Gamma-ray Burst 241025A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:37:17 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.330d {+22h 13m 19s} (J2000),
                 333.090d {+22h 12m 22s} (current),
                 333.767d {+22h 15m 04s} (1950)
GRB_DEC:         +83.566d {+83d 33' 59"} (J2000),
                 +83.690d {+83d 41' 23"} (current),
                 +83.317d {+83d 19' 01"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5794 [cnts]    Image_Peak=238 [image_cnts]
TRIGGER_DUR:     2.048 [sec] 
TRIGGER_INDEX:   271     E_range: 50-350 keV
BKG_INTEN:       51659 [cnts]
BKG_TIME:        5773.58 SOD {01:36:13.58} UT
BKG_DUR:         24 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5810.57 SOD {01:36:50.57} UT
GRB_PHI:         -31.66 [deg]
GRB_THETA:        39.32 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     13.26 [sigma]
IMAGE_SIGNIF:    9.01 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +3  -1  +0  +0 +27  +0 
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 48"}
SUN_DIST:        105.60 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.45d {+08h 57m 47s}  +21.79d {+21d 47' 30"}
MOON_DIST:        74.20 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       74.00, 68.70 [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 = 323.63,16.81 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(24.0<100sec) coincident with the FERMI_GBM event (trignum=751512991).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:37:15 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     751512991
GRB_RA:           37.970d {+02h 31m 53s} (J2000),
                  38.674d {+02h 34m 42s} (current),
                  36.580d {+02h 26m 19s} (1950)
GRB_DEC:         +77.440d {+77d 26' 24"} (J2000),
                 +77.548d {+77d 32' 54"} (current),
                 +77.218d {+77d 13' 06"} (1950)
GRB_ERROR:       12.81 [deg radius, statistical only]
DATA_SIGNIF:     6.50 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         211.00 [deg]
GRB_THETA:        58.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 48"}
SUN_DIST:        114.51 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      134.45d {+08h 57m 47s}  +21.79d {+21d 47' 31"}
MOON_DIST:        69.98 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      128.43, 15.65 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       71.45, 57.38 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_751512991.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/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:37:26 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      72
TRIGGER_NUM:     751512991
GRB_RA:          316.950d {+21h 07m 48s} (J2000),
                 316.391d {+21h 05m 34s} (current),
                 318.008d {+21h 12m 02s} (1950)
GRB_DEC:         +83.783d {+83d 46' 60"} (J2000),
                 +83.884d {+83d 53' 02"} (current),
                 +83.578d {+83d 34' 41"} (1950)
GRB_ERROR:       11.07 [deg radius, statistical plus systematic]
GRB_INTEN:       144 [cnts/sec]
DATA_SIGNIF:     15.90 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         209.00 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.38
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      93%  GRB
2nd_MOST_LIKELY:   3%  Cyg X-1
DETECTORS:       0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 48"}
SUN_DIST:        103.88 [deg]   Sun_angle= -7.1 [hr] (East of Sun)
MOON_POSTN:      134.45d {+08h 57m 48s}  +21.79d {+21d 47' 29"}
MOON_DIST:        74.32 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      117.32, 23.53 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       76.42, 70.30 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 142.78,7.25 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(24.0<100sec) coincident with the SWIFT_BAT event (trignum=1262165).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:37:12 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      68
TRIGGER_NUM:     751512991
GRB_RA:          316.950d {+21h 07m 48s} (J2000),
                 316.393d {+21h 05m 34s} (current),
                 318.003d {+21h 12m 01s} (1950)
GRB_DEC:         +83.767d {+83d 46' 00"} (J2000),
                 +83.867d {+83d 52' 02"} (current),
                 +83.561d {+83d 33' 41"} (1950)
GRB_ERROR:       14.52 [deg radius, statistical plus systematic]
GRB_INTEN:       142 [cnts/sec]
DATA_SIGNIF:     10.60 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         209.00 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.46
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      92%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 48"}
SUN_DIST:        103.88 [deg]   Sun_angle= -7.1 [hr] (East of Sun)
MOON_POSTN:      134.45d {+08h 57m 47s}  +21.79d {+21d 47' 31"}
MOON_DIST:        74.34 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      117.30, 23.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       76.38, 70.31 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 142.78,7.25 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:36:57 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      47
TRIGGER_NUM:     751512991
GRB_RA:          277.600d {+18h 30m 24s} (J2000),
                 273.567d {+18h 14m 16s} (current),
                 285.426d {+19h 01m 42s} (1950)
GRB_DEC:         +88.183d {+88d 10' 60"} (J2000),
                 +88.197d {+88d 11' 48"} (current),
                 +88.127d {+88d 07' 38"} (1950)
GRB_ERROR:       24.08 [deg radius, statistical plus systematic]
GRB_INTEN:       80 [cnts/sec]
DATA_SIGNIF:     6.40 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         216.00 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.85
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   2%  Cyg X-1
DETECTORS:       0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 48"}
SUN_DIST:        101.41 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:      134.44d {+08h 57m 47s}  +21.79d {+21d 47' 34"}
MOON_DIST:        69.58 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      120.90, 27.28 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       89.35, 68.36 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 142.78,7.25 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:38:35 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      2
TRIGGER_NUM:     751512991
GRB_RA:          314.470d {+20h 57m 53s} (J2000),
                 314.216d {+20h 56m 52s} (current),
                 314.957d {+20h 59m 50s} (1950)
GRB_DEC:         +80.150d {+80d 09' 00"} (J2000),
                 +80.247d {+80d 14' 48"} (current),
                 +79.954d {+79d 57' 15"} (1950)
GRB_ERROR:       4.44 [deg radius, statistical only]
DATA_SIGNIF:     20.50 [sigma]
DATA_INTERVAL:   12.288 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         204.00 [deg]
GRB_THETA:        44.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 49"}
SUN_DIST:        104.44 [deg]   Sun_angle= -7.0 [hr] (East of Sun)
MOON_POSTN:      134.46d {+08h 57m 50s}  +21.79d {+21d 47' 17"}
MOON_DIST:        77.97 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      113.91, 21.68 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       66.82, 72.27 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_751512991.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
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(24.0<100sec) coincident with the SWIFT_BAT event (trignum=1262165).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:38:24 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     751512991
GRB_RA:          303.470d {+20h 13m 53s} (J2000),
                 303.155d {+20h 12m 37s} (current),
                 304.083d {+20h 16m 20s} (1950)
GRB_DEC:         +79.620d {+79d 37' 12"} (J2000),
                 +79.696d {+79d 41' 45"} (current),
                 +79.465d {+79d 27' 55"} (1950)
GRB_ERROR:       5.65 [deg radius, statistical only]
DATA_SIGNIF:     16.70 [sigma]
DATA_INTERVAL:   8.192 [sec]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         204.00 [deg]
