53s} (J2000),
                 318.3712d {+21h 13m 29.07s} (current),
                 317.6185d {+21h 10m 28.42s} (1950)
GRB_DEC:         +34.4424d {+34d 26' 32.6"} (J2000),
                 +34.5394d {+34d 32' 21.8"} (current),
                 +34.2359d {+34d 14' 09.2"} (1950)
GRB_ERROR:       6.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.19e-08 [erg/cm2/sec]
GRB_SIGNIF:      5.19 [sigma]
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43651.94 SOD {12:07:31.94} UT,   63.4 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.13 261.58 243.69
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 43"}
SUN_DIST:         79.13 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.28d {+19h 37m 08s}  -26.78d {-26d 46' 42"}
MOON_DIST:        65.42 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       79.87, -9.55 [deg] galactic lon,lat of the burst
ECL_COORDS:      335.49, 47.55 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This matches a source in the BAT ground catalog: IGRJ21117+3427, delta=0.151 [deg].
COMMENTS:        The XRT position is 1.20 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:08:04 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1167973,   Seg_Num: 0
GRB_RA:          318.1314d {+21h 12m 31.5s} (J2000),
                 318.3712d {+21h 13m 29.0s} (current),
                 317.6185d {+21h 10m 28.4s} (1950)
GRB_DEC:         +34.4424d {+34d 26' 32.6"} (J2000),
                 +34.5394d {+34d 32' 21.8"} (current),
                 +34.2359d {+34d 14' 09.2"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       27 [cnts]
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43651.94 SOD {12:07:31.94} UT,   63.4 [sec] since BAT Trigger Time
CENTROID_X:      326.96,  raw= 327  [pixels]
CENTROID_Y:      295.00,  raw= 295  [pixels]
ROLL:            75.82 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -7.30
GRB_POS_XRT_Z:   46.11
IMAGE_URL:       sw01167973000msxps_rw.img
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 43"}
SUN_DIST:         79.13 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.29d {+19h 37m 08s}  -26.78d {-26d 46' 42"}
MOON_DIST:        65.42 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       79.87, -9.55 [deg] galactic lon,lat of the burst
ECL_COORDS:      335.49, 47.55 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:08:06 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1167973,   Seg_Num: 0
GRB_RA:          318.1314d {+21h 12m 31.5s} (J2000),
                 318.3712d {+21h 13m 29.0s} (current),
                 317.6185d {+21h 10m 28.4s} (1950)
GRB_DEC:         +34.4424d {+34d 26' 32.6"} (J2000),
                 +34.5394d {+34d 32' 21.8"} (current),
                 +34.2359d {+34d 14' 09.2"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       27 [cnts]
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43651.94 SOD {12:07:31.94} UT,   63.4 [sec] since BAT Trigger Time
CENTROID_X:      326.96,  raw= 327  [pixels]
CENTROID_Y:      295.00,  raw= 295  [pixels]
ROLL:            75.82 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -7.30
GRB_POS_XRT_Z:   46.11
IMAGE_URL:       sw01167973000msxps_rw.img
SUN_POSTN:        47.14d {+03h 08m 34s}  +17.63d {+17d 37' 43"}
SUN_DIST:         79.13 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.29d {+19h 37m 09s}  -26.78d {-26d 46' 41"}
MOON_DIST:        65.42 [deg]
MOON_ILLUM:      74 [%]
GAL_COORDS:       79.87, -9.55 [deg] galactic lon,lat of the burst
ECL_COORDS:      335.49, 47.55 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:10:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.147d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.447d {+34d 26' 47"} (J2000)
POINT_ROLL:      75.827d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43660.59 SOD {12:07:40.59} UT,   72.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.308
N_STARS:         190
X_OFFSET:        536 [pixels]
Y_OFFSET:        576 [pixels]
X_MAX:           1495 [pixels]
Y_MAX:           1535 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw01167973000msufc0072.fits
SUN_POSTN:        47.14d {+03h 08m 35s}  +17.63d {+17d 37' 45"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.31d {+19h 37m 15s}  -26.77d {-26d 46' 29"}
MOON_DIST:        65.42 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:10:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.147d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.447d {+34d 26' 47"} (J2000)
POINT_ROLL:      75.827d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43660.59 SOD {12:07:40.59} UT,   72.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.308
N_STARS:         190
X_OFFSET:        536 [pixels]
Y_OFFSET:        576 [pixels]
X_MAX:           1495 [pixels]
Y_MAX:           1535 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw01167973000msufc0072.fits
SUN_POSTN:        47.15d {+03h 08m 35s}  +17.63d {+17d 37' 45"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.32d {+19h 37m 16s}  -26.77d {-26d 46' 27"}
MOON_DIST:        65.42 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [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 10 May 23 12:12:24 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.147d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.447d {+34d 26' 47"} (J2000)
ROLL:            75.827d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43660.59 SOD {12:07:40.59} UT,   72.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     705413291
X_OFFSET:        722 [pixels]
Y_OFFSET:        932 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       882
Y_GRB_POS:       1092
BINNING_INDEX:   1
IM_URL:          sw01167973000msuni0104.fits
SUN_POSTN:        47.15d {+03h 08m 35s}  +17.63d {+17d 37' 46"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.33d {+19h 37m 20s}  -26.77d {-26d 46' 20"}
MOON_DIST:        65.41 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [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 Circular #33751
The Fermi GBM team reports the detection of a likely LONG GRB
At 12:04:06 UT on 10 May 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230510A (trigger 705413051.934178 / 230510503).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 322.3, Dec = 31.0 (J2000 degrees, equivalent to J2000 21h 29m, 31d 00'), with a statistical uncertainty of 2.6 degrees.
