Gamma-ray Burst 210324C

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 24 Mar 21 20:00:22 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     638308803
GRB_RA:           40.733d {+02h 42m 56s} (J2000),
                  40.908d {+02h 43m 38s} (current),
                  40.322d {+02h 41m 17s} (1950)
GRB_DEC:         -51.633d {-51d 37' 59"} (J2000),
                 -51.544d {-51d 32' 37"} (current),
                 -51.845d {-51d 50' 41"} (1950)
GRB_ERROR:       14.13 [deg radius, statistical plus systematic]
GRB_INTEN:       74 [cnts/sec]
DATA_SIGNIF:     6.50 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         290.00 [deg]
GRB_THETA:        35.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.83
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic Transient
DETECTORS:       0,0,0, 0,1,0, 0,1,0, 0,0,0, 0,0,
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 57"}
SUN_DIST:         61.74 [deg]   Sun_angle= -2.5 [hr] (East of Sun)
MOON_POSTN:      135.87d {+09h 03m 30s}  +21.31d {+21d 18' 37"}
MOON_DIST:       109.56 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      269.98,-57.76 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        7.24,-61.70 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 181.20,-19.28 [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 24 Mar 21 20:00:32 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      59
TRIGGER_NUM:     638308803
GRB_RA:           46.350d {+03h 05m 24s} (J2000),
                  46.546d {+03h 06m 11s} (current),
                  45.889d {+03h 03m 33s} (1950)
GRB_DEC:         -41.717d {-41d 43' 00"} (J2000),
                 -41.635d {-41d 38' 06"} (current),
                 -41.910d {-41d 54' 34"} (1950)
GRB_ERROR:       6.30 [deg radius, statistical plus systematic]
GRB_INTEN:       348 [cnts/sec]
DATA_SIGNIF:     22.70 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         295.00 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.38
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      94%  GRB
2nd_MOST_LIKELY:   3%  Distant Particles
DETECTORS:       0,0,0, 0,1,0, 0,1,0, 0,0,0, 0,0,
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 57"}
SUN_DIST:         57.96 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      135.88d {+09h 03m 30s}  +21.31d {+21d 18' 36"}
MOON_DIST:       103.49 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      249.75,-59.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       24.13,-55.63 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 181.20,-19.28 [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 24 Mar 21 20:00:41 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     638308803
GRB_RA:           41.040d {+02h 44m 10s} (J2000),
                  41.249d {+02h 45m 00s} (current),
                  40.547d {+02h 42m 11s} (1950)
GRB_DEC:         -38.920d {-38d 55' 11"} (J2000),
                 -38.831d {-38d 49' 51"} (current),
                 -39.131d {-39d 07' 50"} (1950)
GRB_ERROR:       3.92 [deg radius, statistical only]
DATA_SIGNIF:     16.30 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         302.00 [deg]
GRB_THETA:        45.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 57"}
SUN_DIST:         53.06 [deg]   Sun_angle= -2.5 [hr] (East of Sun)
MOON_POSTN:      135.88d {+09h 03m 31s}  +21.31d {+21d 18' 34"}
MOON_DIST:       106.64 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      246.78,-63.74 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       20.45,-51.22 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_638308803.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:     Wed 24 Mar 21 20:01:00 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      91
TRIGGER_NUM:     638308803
GRB_RA:           40.950d {+02h 43m 48s} (J2000),
                  41.129d {+02h 44m 31s} (current),
                  40.529d {+02h 42m 07s} (1950)
GRB_DEC:         -50.217d {-50d 13' 00"} (J2000),
                 -50.128d {-50d 07' 38"} (current),
                 -50.428d {-50d 25' 39"} (1950)
GRB_ERROR:       4.70 [deg radius, statistical plus systematic]
GRB_INTEN:       678 [cnts/sec]
DATA_SIGNIF:     55.10 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         290.00 [deg]