GRB_THETA:        42.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 49"}
SUN_DIST:        102.59 [deg]   Sun_angle= -6.2 [hr] (East of Sun)
MOON_POSTN:      134.46d {+08h 57m 50s}  +21.79d {+21d 47' 19"}
MOON_DIST:        78.33 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      112.37, 23.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       68.59, 74.21 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_751512991.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
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(24.0<100sec) coincident with the SWIFT_BAT event (trignum=1262165).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:45:54 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     751512991
GRB_RA:          326.240d {+21h 44m 58s} (J2000),
                 326.105d {+21h 44m 25s} (current),
                 326.491d {+21h 45m 58s} (1950)
GRB_DEC:         +80.300d {+80d 17' 60"} (J2000),
                 +80.415d {+80d 24' 53"} (current),
                 +80.068d {+80d 04' 05"} (1950)
GRB_ERROR:       3.61 [deg radius, statistical only]
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5786.89 SOD {01:36:26.89} UT
GRB_PHI:         204.00 [deg]
GRB_THETA:        46.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       209.96d {+13h 59m 51s}  -12.22d {-12d 12' 55"}
SUN_DIST:        106.28 [deg]   Sun_angle= -7.7 [hr] (East of Sun)
MOON_POSTN:      134.52d {+08h 58m 06s}  +21.77d {+21d 46' 03"}
MOON_DIST:        77.63 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      115.43, 20.27 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       65.42, 70.32 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_locplot_all_bn241025067.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:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(24.0<100sec) coincident with the SWIFT_BAT event (trignum=1262165).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:39:21 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.6488d {+22h 14m 35.7s} (J2000),
                 333.4148d {+22h 13m 39.5s} (current),
                 334.0757d {+22h 16m 18.1s} (1950)
GRB_DEC:         +83.5739d {+83d 34' 26.0"} (J2000),
                 +83.6976d {+83d 41' 51.2"} (current),
                 +83.3239d {+83d 19' 26.1"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       156 [cnts]
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5926.26 SOD {01:38:46.26} UT,   115.7 [sec] since BAT Trigger Time
CENTROID_X:      351.11,  raw= 351  [pixels]
CENTROID_Y:      261.46,  raw= 261  [pixels]
ROLL:            302.03 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -87.77
GRB_POS_XRT_Z:   93.14
IMAGE_URL:       sw01262165000msxps_rw.img
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 50"}
SUN_DIST:        105.63 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.47d {+08h 57m 52s}  +21.79d {+21d 47' 09"}
MOON_DIST:        74.19 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.55, 22.08 [deg] galactic lon,lat of the burst
ECL_COORDS:       74.00, 68.67 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:39:26 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.6488d {+22h 14m 35.7s} (J2000),
                 333.4148d {+22h 13m 39.5s} (current),
                 334.0757d {+22h 16m 18.1s} (1950)
GRB_DEC:         +83.5739d {+83d 34' 26.0"} (J2000),
                 +83.6976d {+83d 41' 51.2"} (current),
                 +83.3239d {+83d 19' 26.1"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       156 [cnts]
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5926.26 SOD {01:38:46.26} UT,   115.7 [sec] since BAT Trigger Time
CENTROID_X:      351.11,  raw= 351  [pixels]
CENTROID_Y:      261.46,  raw= 261  [pixels]
ROLL:            302.03 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -87.77
GRB_POS_XRT_Z:   93.14
IMAGE_URL:       sw01262165000msxps_rw.img
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 50"}
SUN_DIST:        105.63 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.47d {+08h 57m 52s}  +21.79d {+21d 47' 08"}
MOON_DIST:        74.19 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.55, 22.08 [deg] galactic lon,lat of the burst
ECL_COORDS:       74.00, 68.67 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:39:11 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.6488d {+22h 14m 35.71s} (J2000),
                 333.4148d {+22h 13m 39.54s} (current),
                 334.0757d {+22h 16m 18.16s} (1950)
GRB_DEC:         +83.5739d {+83d 34' 26.0"} (J2000),
                 +83.6976d {+83d 41' 51.2"} (current),
                 +83.3239d {+83d 19' 26.1"} (1950)
GRB_ERROR:       4.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       5.63e-09 [erg/cm2/sec]
GRB_SIGNIF:      12.48 [sigma]
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5926.26 SOD {01:38:46.26} UT,   115.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.66 237.10 261.59 243.83
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 50"}
SUN_DIST:        105.63 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.46d {+08h 57m 51s}  +21.79d {+21d 47' 11"}
MOON_DIST:        74.19 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.55, 22.08 [deg] galactic lon,lat of the burst
ECL_COORDS:       74.00, 68.67 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.19 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:40:34 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.330d {+22h 13m 19s} (J2000),
                 333.090d {+22h 12m 22s} (current),
                 333.767d {+22h 15m 04s} (1950)
GRB_DEC:         +83.566d {+83d 33' 59"} (J2000),
                 +83.690d {+83d 41' 23"} (current),
                 +83.317d {+83d 19' 01"} (1950)
GRB_DATE:        20608 TJD;   299 DOY;   24/10/25
GRB_TIME:        5810.57 SOD {01:36:50.57} UT
TRIGGER_INDEX:   271
GRB_PHI:         -31.66 [deg]
GRB_THETA:        39.32 [deg]
DELTA_TIME:      -18.00 [sec]
TRIGGER_DUR:     2.048 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.26 [sigma]
IMAGE_SIGNIF:    9.01 [sigma]
LC_URL:          sw01262165000msb.lc
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 51"}
SUN_DIST:        105.60 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.48d {+08h 57m 54s}  +21.78d {+21d 46' 57"}
MOON_DIST:        74.21 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       74.00, 68.70 [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 = 323.63,16.81 [deg].

GCN Circular #37859
E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), R. Gupta (NASA GSFC), J. A. Kennea (PSU), D. M. Palmer (LANL), T. M. Parsotan (GSFC) and B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team:
At 01:36:50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 241025A (trigger=1262165). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 333.330, +83.566 which is
```
   RA(J2000) = 22h 13m 19s
   Dec(J2000) = +83d 33' 59"
```
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 180 sec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 01:38:46.2 UT, 115.7 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 333.6488, 83.5739 which is equivalent to:
```
   RA(J2000)  = 22h 14m 35.71s
   Dec(J2000) = +83d 34' 26.0"
```
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This location is 131 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.
UVOT took a finding chart exposure of 150 seconds with the White filter starting 125 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	22:14:36.91 = 333.65379
  DEC(J2000) = +83:34:32.3  =  83.57565
```
with a 90%-confidence error radius of about 0.62 arc sec. This position is 6.6 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.56 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.249.
Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular #37860
The Fermi GBM team reports the detection of a likely LONG GRB
At 01:36:26 UT on 25 Oct 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241025A (trigger 751512991.890046 / 241025067).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 326.2, Dec = 80.3 (J2000 degrees, equivalent to J2000 21h 44m, 80d 17'), with a statistical uncertainty of 3.6 degrees.