The angle from the Fermi LAT boresight is 14.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_skymap_all_bn230510503.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/bn230510503/quicklook/glg_healpix_all_bn230510503.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230510503/quicklook/glg_lc_medres34_bn230510503.gif

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:13:52 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.146d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.448d {+34d 26' 51"} (J2000)
POINT_ROLL:      75.824d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43872.69 SOD {12:11:12.69} UT,   284.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.171
N_STARS:         83
X_OFFSET:        402 [pixels]
Y_OFFSET:        612 [pixels]
X_MAX:           1361 [pixels]
Y_MAX:           1571 [pixels]
DET_THRESH:      5
PHOTO_THRESH:    2
SL_URL:          sw01167973000msufc0284.fits
SUN_POSTN:        47.15d {+03h 08m 35s}  +17.63d {+17d 37' 47"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.35d {+19h 37m 24s}  -26.77d {-26d 46' 12"}
MOON_DIST:        65.40 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:15:14 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.146d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.448d {+34d 26' 51"} (J2000)
ROLL:            75.824d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43872.69 SOD {12:11:12.69} UT,   284.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     705413503
X_OFFSET:        722 [pixels]
Y_OFFSET:        932 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       882
Y_GRB_POS:       1092
BINNING_INDEX:   1
IM_URL:          sw01167973000msuni0316.fits
SUN_POSTN:        47.15d {+03h 08m 36s}  +17.63d {+17d 37' 48"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.36d {+19h 37m 27s}  -26.77d {-26d 46' 05"}
MOON_DIST:        65.40 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [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 10 May 23 12:12:37 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.147d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.447d {+34d 26' 47"} (J2000)
ROLL:            75.827d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43660.59 SOD {12:07:40.59} UT,   72.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     705413291
X_OFFSET:        722 [pixels]
Y_OFFSET:        932 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       882
Y_GRB_POS:       1092
BINNING_INDEX:   1
IM_URL:          sw01167973000msuni0104.fits
SUN_POSTN:        47.15d {+03h 08m 35s}  +17.63d {+17d 37' 46"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.34d {+19h 37m 20s}  -26.77d {-26d 46' 18"}
MOON_DIST:        65.41 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 10 May 23 12:14:06 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.146d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.448d {+34d 26' 51"} (J2000)
POINT_ROLL:      75.824d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43872.69 SOD {12:11:12.69} UT,   284.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.171
N_STARS:         83
X_OFFSET:        402 [pixels]
Y_OFFSET:        612 [pixels]
X_MAX:           1361 [pixels]
Y_MAX:           1571 [pixels]
DET_THRESH:      5
PHOTO_THRESH:    2
SL_URL:          sw01167973000msufc0284.fits
SUN_POSTN:        47.15d {+03h 08m 35s}  +17.63d {+17d 37' 47"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.35d {+19h 37m 24s}  -26.77d {-26d 46' 11"}
MOON_DIST:        65.40 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [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:     Wed 10 May 23 12:15:22 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1167973,   Seg_Num: 0
POINT_RA:        318.146d {+21h 12m 35s} (J2000)
POINT_DEC:       +34.448d {+34d 26' 51"} (J2000)
ROLL:            75.824d
IMG_START_DATE:  20074 TJD;   130 DOY;   23/05/10
IMG_START_TIME:  43872.69 SOD {12:11:12.69} UT,   284.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     705413503
X_OFFSET:        722 [pixels]
Y_OFFSET:        932 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       882
Y_GRB_POS:       1092
BINNING_INDEX:   1
IM_URL:          sw01167973000msuni0316.fits
SUN_POSTN:        47.15d {+03h 08m 36s}  +17.63d {+17d 37' 48"}
SUN_DIST:         79.12 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      294.37d {+19h 37m 28s}  -26.77d {-26d 46' 04"}
MOON_DIST:        65.40 [deg]
MOON_ILLUM:      73 [%]
GAL_COORDS:       79.88, -9.56 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.51, 47.55 [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 #33752
R. A. J. Eyles-Ferris (U Leicester), P. A. Evans (U Leicester), J.D. Gropp (PSU), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), P. Romano (INAF-OAB), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 12:06:28 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 230510A (trigger=1167973). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 318.156, +34.443 which is
```
   RA(J2000) = 21h 12m 37s
   Dec(J2000) = +34d 26' 33"
```
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 60 sec. The peak count rate was ~5100 counts/sec (15-350 keV), at ~13 sec after the trigger.