GRB_THETA:        35.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.73
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   2%  Generic Transient
DETECTORS:       0,0,0, 0,1,0, 0,1,0, 0,0,0, 0,0,
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 58"}
SUN_DIST:         60.81 [deg]   Sun_angle= -2.5 [hr] (East of Sun)
MOON_POSTN:      135.88d {+09h 03m 31s}  +21.31d {+21d 18' 32"}
MOON_DIST:       109.17 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      267.69,-58.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        9.29,-60.68 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 181.20,-19.28 [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 24 Mar 21 20:00:46 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      70
TRIGGER_NUM:     638308803
GRB_RA:           45.850d {+03h 03m 24s} (J2000),
                  46.031d {+03h 04m 07s} (current),
                  45.424d {+03h 01m 42s} (1950)
GRB_DEC:         -47.067d {-47d 04' 00"} (J2000),
                 -46.985d {-46d 59' 03"} (current),
                 -47.261d {-47d 15' 40"} (1950)
GRB_ERROR:       5.88 [deg radius, statistical plus systematic]
GRB_INTEN:       444 [cnts/sec]
DATA_SIGNIF:     34.70 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         290.00 [deg]
GRB_THETA:        40.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.46
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      93%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,1,0, 0,1,0, 0,0,0, 0,0,
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 58"}
SUN_DIST:         61.02 [deg]   Sun_angle= -2.8 [hr] (East of Sun)
MOON_POSTN:      135.88d {+09h 03m 31s}  +21.31d {+21d 18' 34"}
MOON_DIST:       105.31 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      259.45,-57.39 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       18.33,-60.01 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 181.20,-19.28 [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 24 Mar 21 20:01:29 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     638308803
GRB_RA:           41.330d {+02h 45m 19s} (J2000),
                  41.519d {+02h 46m 05s} (current),
                  40.884d {+02h 43m 32s} (1950)
GRB_DEC:         -46.680d {-46d 40' 47"} (J2000),
                 -46.591d {-46d 35' 28"} (current),
                 -46.890d {-46d 53' 22"} (1950)
GRB_ERROR:       3.65 [deg radius, statistical only]
DATA_SIGNIF:     13.50 [sigma]
DATA_INTERVAL:   9.216 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         295.00 [deg]
GRB_THETA:        39.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 58"}
SUN_DIST:         58.47 [deg]   Sun_angle= -2.5 [hr] (East of Sun)
MOON_POSTN:      135.89d {+09h 03m 33s}  +21.31d {+21d 18' 28"}
MOON_DIST:       108.22 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      261.65,-60.28 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       13.77,-57.96 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_638308803.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 24 Mar 21 20:01:39 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      1
TRIGGER_NUM:     638308803
GRB_RA:           44.080d {+02h 56m 19s} (J2000),
                  44.278d {+02h 57m 07s} (current),
                  43.613d {+02h 54m 27s} (1950)
GRB_DEC:         -41.870d {-41d 52' 11"} (J2000),
                 -41.785d {-41d 47' 06"} (current),
                 -42.071d {-42d 04' 14"} (1950)
GRB_ERROR:       3.49 [deg radius, statistical only]
DATA_SIGNIF:     24.10 [sigma]
DATA_INTERVAL:   11.264 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         297.00 [deg]
GRB_THETA:        44.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 58"}
SUN_DIST:         56.73 [deg]   Sun_angle= -2.7 [hr] (East of Sun)
MOON_POSTN:      135.89d {+09h 03m 33s}  +21.31d {+21d 18' 27"}
MOON_DIST:       105.17 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      251.12,-60.59 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       21.41,-54.93 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_638308803.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 24 Mar 21 20:01:50 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      2