The angle from the Fermi LAT boresight is 46.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_skymap_all_bn241025067.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_healpix_all_bn241025067.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241025067/quicklook/glg_lc_medres34_bn241025067.gif

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:49:27 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
POINT_ROLL:      302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6149.64 SOD {01:42:29.64} UT,   339.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.413
N_STARS:         27
X_OFFSET:        405 [pixels]
Y_OFFSET:        803 [pixels]
X_MAX:           1364 [pixels]
Y_MAX:           1762 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw01262165000msufc0339.fits
SUN_POSTN:       209.97d {+13h 59m 52s}  -12.22d {-12d 12' 58"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.55d {+08h 58m 13s}  +21.76d {+21d 45' 26"}
MOON_DIST:        74.24 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:49:41 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
POINT_ROLL:      302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6149.64 SOD {01:42:29.64} UT,   339.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.413
N_STARS:         27
X_OFFSET:        405 [pixels]
Y_OFFSET:        803 [pixels]
X_MAX:           1364 [pixels]
Y_MAX:           1762 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw01262165000msufc0339.fits
SUN_POSTN:       209.97d {+13h 59m 52s}  -12.22d {-12d 12' 59"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.56d {+08h 58m 14s}  +21.76d {+21d 45' 24"}
MOON_DIST:        74.24 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:50:37 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
ROLL:            302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6149.64 SOD {01:42:29.64} UT,   339.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     751513384
X_OFFSET:        725 [pixels]
Y_OFFSET:        1123 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1283
BINNING_INDEX:   1
IM_URL:          sw01262165000msuni0374.fits
SUN_POSTN:       209.97d {+13h 59m 52s}  -12.22d {-12d 13' 00"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.56d {+08h 58m 16s}  +21.75d {+21d 45' 14"}
MOON_DIST:        74.24 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [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:     Fri 25 Oct 24 01:50:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
ROLL:            302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6149.64 SOD {01:42:29.64} UT,   339.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     751513384
X_OFFSET:        725 [pixels]
Y_OFFSET:        1123 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1283
BINNING_INDEX:   1
IM_URL:          sw01262165000msuni0374.fits
SUN_POSTN:       209.97d {+13h 59m 52s}  -12.22d {-12d 13' 00"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.57d {+08h 58m 16s}  +21.75d {+21d 45' 13"}
MOON_DIST:        74.24 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [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:     Fri 25 Oct 24 01:56:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
POINT_ROLL:      302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6685.24 SOD {01:51:25.24} UT,   874.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.574
N_STARS:         190
X_OFFSET:        165 [pixels]
Y_OFFSET:        563 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           2002 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01262165000msufc0874.fits
SUN_POSTN:       209.97d {+13h 59m 53s}  -12.22d {-12d 13' 05"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.62d {+08h 58m 28s}  +21.74d {+21d 44' 12"}
MOON_DIST:        74.26 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       73.99, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:57:01 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
POINT_ROLL:      302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6685.24 SOD {01:51:25.24} UT,   874.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.574
N_STARS:         190
X_OFFSET:        165 [pixels]
Y_OFFSET:        563 [pixels]
X_MAX:           1604 [pixels]
Y_MAX:           2002 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01262165000msufc0874.fits
SUN_POSTN:       209.97d {+13h 59m 53s}  -12.22d {-12d 13' 05"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.62d {+08h 58m 29s}  +21.74d {+21d 44' 09"}
MOON_DIST:        74.26 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       73.99, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:58:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
ROLL:            302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6685.24 SOD {01:51:25.24} UT,   874.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     751513919
X_OFFSET:        724 [pixels]
Y_OFFSET:        1122 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       884
Y_GRB_POS:       1282
BINNING_INDEX:   1
IM_URL:          sw01262165000msuni0909.fits
SUN_POSTN:       209.97d {+13h 59m 53s}  -12.22d {-12d 13' 06"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.63d {+08h 58m 31s}  +21.73d {+21d 43' 58"}
MOON_DIST:        74.27 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       73.99, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:57:22 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.6544d {+22h 14m 37.05s} (J2000),
                 333.4203d {+22h 13m 40.87s} (current),
                 334.0814d {+22h 16m 19.53s} (1950)
GRB_DEC:         +83.5759d {+83d 34' 33.2"} (J2000),
                 +83.6996d {+83d 41' 58.4"} (current),
                 +83.3259d {+83d 19' 33.3"} (1950)
GRB_ERROR:       1.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6255.00 SOD {01:44:15.00} UT,   444.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       209.97d {+13h 59m 53s}  -12.22d {-12d 13' 05"}
SUN_DIST:        105.63 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.62d {+08h 58m 30s}  +21.73d {+21d 44' 05"}
MOON_DIST:        74.24 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.55, 22.08 [deg] galactic lon,lat of the burst
ECL_COORDS:       74.00, 68.67 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:58:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.338d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.566d {+83d 33' 57"} (J2000)
ROLL:            302.032d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  6685.24 SOD {01:51:25.24} UT,   874.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     751513919
X_OFFSET:        724 [pixels]
Y_OFFSET:        1122 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       884
Y_GRB_POS:       1282
BINNING_INDEX:   1
IM_URL:          sw01262165000msuni0909.fits
SUN_POSTN:       209.97d {+13h 59m 53s}  -12.22d {-12d 13' 06"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.63d {+08h 58m 32s}  +21.73d {+21d 43' 56"}
MOON_DIST:        74.27 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       73.99, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:41:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.339d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.567d {+83d 34' 02"} (J2000)
POINT_ROLL:      302.033d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5936.26 SOD {01:38:56.26} UT,   125.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.501
N_STARS:         58
X_OFFSET:        480 [pixels]
Y_OFFSET:        552 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1511 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01262165000msufc0125.fits
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 52"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.49d {+08h 57m 57s}  +21.78d {+21d 46' 45"}
MOON_DIST:        74.21 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:43:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.339d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.567d {+83d 34' 02"} (J2000)
ROLL:            302.033d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5936.26 SOD {01:38:56.26} UT,   125.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     751513170
X_OFFSET:        725 [pixels]
Y_OFFSET:        1123 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1283
BINNING_INDEX:   1
IM_URL:          sw01262165000msuni0160.fits
SUN_POSTN:       209.96d {+13h 59m 51s}  -12.21d {-12d 12' 53"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.50d {+08h 58m 00s}  +21.78d {+21d 46' 31"}
MOON_DIST:        74.22 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [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:     Fri 25 Oct 24 01:43:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.339d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.567d {+83d 34' 02"} (J2000)
ROLL:            302.033d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5936.26 SOD {01:38:56.26} UT,   125.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     751513170
X_OFFSET:        725 [pixels]
Y_OFFSET:        1123 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1283
BINNING_INDEX:   1
IM_URL:          sw01262165000msuni0160.fits
SUN_POSTN:       209.96d {+13h 59m 51s}  -12.22d {-12d 12' 53"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.50d {+08h 58m 00s}  +21.77d {+21d 46' 30"}
MOON_DIST:        74.22 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [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:     Fri 25 Oct 24 01:45:14 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     1262165,   Seg_Num: 0
GRB_RA:          333.6537d {+22h 14m 36.88s} (J2000),
                 333.4196d {+22h 13m 40.71s} (current),
                 334.0807d {+22h 16m 19.36s} (1950)
GRB_DEC:         +83.5756d {+83d 34' 32.1"} (J2000),
                 +83.6993d {+83d 41' 57.4"} (current),
                 +83.3256d {+83d 19' 32.2"} (1950)
GRB_ERROR:       0.6 [arcsec radius, statistical only]
GRB_MAG:         17.55 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5933.00 SOD {01:38:53.00} UT,   122.4 [sec] since BAT Trigger Time
SUN_POSTN:       209.96d {+13h 59m 51s}  -12.22d {-12d 12' 55"}
SUN_DIST:        105.63 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.52d {+08h 58m 04s}  +21.77d {+21d 46' 09"}
MOON_DIST:        74.20 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.55, 22.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       74.00, 68.67 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The UVOT position is 6.1 arcsec from the XRT position.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Oct 24 01:41:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1262165,   Seg_Num: 0
POINT_RA:        333.339d {+22h 13m 21s} (J2000)
POINT_DEC:       +83.567d {+83d 34' 02"} (J2000)
POINT_ROLL:      302.033d
IMG_START_DATE:  20608 TJD;   299 DOY;   24/10/25
IMG_START_TIME:  5936.26 SOD {01:38:56.26} UT,   125.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.501
N_STARS:         58
X_OFFSET:        480 [pixels]
Y_OFFSET:        552 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1511 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01262165000msufc0125.fits
SUN_POSTN:       209.96d {+13h 59m 50s}  -12.21d {-12d 12' 52"}
SUN_DIST:        105.61 [deg]   Sun_angle= -8.2 [hr] (East of Sun)
MOON_POSTN:      134.49d {+08h 57m 57s}  +21.78d {+21d 46' 43"}
MOON_DIST:        74.21 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:      118.52, 22.10 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       74.00, 68.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN Circular #37862
S.Q. Jiang (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), Z.P. Zhu, S.Y. Fu, J. An, X. Liu, Z. Fan, W.X. Li, N.C. Sun, Y.N. Wang, D. Xu (NAOC) report on behalf of a large collaboration:
We observed the field of GRB 241025A detected by Swift (Ambrosi et al., GCN 37859), EP (EP241025a, ID: 01709111485), Fermi (Fermi GBM team, GCN 37860), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Fresno, California, US. Observations started at 02:24:10.976 UTC on 2024-10-25, i.e., 47.34 mins after the Swift trigger, and a series of 200 s frames were obtained in R-band.