The XRT began observing the field at 12:07:31.9 UT, 63.4 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 318.1314, 34.4424 which is equivalent to:
```
   RA(J2000)  = 21h 12m 31.54s
   Dec(J2000) = +34d 26' 32.6"
```
with an uncertainty of 6.5 arcseconds (radius, 90% containment). This location is 73 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
The initial flux in the 0.1 s image was 1.19e-08 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 72 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.144.
This trigger was initially marked as matching a source in the BAT ground catalogue: IGR J21117+3427, a known gamma-ray source. However, the XRT localisation is more than 9 arcmin from the known position of IGR J21117+3427, outside its error region of 3.5 arcmin (ATel 873). This, together with the BAT transient monitor light-curve showing little sign of variation suggests that this is in fact a new GRB.
Burst Advocate for this burst is R. A. J. Eyles-Ferris (raje1 AT leicester.ac.uk). 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 Circular #33756
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1466 s of XRT Photon Counting mode data and 4 UVOT images for GRB 230510A, 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 = 318.13672, +34.44306 which is equivalent to:
```
RA (J2000): 21h 12m 32.81s
Dec (J2000): +34d 26' 35.0"
```
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 #33757
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L. Page (U. Leicester) report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 230510A, from 52 s to 23.0 ks after the BAT trigger. The data comprise 250 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 late-time light curve (from T0+4.2 ks) can be modelled with a power-law decay with a decay index of alpha=0.92 (+/-0.09).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.19 (+/-0.05). The best-fitting absorption column is 2.53 (+0.17, -0.16) x 10^21 cm^-2, in excess of the Galactic value of 1.9 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.99 (+0.13, -0.08) and a best-fitting absorption column of 1.938 (+0.454, -0.025) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.938 (+0.454, -0.025) x 10^21 cm^-2
Galactic foreground: 1.9 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.99 (+0.13, -0.08)
```
If the light curve continues to decay with a power-law decay index of 0.92, the count rate at T+24 hours will be 0.035 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-12 (1.7 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01167973.
This circular is an official product of the Swift-XRT team.
GCN Circular #33761
S.Q. Jiang, T.H. Lu, S.Y. Fu, X. Liu, D. Xu (NAOC), Z.P. Zhu (NAOC, HUST), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 230510A detected by Swift (Eyles-Ferris et al., GCN 33752) and Fermi (Fermi GBM team, GCN 33751) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. Observations started at 18:47:49.1 UT on 2023-05-10, i.e., 6.69 hr after the Swift/BAT trigger, and 12x200 s exposures have been obtained in the Sloan r-filter.
We detected an uncatalogued optical transient (OT) within the enhanced Swift/XRT error circle (Evans et al., GCN 33756) at coordinates
```
R.A. (J2000) = 21:12:32.87
Dec.(J2000) = +34:26:35:59
```
with an uncertainty of ~ 0.5 arcsec, and it has m(r) = 20.5 +/- 0.1 mag in the co-added image at 7.27 hr post-burst, calibrated with the nearby PanSTAR field. PanSTAR covers this position and is much deeper, but the OT is not present. We thus conclude that the OT is the optical afterglow of the burst.
GCN Circular #33762
S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
The long GRB 230510A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 33751; Swift detection: Eyles-Ferris et al., GCN Circ. 33752) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 12:06:22.60 UTC on 10 May 2023 (http://cgbm.calet.jp/cgbm_trigger/flight/1367755544/index.html). The burst signal was seen by all CGBM detectors.
The burst light curve shows a multi-peaked structure that starts at T-139.5 sec, peaks at T+19.6 sec, and ends at T+43.6 sec. The T90 and T50 durations measured by the SGM data are 106.2 +/- 71.3 sec and 13.1 +/- 0.7 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1367755544/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.