TRIGGER_NUM:     638308803
GRB_RA:           40.590d {+02h 42m 22s} (J2000),
                  40.782d {+02h 43m 08s} (current),
                  40.138d {+02h 40m 33s} (1950)
GRB_DEC:         -46.160d {-46d 09' 35"} (J2000),
                 -46.070d {-46d 04' 12"} (current),
                 -46.372d {-46d 22' 19"} (1950)
GRB_ERROR:       2.89 [deg radius, statistical only]
DATA_SIGNIF:     33.00 [sigma]
DATA_INTERVAL:   16.384 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         296.00 [deg]
GRB_THETA:        39.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 59"}
SUN_DIST:         57.74 [deg]   Sun_angle= -2.4 [hr] (East of Sun)
MOON_POSTN:      135.89d {+09h 03m 33s}  +21.31d {+21d 18' 25"}
MOON_DIST:       108.62 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      261.28,-60.99 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       13.53,-57.25 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_638308803.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 24 Mar 21 20:02:04 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      3
TRIGGER_NUM:     638308803
GRB_RA:           39.170d {+02h 36m 41s} (J2000),
                  39.367d {+02h 37m 28s} (current),
                  38.707d {+02h 34m 50s} (1950)
GRB_DEC:         -45.250d {-45d 15' 00"} (J2000),
                 -45.159d {-45d 09' 30"} (current),
                 -45.467d {-45d 27' 59"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     37.10 [sigma]
DATA_INTERVAL:   22.528 [sec]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         298.00 [deg]
GRB_THETA:        39.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:         4.04d {+00h 16m 10s}   +1.75d {+01d 44' 59"}
SUN_DIST:         56.40 [deg]   Sun_angle= -2.4 [hr] (East of Sun)
MOON_POSTN:      135.89d {+09h 03m 34s}  +21.31d {+21d 18' 23"}
MOON_DIST:       109.41 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      260.74,-62.31 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       12.95,-55.94 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_638308803.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 24 Mar 21 20:09:25 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     638308803
GRB_RA:           37.570d {+02h 30m 17s} (J2000),
                  37.767d {+02h 31m 04s} (current),
                  37.105d {+02h 28m 25s} (1950)
GRB_DEC:         -45.990d {-45d 59' 23"} (J2000),
                 -45.896d {-45d 53' 46"} (current),
                 -46.211d {-46d 12' 40"} (1950)
GRB_ERROR:       1.83 [deg radius, statistical only]
GRB_DATE:        19297 TJD;    83 DOY;   21/03/24
GRB_TIME:        71998.32 SOD {19:59:58.32} UT
GRB_PHI:         298.00 [deg]
GRB_THETA:        37.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:         4.05d {+00h 16m 11s}   +1.75d {+01d 45' 06"}
SUN_DIST:         56.18 [deg]   Sun_angle= -2.2 [hr] (East of Sun)
MOON_POSTN:      135.96d {+09h 03m 51s}  +21.29d {+21d 17' 23"}
MOON_DIST:       110.68 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      263.43,-62.83 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       10.55,-55.93 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_locplot_all_bn210324833.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.

GCN Circular #29718
The Fermi GBM team reports the detection of a likely LONG GRB
At 19:59:58 UT on 24 Mar 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210324C (trigger 638308803.321686 / 210324833).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 37.6, Dec = -46.0 (J2000 degrees, equivalent to J2000 02h 30m, -46d 00'), with a statistical uncertainty of 1.8 degrees.
The angle from the Fermi LAT boresight is 37.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_skymap_all_bn210324833.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_healpix_all_bn210324833.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210324833/quicklook/glg_lc_medres34_bn210324833.gif
GCN Circular #29719
F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 638308803 at 19:59:58 on 24 March 2021 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
```
RA(2000.0) = 43.2+/-0.6 deg
Decl.(2000.0) = -48.1+/-0.5 deg
```
We estimate an additional systematic error of 2 deg.