The optical afterglow by Swift/UVOT (Ambrosi et al., GCN 37859) is clearly detected in our individual as well as stacked images. Its brightness is varying and has R = 19.68 +/- 0.12 mag in the first image at a median time 0.817 hr after the Swift trigger, calibrated with PanSTARRS and not corrected for Galactic extinction.
GCN Circular #37863
SVOM/GRM team: Chen-Wei Wang, Shi-Jie Zheng, Yong-Wei Dong, Jiang-Tao Liu, = Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye L= i, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zh= ang, Wen-Jun Tan, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie = Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen= -Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, = Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao, Chao Zheng (IHEP), Maria-Grazi= a Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Ta= is Maiolino (LUPM), Fr=C3=A9d=C3=A9ric Piron (LUPM), St=C3=A9phane Schanne = (CEA), Jingwei Wang (IAP), JeanLuc Att=C3=A9ia (IRAP)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (I= HEP), St=C3=A9phane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Fr= =C3=A9d=C3=A9ric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), = Andrea Goldwurm (APC), Diego G=C3=B6tz (CEA), Xu-Hui Han (NAOC), Cyril Lac= haud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Par= is), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong = (IHEP), Bing Zhang (UNLV)
report on behalf of the SVOM team:
During the commissioning phase, the SVOM/GRM was triggered in-flight by GRB= 241025A at 2024-10-25T01:36:40 UT (T0), which was also observed by Fermi/G= BM (Fermi GBM Team, GCN 37860), Swift/BAT (E. Ambrosi et al., GCN 37859).
The real-time alert data and light curves of SVOM/GRM were downlinked to th= e ground through the VHF system with low latency. The GRM light curve shows= that this burst consists of multiple pulses with a T90 of 37.6 +1.7/-1.1 s= .
The GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb241025A.png
The telecommand for the ToO observation related to this burst has been succ= essfully uploaded to SVOM.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission l= ed by the Chinese National Space Administration (CNSA, China), National Cen= ter for Space Studies (CNES, France) and the Chinese Academy of Sciences (C= AS, China), which is dedicated to observing gamma-ray bursts and other tran= sient phenomena in the energetic universe. GRM is developed by the Institut= e of High Energy Physics (IHEP) of CAS.
The SVOM point of contact for this burst is: Chen-Wei Wang (IHEP)(cwwang@ih= ep.ac.cn)
GCN Circular #37864
D. Y. Li (NAO, CAS), Z. Y. Liu, M. Q. Huang (USTC), J. Q. Peng (IHEP, CAS), C. C. Jin (NAO, CAS) report on behalf of the Eintein Probe team:
We report on the detection of an X-ray transient detected by EP-WXT, EP241025a, which triggered the on-board processing unit at 2024-10-25T01:36:45 (UTC) (trigger ID: 01709111485). The trigger flux is estimated to be around 2e-10 erg/s/cm2 in 0.5-4 keV, assuming a spectral shape of absorbed power-law with a photon index of 2. An autonomous observation on the X-ray transient was performed by the EP-FXT about 3 minutes later, which also detected an X-ray source at R.A. = 333.6408 deg, DEC = 83.5772 deg (J2000) with an uncertainty of about 10 arcsecs (radius, 90% C.L. statistical and systematic), consistent with the position of the WXT transient within the uncertainties. The source flux is estimated to be around 5e-11 erg/s/cm2. We note that the trigger time and position of this X-ray transient are consistent with that of GRB 241025A (Swift GCN 37859, Fermi GBM GCN 37860, SVOM/GRM GCN 37863).
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).
GCN Circular #37865
Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa Be= cerra (UTOV), Simone Dichiara (PSU), Tzveti Dimitrova (ASU), Oc=C3=A9lotl L= =C3=B3pez (UNAM), Camila Angulo (UNAM), Alexander Kutyrev (GSFC/UMD), Willi= am H. Lee (UNAM) and Eleonora Troja (UTOV) report:
We observed the field of the GRB 241025A detected by Swift (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860) with the DDOTI/OAN wide-field imager at the Observatorio Astron=C3=B3mico Nacional on Sierra San Pedro M=C3=A1r= tir (http://ddoti.astroscu.unam.mx) on 2024-10-25 from 02:28 to 02:43 UTC, 51min to 1.1hrs after the event, obtaining a total of 11 minutes of exposure in the w filter.
We detect a source at 22:14:36.94 +83:34:31.9, consistent with the position of the UVOT afterglow (Ambrosi et al., GCN 37859 ; Jiang et al, GCN 37862), with the following magnitude and 10-sigma uncertainty: w = 20.20 +/- 0.19 mag.
Our photometry is calibrated against the APASS catalog, on an approximate AB system, and is not corrected for Galactic extinction in the direction of the GRB.
We thank the DDOTI technical team and the staff of the Observatorio Astron= =C3=B3mico Nacional.
GCN Circular #37866
D. Xu (NAOC), L. Izzo (INAF/OACn and DARK/NBI), Z.P. Zhu, S.Y. Fu (NAOC), N. Koivisto (NOT), T. B=C3=A4cker, M. Varding, R. Tuomainen, A. Willstedt Justel, T. Gobold (UH) report on behalf of a larger collaboration:
We have observed the optical counterpart (Ambrosi et al., GCN#37859; Jiang et al., GCN#37862) of GRB 241025A (Ambrosi et al., GCN#37859; Fermi GBM team, GCN#37860; Wang et al., GCN#37863; Li et al., GCN 37864), using the Nordic Optical Telescope (NOT) equipped with the ALFOSC spectrograph. Grism #4 was used, covering the wavelength range 3650-9500 AA. Four spectra of 1200 s exposure time each have been obtained, with the first sequence starting at 02:07:32 UT on 2024-10-25, i.e., 0.51 hr after the Swift trigger.
Preliminary analysis of the data reveals a bright continuum in the red part of the spectrum, with a clear break around 6310 AA, which we interpret as due to Lyman alpha. We also identify the Lyman limit, the Lyman forest, and several metal absorption features, interpreted as due to Si II, Si IV, O I, C II, C IV, Fe II and Al II, all at a common redshift of z = 4.20.