GCN Circular #33764
S.Q. Jiang, T.H. Lu, S.Y. Fu, X. Liu, D Xu (NAOC), Z.P. Zhu (NAOC, HUST), S.W. Luo, M.M. Yang, Z. K. Feng (GYZO, NAOC) report:
We observed the field of GRB 230510A detected by Swift (Eyles-Ferris et al., GCN 33752) and Fermi(Fermi GBM team, GCN 33751) with the GOT-0.5m telescope located at Gaoyazi, Xinjiang, China. Observations started at 18:48:27 UT on 2023-05-10, i.e., 6.7 hr after the Swift/BAT trigger, 40 x 90 s images were obtained in the Sloan r filter.
No optical source is detected in our stacked image at the enhanced XRT position (Evans et al., GCN 33756), down to a 3-sigma limiting magnitude r > 19.7 (AB) at 7.27 hr post-burst, calibrated with nearby PanSTARRS stars. The upper limit is consistent with our deeper detection at the Nanshan/NEXT (Jiang et al., GCN 33761).
GCN Circular #33766
C. Malacaria (ISSI) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 12:04:06.93 UT on 10 April 2023, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 230510A (trigger 705413051 / 230510503), which was also detected by the Swift/BAT and Swift/XRT (Eyles-Ferris et al. 2023, GCN 33752; Evans et al. 2023, GCN 33756). The GBM on-ground location is consistent with the Swift position (GCN 33751).
The angle from the Fermi LAT boresight at the GBM trigger time is 14 degrees.
The GBM light curve shows a weaker peak followed about 100 s later by a brighter peak, with a duration (T90) of about 177 s (50-300 keV). The time-averaged spectrum from T0-4.1 s to T0+11.3 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.9 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 87 +/- 7 keV. A Band function fits the spectrum equally well with Epeak = 87 +/- 9 keV, alpha = -0.9 +/- 0.1 and beta = -3.8 +/- 3.2.
The event fluence (10-1000 keV) in this time interval is (2.0 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+158 s in the 10-1000 keV band is 12.4 +/- 0.4 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 #33774
A. Belles (PSU) and R. A. J. Eyles-Ferris (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 230510A 72 s after the BAT trigger (Eyles-Ferris et al., GCN Circ. 33752). A source consistent with the XRT position (Evans et al., GCN Circ. 33756) is detected in the initial UVOT exposures. Preliminary detections and 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
wh_FC               72          222          150      18.90+/-0.10
u_FC               284          318           34      18.09+/-0.32
wh                4413         4613          200      19.33+/-0.11
v                 4824         5024          200      18.97+/-0.32
b                 4209         5690          241      19.31+/-0.17
u                 5439         5638          199      19.10+/-0.24
w1                5234         5434          200      19.30+/-0.34
m2                5029         5228          199            >19.21
w2                4619         4819          200            >19.45
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.144 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #33776
R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on
behalf of a larger collaboration:
We observed the GRB 230510A (Eyles-Ferris et al., GCN 33752) field with the LCOGT 1-meter Sinistro instrument at the Teide Observatory, Tenerife site, on May 11, from 03:03 to 03:36 UT (corresponding to 14.95 to 15.50 hours from the GRB trigger time) with the SDSS r and i filters.
We performed a series of 3x300s exposures in each band. We do not detect a source within the Swift-XRT enhanced error region (Evans et al., GCN 33756) in either band, consistent with fading from the optical afterglow candidate (Jiang et al., GCN 33761).
The following upper limits are calculated using the PanSTARRS catalog as reference:
r > 21.5
i > 19.8
These magnitudes are not corrected for galactic extinction.