Further details are available at: https://grb.mpe.mpg.de/grb/GRB210324833/
The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB210324833/healpix
The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB210324833/json
GCN Circular #29723
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 210324C ( Fermi GBM team, GCN 29718) errorbox 2759 sec after notice time and 2786 sec after trigger time at 2021-03-24 20:46:24 UT, with upper limit up to 17.1 mag. The observations began at zenith distance = 81 deg. The sun altitude is -48.8 deg.
The galactic latitude b = -63 deg., longitude l = 263 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1576010
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    2876 | 2021-03-24 20:46:24 |         MASTER-SAAO | (02h 45m 04.74s , -47d 04m 20.4s) |   C |   180 | 17.1 |        
    3076 | 2021-03-24 20:49:44 |         MASTER-SAAO | (02h 44m 59.67s , -47d 05m 16.2s) |   C |   180 | 16.7 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #29727
K. Hurley, on behalf of the IPN,
I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
A. Ridnaia, S. Golenetskii, D. Frederiks, D. Svinkin, A. Lysenko, and T. Cline on behalf of the Konus-Wind team,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report:
The long-duration GRB 210324C (Fermi-GBM detection: The Fermi GBM team, GCN Circ. 29718; BALROG localization: Kunzweileret et al., GCN Circ. 29719) has been detected by Fermi (GBM trigger 638308803), INTEGRAL (SPI-ACS), Konus-Wind, and Mars-Odyssey (HEND), so far, at about 71998 s UT (19:59:58).
We have triangulated it to a preliminary, 3 sigma error box whose coordinates are:
```
---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
   35.111 (02h 20m 27s) -48.606 (-48d 36' 21")
 Corners:
   43.843 (02h 55m 22s) -51.173 (-51d 10' 22")
   43.444 (02h 53m 46s) -51.998 (-51d 59' 54")
   27.400 (01h 49m 36s) -45.327 (-45d 19' 38")
   27.969 (01h 51m 53s) -44.554 (-44d 33' 15")
 ---------------------------------------------
```
The error box area is 10.7 sq. deg, and its maximum dimension is 12.7 deg (the minimum one is 51 arcmin). The Sun distance was 51 deg.
This box may be improved.
The IPN localization is consistent with, but reduces the area of, the Fermi RoboBA and BALROG localizations (GCN Circ. 29718 and 29719).
A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB210324_T72000/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
GCN Circular #29728
D. Frederiks, S. Golenetskii, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long GRB 210324C (IPN triangulation: Hurley et al., GCN 29727) triggered Konus-Wind (KW) at T0=72000.034 s UT (20:00:00.034).
The burst light curve shows a multi-peaked structure with the total duration of ~75 s. The emission is seen up to ~10 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB210324_T72000/
As observed by Konus-Wind, the burst had a fluence of (7.0 � 0.6)x10^-5 erg/cm^2 and a 64-ms peak energy flux, measured from T0+34.112, of (3.4 � 0.4)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+65.024 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.51 (-0.10,+0.11), the high energy photon index beta = -2.69 (-0.28,+0.18), the peak energy Ep = 190 (-11,+12) keV, chi2 = 97/97 dof.
The spectrum near the peak count rate (measured from T0+33.024 to T0+40.448 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.56 (-0.15,+0.17), the high energy photon index beta = -2.64 (-0.53,+0.24), the peak energy Ep = 211 (-21,+26) keV, chi2 = 108/97 dof.
All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.
GCN Circular #29734
P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), S. Gupta (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al, 2020, arxiv:2011.07067) showed detection of a long GRB 210324C, which was also detected by Fermi-GBM (GCN #29718), and Konus-Wind (GCN #29728).
The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2021-03-24 20:00:36.50 UT. The measured peak count rate associated with the burst is 214 (+47, -35) cts/s above the background in the combined data of four quadrants, with a total 4856 (+784, -875) cts. The local mean background count rate was 604 (+3, -3) cts/s. Using cumulative rates, we measure a T90 of 63 (+14, -11) s.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.

Back to JG's homepage

Jochen Greiner, last update: 30-Mar-2021 [Disclaimer]