GCN Circular #37868
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 947 s of XRT Photon Counting mode data and 1 UVOT images for GRB 241025A, 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 = 333.65769, +83.57588 which is equivalent to:
```
RA (J2000): 22h 14m 37.85s
Dec (J2000): +83d 34' 33.2"
```
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 #37871
SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, C. Wu, L. P. Xin, X. H. Ha= n, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. De= ng, L. Lan, X. M. Lu, R. S. Zhang, (NAOC), J. Zhang, L. J. Dan, G. Y. Zou,= C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO), S. L. Xiong(IHEP)= =20
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (I= HEP), St=C3=A9phane Basa (LAM), Olivier Godet (IRAP), Arnaud Claret (CEA), = Zi-Gao Dai (USTC), Fr=C3=A9d=C3=A9ric Daigne (IAP), Jin-Song Deng (NAOC), A= ndrea Goldwurm (APC), Diego G=C3=B6tz (CEA), Xu-Hui Han (NAOC), Cyril Lacha= ud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris= ), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV)
report on behalf of the SVOM team:
VT started to observe the field of GRB 241025A (Ambrosi et al., GCN#37859; = Fermi GBM team, GCN#37860; Wang et al., GCN#37863; Li et al., GCN 37864)via= ToO observations started at 2024-10-25T04:03:55 UT, about 2.45 hours after= the burst. The VT conducted observations simultaneously in two channels: V= T_B (400nm-650nm) and VT_R (650nm-1000nm).
The counterpart (Ambrosi et al., GCN#37859; Jiang et al., GCN#37862, Pereyr= a et al., GCN#37865; Xu et al., GCN#37866) was clearly detected in both ba= nds with VT_B=3D20.8+/-0.2 mag and VT_R=3D19.07+/-0.07 mag at 2.45 hours po= st the burst.=20
More observations are on-going.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission l= ed by the Chinese National Space Administration (CNSA, China), National Cen= ter for Space Studies (CNES, France) and the Chinese Academy of Sciences (C= AS, China), which is dedicated to observing gamma-ray bursts and other tran= sient phenomena in the energetic universe. VT was jointly developed by Xi'a= n Institute of Optics and Precision Mechanics (XIOPM), CAS and National ast= ronomical observatories (NAOC),CAS.
GCN Circular #37872
D. Y. Li (NAO, CAS), Z. Y. Liu, M. Q. Huang (USTC), J. Q. Peng (IHEP, CAS), C. C. Jin (NAO, CAS) report on behalf of the Einstein Probe team:
The preliminary analysis of the telemetry EP-WXT data shows that the bright transient EP241025a (GRB 241025A, Swift GCN 37859, Fermi GBM GCN 37860, SVOM/GRM GCN 37863, EP GCN 37864) began at (T0) 2024-10-25T01:35:29 (UTC), and lasted for around 300 seconds, with the peak flux in 0.5-4.0 keV to be around 1e-8 erg/s/cm2. The EP-FXT autonomous observation began at T0+3min and caught the latter half of the bright transient, followed by lasting fainter emission. The ground calculated EP-FXT position is RA=333.6550 deg, DEC=83.5750 deg (J2000), with an uncertainty of 10 arcsecs (radius, 90% C.L. statistical and systematic), which is consistent with the enhanced XRT position (GCN 37868). The averaged EP-FXT spectrum can be fitted with an absorbed powerlaw, with a photon index of (1.41 +/- 0.09), and an absorption of NH= (2.2 +/- 0.4) e21 cm^(-2). The derived average unabsorbed flux in 0.5-4.0 keV is (1.6 +/- 0.7) e-10 erg/s/cm2. All the errors of the parameters quoted are at 90% C.L.
Please note that the temporal and spectral analyses presented above are preliminary. The final results will be presented in future publications. EP-FXT will also keep monitoring this transient in the following days.
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).
GCN Circular #37873
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 GRB 241025A ( E. Ambrosi et al., GCN 37859) errorbox 33497 sec after notice time and 33548 sec after trigger time at 2024-10-25 10:55:58 UT, with upper limit up to 17.8 mag. Observations started at twilight. The observations began at zenith distance = 34 deg. The sun altitude is -10.3 deg.
The galactic latitude b = 22 deg., longitude l = 119 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2648532
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   33563 |        MASTER-Tunka |   C |    30 | 17.7 |        
   33606 |        MASTER-Tunka |   C |    30 | 17.7 |        
   33650 |        MASTER-Tunka |   C |    30 | 17.8 |        
   33693 |        MASTER-Tunka |   C |    30 | 17.8 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #37874
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) started inspect of the Fermi GRB 241025A ( Fermi GBM team, GCN 37860) errorbox 33528 sec after notice time and 33571 sec after trigger time at 2024-10-25 10:55:58 UT, with upper limit up to 18.6 mag. Observations started at twilight. The observations began at zenith distance = 34 deg. The sun altitude is -10.3 deg.
The galactic latitude b = 20 deg., longitude l = 116 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2648590
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   33587 | 2024-10-25 10:55:58 |        MASTER-Tunka | (22h 21m 51.83s , +83d 24m 29.9s) |   C |    30 | 17.7 |        
   33630 | 2024-10-25 10:56:41 |        MASTER-Tunka | (22h 21m 57.07s , +83d 23m 31.1s) |   C |    30 | 17.7 |        
   33674 | 2024-10-25 10:57:25 |        MASTER-Tunka | (22h 21m 50.77s , +83d 22m 33.0s) |   C |    30 | 17.8 |        
   33716 | 2024-10-25 10:58:08 |        MASTER-Tunka | (22h 21m 56.24s , +83d 22m 37.1s) |   C |    30 | 17.8 |        
   33860 | 2024-10-25 11:00:31 |        MASTER-Tunka | (22h 21m 59.88s , +83d 22m 43.0s) |   C |    30 | 18.1 |        
   33919 | 2024-10-25 11:01:27 |        MASTER-Tunka | (22h 22m 05.43s , +83d 24m 20.8s) |   C |    36 | 18.3 |        
   34038 | 2024-10-25 11:03:26 |        MASTER-Tunka | (22h 21m 56.61s , +83d 24m 43.0s) |   C |    36 | 18.6 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #37882
I. Abdi (AUS), E. de Bruin (UMN), C. Andrade (UMN), T.Hussenot (IJCLAB), M. Masek(FZU), S. Antier (OCA), S. Karpov (FZU), M. Coughlin (UMN), I. Tosta e Melo (UniCT-DFA), P. Hello, N. Leroy (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), M. Tanasan (NARIT), K. Noysena (NARIT), D.Turpin (CEA-Saclay/Irfu), M. Freeberg (KNC), D. St-Gelais (KNC) on behalf of the GRANDMA and Kilonova-Catcher collaborations:
We observed the Swift/UVOT localisation of GRB 241025A, detected by Swift/BAT (GCN 37859) with the GRANDMA network and its citizen science project Kilonova-catcher (KNC). Our observations started 70 min after the trigger.