GCN Circular #33777
V. Swain (IITB), A. Salgundi (IITB), H. Kumar (IITB), V. Bhalerao (IITB), G.C. Anupama(IIA), S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:
We observed the field of GRB 230510A detected by Fermi (Fermi GBM team, GCN 33751, 33766) and Swift (Eyles-Ferris et al., GCN 33752) with 0.7m GROWTH-India Telescope (GIT). GIT automatically triggered at 19:35:39 UT, i.e., 7.5 hours after the Fermi GBM trigger. We obtained 3 frames of 300s each in the r' band. We search individual images and the stacked image for an afterglow, at the position reported by P.A. Evans et al. (GCN #33756). We do not detect the optical afterglow emission that was detected by S.Q. Jiang et al., (GCN #33761). Our upper limits on the magnitude of the afterglow are:
```
-------------------------------------------------------------------------------------------------------------------      
           JD (mid)           | T_mid-T0(hrs) | Exposure (sec)   | Filter | Lim_mag (5-sigma) |
------------------------------------------------------------------------------------------------------------------- 
 2460075.3164274      |         7.52        |          300            |    r'    |          > 18.77            |
 2460075.32027526    |         7.62        |          300            |    r'    |          > 18.81            |
 2460075.32398713    |         7.71        |          300            |    r'    |          > 18.90            | 
 2460075.320207265  |    7.61 (mid)    | 3x300 (stacked) |    r'    |          > 19.87            |
------------------------------------------------------------------------------------------------------------------
```
The results are consistent with other afterglow observations reported by S.Q. Jiang et al., GCN #33761; S.Q. Jiang et al., GCN #33764; A. Belles et al., GCN #33774; R. Strausbaugh at al., GCN #33776. The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN Circular #33790
B. Schneider (MIT), C. Adami (LAM/Pytheas/AMU), J. T. Palmerio (GEPI,=20 Obs. de Paris), S. Basa (LAM), E. Le Floc'h, D. G=C3=B6tz (CEA Paris-Saclay= ),=20 S. D. Vergani (GEPI, Obs. de Paris), C. Barthelemy, Q. Desvigne,=20 J. Latour (AMU), D. Turpin (CEA Paris-Saclay), report on behalf of a=20 larger collaboration:
We observed the field of GRB 230510A (Fermi GBM team, GCN 33751; Eyles-Ferr= is=20 et al., GCN 33752) using the T193cm and T120cm telescopes at Observatoire d= e=20 Haute-Provence (France) respectively equipped with the MISTRAL spectro-imag= er and the T120 CCD camera. A total of 8 exposures were obtained in the imagin= g=20 mode of MISTRAL in the r-band filter (6x600s + 2x300s) and 50 exposures=20 were obtained with the T120 CCD camera in the r-band filter (50x90s).=20 Observations were made from 2023 11 May 01:24:26 UT to 2023 11 May 03:00:47= UT=20 (mid time ~13.2h after trigger).
In the combined frames, we detect a faint source consistent with the=20 X-ray afterglow position reported by Evans et al. (GCN 33756) and=20 with the optical afterglow position reported by Jiang et al. (GCN 33761).= =20 The source is detected by both instruments at the same position.
Combining the MISTRAL and T120 images, we measured a magnitude of=20 r =3D 21.8 +/- 0.2, in agreement with the value determined individually for each instrument. The faintest PanStarr DR1 object detected at 3 sigma=20 in the combined image is at r =3D 22. The photometric calibration was=20 performed using nearby stars from the PS1 catalog and the magnitude=20 is not corrected for Galactic extinction.
We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen for the MISTRAL observations, Yoann Degot-Longhi, Stephane Favard, Luc Favre, and Christelle Eyraud for the T120 observations.
GCN Circular #33794
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, J.-P. = Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. o= f Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, = M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U.= of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. = Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.= ), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Fris= s (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U= .), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Obse= rvatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Uni= v 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 230510A (Fermi/GBM detection: GCN 33751; Swift/BAT de= tection: GCN 33752; CALET/CGBM detection: GCN 33762; Wind/Konus detection a= t 2023-05-10 12:06:42.814 UT; INTEGRAL/SPI-ACS detection at 2023-05-10 12:0= 6:43 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023; arXiv:23= 02.10048).
The detection was confirmed at the peak time 2023-05-10 12:06:31 UTC. The T90 duration measured by GRBAlpha is 24 s and the overall significance during T90 reaches 6.6 sigma in the 120-400 keV band.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB230510A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN Circular #33880
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), R. A. J. Eyles-Ferris (U Leicester), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+349 sec from the recent telemetry downlink, we report further analysis of BAT GRB 230510A (trigger #1167973) (Eyles-Ferris, et al., GCN Circ. 33752). The BAT ground-calculated position is RA, Dec = 318.138, 34.430 deg which is
```
   RA(J2000)  =  21h 12m 33.2s
   Dec(J2000) = +34d 25' 49.8"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a precursor starting at T-150 s with a duration of ~20 s. The bright main episode starts at T-10 s, peaks at T+15 s, and ends at T+60 s. T90 (15-350 keV) is 178.4 +- 6.9 sec (estimated error including systematics). The time-averaged spectrum from T-145.6 to T+56.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.60 +- 0.09. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+13.39 sec in the 15-150 keV band is 5.9 +- 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/1167973/BA/

Back to JG's homepage

Jochen Greiner, last update: 26-May-2023 [Disclaimer]