We detect at the Swift/UVOT coordinates the afterglow already observed by TRT (GCN 37862) DDOTI (GCN 37865) and SVOM/VT (GCN 37871), and we obtain the following magnitudes and 5-sigma upperlimits:
```
| Tstart (UTC)  | Telescope | Exposure | Filter | Magnitude (Vega) |
	 	 	 	
| 2024-10-25T02:46:16 | KNC-iT11 | 4x180s | R | >18.5 (U.L) |
| 2024-10-25T03:28:43 | KNC-iT21 | 10x180s | V | >18.5 (U.L) |
| 2024-10-25T04:04:36 | KNC-iT21 | 10x180s | R | 19.29 +- 0.15 |
| 2024-10-25T04:58:39 | TRT-SRO | 5x300s | R | 19.66 +- 0.05  |
| 2024-10-25T06:05:10 | KNC-iT11 | 20x180s | R | 19.97 +- 0.22 |
| 2024-10-25T06:35:00 | TRT-SRO | 5x300s | I | 18.90 +- 0.08 |
| 2024-10-25T07:25:25 | TRT-SRO | 5x200s | B | > 21.4 (U.L) |
| 2024-10-25T07:50:17 | TRT-SRO | 5x200s | V | >21.1 (U.L) |
| 2024-10-25T08:04:33 | TRT-SRO | 5x200s | R | 20.23 +- 0.08 |
| 2024-10-25T08:25:49 | TRT-SRO | 5x200s | I | 19.08 +- 0.17 |
```
The V-band image of TRT-SRO contains a marginal 4-sigma detection at V=21.11+-0.23, just under the V>21.1 5-sigma upperlimit.
TRT-SRO images were calibrated using the PanSTARRS catalog. KNC images were calibrated using the Gaia DR3 Synphot catalog.
All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). We use the SkyPortal application (skyportal.io) to monitor our observational campaign.
GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).
GCN Circular #37886
Matt Godwin (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 01:36:26.89 UT on 25 October 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241025A (trigger 751512991/241025067). which was also detected by Swift BAT (V. D'Elia et al. 2024, GCN 37859) and Einstein Probe (D.Y. Li et al. 2024, GCN 37864) The Fermi GBM on-ground location is consistent with the Swift BAT position.
The angle from the Fermi LAT boresight is 47 degrees.
The GBM light curve consists of multiple close peaks with a duration (T90) of about 124 s (50-300 keV). The time-averaged spectrum from T0+2.3 to T0+125.2 s is best fit by a Band function. The power law index is -0.93 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 235 +/- 22 keV.
The event fluence (10-1000 keV) in this time interval is (1.46 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+46 s in the 10-1000 keV band is 3 +/- 0.2 ph/s/cm^2.
A power law function with an exponential high-energy cutoff fits the spectrum equally well. The power law index is -0.92 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 232 +/- 18 keV.
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 #37888
K.L. Page (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), S. Dichiara (PSU), J.A. Kennea (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester) and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 241025A, from 109 s to 80.1 ks after the BAT trigger. The data comprise 321 s in Windowed Timing (WT) mode (the first 4 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode.
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=8.0 (+0.0, -0.5). At T+126 s the decay flattens to an alpha of 3.15 (+0.20, -0.21) before breaking again at T+221 s to a final decay with index alpha=1.071 (+0.026, -0.025).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.77 (+/-0.05). The best-fitting absorption column is 3.6 (+/-1.1) x 10^22 cm^-2, at a redshift of 4.2, in addition to the Galactic value of 1.2 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.68 (+/-0.12) and a best-fitting absorption column of 2.4 (+2.4, -2.1) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.3 x 10^-11 (5.1 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Galactic foreground: 1.2 x 10^21 cm^-2
Intrinsic column:    2.4 (+2.4, -2.1) x 10^22 cm^-2 at z=4.2
Photon index:	     1.68 (+/-0.12)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01262165.
This circular is an official product of the Swift-XRT team.
GCN Circular #37889
Alan M. Watson (UNAM), Margarita Pereyra (UNAM), St=C3=A9phane Basa (UAR Pytheas), William H. Lee (UNAM), S. Antier (OCA), Jean-Luc Atteia (IRAP), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), J.-G. Ducoin (CPPM), Francis Fortin (IRAP), Simona Lombardo (LAM), and Francesco Magnani (CPPM) report:
We imaged the field of GRB 241025A detected by Swift/BAT, Fermi/GBM, and SVOM/GRM (GCN Circ. 37859, 37860, 37863) during the commissioning of the COLIBR=C3=8D (SVOM/F-GFT) telescope at the Observatorio Astron=C3=B3mico Na= cional on the Sierra de San Pedro M=C3=A1rtir in Mexico.
The observations started 39 minutes after the GRB trigger. We observed with the engineering test camera in a red filter that approximates SDSS r. The data were reduced using custom software and then analysed and calibrated against the PS1 catalog using the STDWeb service.
In 1980 seconds of exposure from 2024-10-25 02:15 to 03:00, we detect the optical counterpart with:
r = 19.64 +/- 0.04
This magnitude is consistent with other optical observations (GCN Circ. 37862, 37865, 37871, and 37882).
We warmly thank the COLIBRI engineering team and the staff of the Observatorio Astron=C3=B3mico Nacional on the Sierra de San Pedro M=C3=A1rt= ir.
GCN Circular #37890
T. Mohan, V. Swain, R. Kumar, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:
We observed the field of GRB 241025A observed by SVOM/GRM (GCN 37863), Fermi/GBM (Fermi GBM Team, GCN 37860), Swift/BAT (E. Ambrosi et al., GCN 37859) with 0.7m GROWTH-India Telescope (GIT). We started the observation at 2024-10-25 15:50:58, i.e., 14.23 hours after the Swift-BAT trigger. We obtained multiple exposures of 360 seconds in the i' filter. In our stacked images, we detected the optical afterglow at the coordinates reported by Swift UVOT. The photometry results follow as:
```
---------------------------------------------------------------------------------
| MJD (mid) | Filter | Total Exposure (s) | Magnitude (AB) | 
| -----------------|------- | ------------------ | -------------- |
| 60608.6728935|   i'   |      6x360         | 20.3 +/- 0.08 |

---------------------------------------------------------------------------------
```
Above optical afterglow is also observed by Jiang et al., (GCN 37862), Pereyra et al., (GCN 37865), SVOM/VT (GCN 37871), Abdi et al., (GCN 37882), Watson et al. (GCN 37889).
The measurement is 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 #37891
J. Vinko, K. Sarneczky, Zs. Bora, A. Horti-David, R. Konyves-Toth, L. Kriskovics, A. Pal, R. Szakats (Konkoly Observatory, Hungary)
We report detection and photometry of the optical afterglow of GRB 241025A (Ambrosi et al., GCN 37859; Fermi GBM team GCN 37860; Wang et al. GCN 37863) taken with the RC80 robotic telescope at Piszkesteto Station of Konkoly Observatory, Hungary. The observations started on 2024-10-25 16:48:09.79 UT, 15.19 hours after the trigger. 7 sets of 300 sec frames were collected through. Sloan r'- and i' bands.
The optical afterglow (Jiang et al. GCN 37862; Pereyra et al. GCN 37865; SVOM/VT team GCN 37871; Abdi et al. GCN 37882; Watson et al. GCN 37889; Mohan et al. GCN 37890) was detected on the stacked frames with the following magnitudes, calibrated via nearby PS1 stars:
```
Date       UT-middle   t-T0(days) Exp(s) r'(AB)       i'(AB)
2024-10-25 17:18:57.70 0.65425    7x300  22.04 (0.35) 20.07 (0.17)
```
The magnitudes above are not corrected for galactic extinction.
GCN Circular #37893
Anshika Gupta, Amit K. Ror, Sneh Lata, Dorothy Museo, Kuntal Misra and Shashi B. Pandey (ARIES) report:
We observed the field of GRB 241025A detected by Swift-BAT (GCN 37859) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located at the Devasthal Observatory of the Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2024-10-25 at 14:13:20 UT, i.e., ~ 12.60 hours after the BAT trigger. We have taken multiple frames with an exposure time of 300 s in the R filter. We stacked the images after the alignment. We clearly detected optical afterglow in our stacked image within the error box of the enhanced Swift-XRT position by Goad et al. 2024 (GCN 37868). We obtained the following preliminary magnitude in the stacked image:
Date Start_UT T_start-T0 (hour) Filter Exp time (s) magnitude
===============================================================
2024-10-25 14:13:20 ~12.60 R 300*12 20.45 +- 0.05
Our detection is consistent with Jiang et al. 2024 (GCN 37862); Pereyra et al. 2024 (GCN 37865); Xu et al. 2024 (GCN 37866); SVOM Team(GCN 37871); Abdi et al. 2024 (GCN 37882); Watson et al. 2024(GCN 37889); Mohan et al. 2024(GCN 37890), and Vinko et al. 2024 (GCN 37891).
The magnitude is not corrected for the Galactic extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalog. This circular may be cited.
GCN Circular #37912
N. Pankov (HSE), E. Klunko (ISTP), A. Pozanenko (IKI), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of Swift GRB 241025A (Ambrosi et al. GCN 37859) with AZT-33IK telescope of Mondy observatory in R-filter on 2024-10-26 starting (UT) 17:13:51. We detect optical afterglow (Ambrosi et al., GCN 37859; Jiang et al., GCN 37862; Pereyra et al., GCN 37865; Xu et al., GCN 37866; SVOM/VT team, GCN 37871; Abdi et al., GCN 37882; Watson et al., GCN 37889; Mohan et al., GCN 37890; Vinko et al., GCN 37891; Gupta et al., GCN 37893). Preliminary photometry of first images is the following
Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s)
2024-10-26 17:13:51 1.66876 26x120 R 21.7 0.2 22.8
The photometry is based on nearby USNO-B1.0 stars.
GCN Circular #37914
A. S. Moskvitin and O. I. Spiridonova (SAO RAS), report on behalf of the GRB follow-up team.
We observed the field of Swift GRB 241025A (Ambrosi et al. GCN 37859) with the 1-m telescope of SAO RAS equipped with the CCD-photometer. We obtained 12 x 300 sec. images in Rc band on October 26, 19:28:34--20:36:33 UT (t_mid - T0 = 1.7679 days)
The OT (Ambrosi et al., GCN 37859; Jiang et al., GCN 37862; Pereyra et al., GCN 37865; Xu et al., GCN 37866; SVOM/VT team, GCN 37871; Abdi et al., GCN 37882; Watson et al., GCN 37889; Mohan et al., GCN 37890; Vinko et al., GCN 37891; Gupta et al., GCN 37893; Pankov et al., GCN 37912) is clearly detected in our stacked frame with the brightness of R = 22.17 +/- 0.09.
This preliminary photometry is based on nearby USNO-B1.0 stars and not corrected for the Galaxy extinction.
GCN Circular #37919
N. J. Klingler (GSFC/UMBC/CRESTII) and E. Ambrosi (INAF-IASFPA) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 241025A 126 s after the BAT trigger (Ambrosi et al., GCN Circ. 37859). A source consistent with the XRT position (Evans et al.; GCN Circ. 37868) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
    RA  (J2000) =  22:14:36.83 = 333.65346 (deg.)
    Dec (J2000) = +83:34:32.2  =  83.57562 (deg.)
```
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              126          275          147         17.55 +/- 0.04
v                  671         5229          274        >19.4
b                  595         1347           78        >20.2
u                  339         1322          304        >20.5
w1                 722         5483          101        >21.0
m2                5234         5434          197        >20.2
w2                1030         1050           19        >19.5
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.249 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #37923
A. S. Moskvitin and O. I. Spiridonova (SAO RAS), report on behalf of the GRB follow-up team.
We observed the field of GRB 241025A (Ambrosi et al. GCN 37859; The Fermi GBM team, GCN 37860; Godwin, GCN 37886) with the 1-m telescope of SAO RAS equipped with the CCD-photometer. We obtained 12 x 300 sec. images in Rc band on October 27, 19:33:44--20:42:52 UT (t_mid - T0 = 2.7719 days).
The OT (Ambrosi et al., GCN 37859; Jiang et al., GCN 37862; Pereyra et al., GCN 37865; Xu et al., GCN 37866; SVOM/VT team, GCN 37871; Abdi et al., GCN 37882; Watson et al., GCN 37889; Mohan et al., GCN 37890; Vinko et al., GCN 37891; Gupta et al., GCN 37893; Pankov et al., GCN 37912; Moskvitin and Spiridonova, GCN 37914; Klingler and Ambrosi, GCN 37919) is clearly detected in our stacked frame with the brightness of R = 22.98 +/- 0.11 (R_lim = 24.1).
This preliminary photometry is based on nearby USNO-B1.0 stars and not corrected for the Galaxy extinction.
GCN Circular #37926
X. F. Wang (THU), A. Iskandar=EF=BC=88XAO), J. L. Liu (THU)=EF=BC=8CL. T. W= ang (XAO), J. Mo (THU), Y.S. Yan (THU), S. Antier (OCA)=EF=BC=8Cand W. X. L= i (NAOC) report the optical detections of the afterglow of GRB 241025A/EP24= 1025a (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860; Jiang et al., = GCN 37862; Wang et al., GCN 37863; Li et al., GCN 37864; Pereyra et al., GC= N 37865; Xu et al., GCN 37866; Lipunov et al., GCN 37873; Abdi et al., GCN = 37882).
We obtained 300sx9 (~12.8 hrs after the burst) and 100sx30 (~13.3 hrs after= the burst) r-band images with the 80~cm Tsinghua-Nanshan Optical Telescope= (TNOT) located at Nanshan Station of Xinjiang Astronomy Observatory. The a= fterglow is clearly detected on the stacked images, with the following magn= itudes:
```
r =3D 21.12 +- 0.08 mag (MJD =3D 60608.60)
r =3D 21.17 +- 0.10 mag (MJD =3D 60608.62)
```
The above photometric results are calibrated using the field stars from the Pan-STARRS1 catalog and are not corrected for the Galactic extinction.
GCN Circular #37927
D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long-duration GRB 241025A (Swift-BAT detection: Ambrosi et al., GCN 37859; Fermi-GBM detection: Fermi GBM team, GCN 37860; Godwin, GCN 37886; SVOM-GRM detection: Wang et al., GCN 37863; EP-WXT detection: Li et al., GCN 37864) was detected by Konus-Wind (KW) in the waiting mode at T0~5786 s UT (01:36:26).
A Bayesian block analysis of the KW waiting mode data in the 20-300 keV band reveals a >20 sigma count rate increase in the interval from T0-13 s to ~T0+128 s.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241025A/
The total burst fluence is 1.58(-0.14,+0.14)x10^-5 erg/cm^2, and the 2.944 s peak energy flux, measured from T0+0.143 s, is 4.5(-0.5,+0.5)x10^-7 erg/cm^2. (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst, measured from T0-13 s to T0+128 s, can be described by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.85(-0.13,+0.15) and Ep = 238(-33,+38) keV.
The spectrum near the peak count rate, measured from T0+12 s to T0+30 s, can be described by a CPL model with alpha = -0.04(-0.17,+0.20) and Ep = 261(-23,+24) keV.
Assuming the redshift z=4.20 (Xu et al., GCN 37866) and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso is (5.5+/-0.5)x10^53 erg, the peak luminosity L_iso is (8.2+/-0.9)x10^52 erg/s, the rest-frame peak energy of the time-averaged spectrum Ep,i,z is (1238+/-182) keV, and the spectrum near the maximum count rate Ep,p,z is (1357+/-120) keV.
With the obtained estimates, GRB 241025A is inside 68% prediction bands for 'Amati' and 'Yonetoku' relations for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021), see http://www.ioffe.ru/LEA/GRBs/GRB241025A/GRB241025A_rest_frame.pdf
All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary.
GCN Circular #37964
R. Ruffini, L. Becerra, C.L. Bianco, M. Della Valle, Liang Li, G.J. Mathews, M.T. Mirtorabi, R. Moradi, F. Rastegar Nia, J.A. Rueda and Y. Wang We are comparing and contrasting the seven episodes of BdHN I observed in GRB 241025A with Eiso = 5.5 x 10^53 erg (GCN 37927) and GRB 220101A with Eiso = 3.7 x 10^54 erg (GCN 31365). Both are highly energetic and located at a redshift greater than 4 (GCN 37866, GCN 31353), which allows a zoom-in investigation due to cosmological expansion. By examining the onset of black hole formation and the ultra-relativistic prompt emission (UPE), we gain insight into the rotational dynamics within these systems. This investigation requires additional observational data, particularly optical emission measurements from the newly born pulsar and extended X-ray afterglow data up to more than 10^6 seconds. Concurrent monitoring by Fermi-LAT will be crucial for capturing high-energy emissions, while the already performed Fermi-GBM observations enable the identification of the jetted emission. On this basis, the energy extraction process from a newly formed black hole will be determine.
GCN Circular #38114
A. Rossi, E. Maiorano (INAF/OAS), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Melandri, D. Paris, and E. Marini (INAF-OAR), report on behalf of a larger collaboration:
We observed the optical counterpart of GRB 241025A (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860; Wang et al., GCN 37863; Li et al., GCN 37864) with the LBC camera mounted on LBT (Mt. Graham, AZ, USA) in the r', i', and z' bands with approximate midtime 04:54:00 UT on 2024-10-28, or 3.14 days after the burst. Observations were performed under an average seeing of ~1.2" but with a few passing cirrus.
The optical afterglow (Ambrosi et al., GCN 37859; Jiang et al., GCN 37862; Pereyra et al., GCN 37865; Xu et al., GCN 37866; SVOM/VT team, GCN 37871; Abdi et al., GCN 37882; Watson et al., GCN 37889; Mohan et al., GCN 37890; Vinko et al., GCN 37891; Gupta et al., GCN 37893; Pankov et al., GCN 37912; Moskvitin and Spiridonova, GCN 37914 and 37923; Klingler and Ambrosi, GCN 37919; Wang et al., GCN 37926) is well detected in all bands. We measure a preliminary AB magnitude of
r' = 23.6+-0.1,
calibrated against Pan-STARRS field stars, and not corrected for the foreground Galactic extinction.
We acknowledge excellent support from the LBTO and LBT-INAF staff, particularly O. Kuhn and R. Ansaldi.
GCN Circular #38130
S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.), N. Omodei (Stanford Univ.), O. S. Salafia (INAF-OAB)
At 19:11:50 UT on 2024 Oct 25 (T_mid = 0.76 days post-burst) the Karl G. Jansky VLA observed the field of GRB 241025A (Ambrosi et al., GCN 37859; Fermi GBM team, GCN 37860; SVOM team, GCN 37863; Li et al., GCN 37864; Svinkin et al., GCN 37927) in three bands, with central frequencies of 6, 10 and 15 GHz.
The standard 3C286 was used as bandpass and flux density calibrator, while J2344+8226 was used as phase calibrator.
From a preliminary analysis, an unresolved radio source is clearly detected at a position (J2000):
```
RA: 22:14:36.859 +- 0.001
Dec: +83:34:32.27 +- 0.02
```
consistent with the optical (Ambrosi et al., GCN 37859; Klingler et al., GCN 37919) and X-ray (Goad et al., GCN 37868) position of the transient.
The preliminary analysis yields the following results:
```
=============================================================
T_mid	Freq	Peak	r.m.s.	Beam		PA
[days]	[GHz]	[uJy/b]	[uJy/b]	[arcsec^2]	[deg]
=============================================================
0.76	6	51	7	0.65x0.27	-71
0.76	10	119	8	0.35x0.17	-78
0.76	15	163	8	0.24x0.12	-65
=============================================================
```
No source is detected with a >3sigma confidence at the aforementioned position in previous radio surveys (FIRST, NVSS, VLASS), all of which have r.m.s. noise levels above 100 uJy/b.
We would like to thank the staff of the VLA for approving, executing, and processing the observations.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
These observations were carried out as part of project SF171028, approved in the framework of the Fermi - NRAO joint program agreement.
GCN Circular #38162
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner= (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Obse= rvatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. H= usarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Reze= nov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research= Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (E= otvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (N= agoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. M= izuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K.= Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Grom= es (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration.
The long-duration GRB 241025A (Fermi/GBM detection: GCN 37886; Swift/BAT de= tection: GCN 37859; SVOM/GRM detection: GCN 37863; EP detection: GCN 37864;= Konus/Wind detection: GCN 37927) 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. The dete= ction was confirmed at the peak time 2024-10-25 01:36:50 UTC. The T90 durat= ion is 63 s and the significance during T90 reaches 10 sigma.
The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB241025A_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 Cub= eSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLU= SAT-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.
GCN Circular #38298
R. Querrard (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), K. Noonan (UVI), D. Smith (UVI), K. Smith (UVI), C. Watson (UVI) report:
We observed the field of GRB241025A detected by Swift (Ambrosi et al., GCN 37859), Fermi (Fermi GBM team, GCN 37860), SVOM (SVOM/GRM team, GCN 37863), and EP (Li et al., GCN 37864) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 2024-10-25 starting at 22:37:31 (T-mid ~T0+21.8 hrs). We performed a series of exposures in an R filter with a total exposure of 2800s. The weather conditions were partly cloudy during the hours of observation with an average airmass of 2.4.
We do not detect any source within the enhanced XRT position (Goad et al. GCN 37868). This non-detection is consistent with detections (Jiang et al. GCN 37862; Pereyra et al. GCN 37865; Xu et al. GCN 37866; Qiu et al. GCN 37871; Lipunov et al. GCN 37873; Qiu et al. GCN 37871; Abdi et al. GCN 37882; Alan et al. GCN 37889; Mohan et al. GCN 37890; Vinko et al. GCN 37891; Gupta et al. GCN 37893; Pankov et al. GCN 37912; Moskvitin et al. GCN 37914; Klingler et al. GCN 37919; Moskvitin et al. GCN 37923; Wang et al. GCN 37926; and Rossi et al. GCN 38114) and upper limits (Lipunov et al. GCN 37873) reported by others. We report the following 3-sigma upper limit:
```
T_mid                ||Exposure   ||Filter   ||Limit 
T+ 21.8 hrs          || 2800 s    || R       || > 19.8
```
The limit is estimated from comparison to nearby PANSTAARS and is not corrected for Galactic extinction. The VIRT is still in the commissioning phase.
We acknowledge financial support from NASA EPSCoR award 80NNSC22M0063, NSF PAARE award 2319415, and NASA EPSCoR award 80NSSC24M0112. We also acknowledge the use of STDWeb interface to verify our result. This message can be cited.

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Jochen Greiner, last update: 22-Nov-2024 [Disclaimer]