Gamma-ray Burst 200411A

(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:     Sat 11 Apr 20 04:29:19 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     965784,   Seg_Num: 0
GRB_RA:           47.659d {+03h 10m 38s} (J2000),
                  47.811d {+03h 11m 15s} (current),
                  47.285d {+03h 09m 08s} (1950)
GRB_DEC:         -52.314d {-52d 18' 51"} (J2000),
                 -52.238d {-52d 14' 18"} (current),
                 -52.503d {-52d 30' 08"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       589 [cnts]    Image_Peak=94 [image_cnts]
TRIGGER_DUR:     0.064 [sec] 
TRIGGER_INDEX:   10418     E_range: 25-100 keV
BKG_INTEN:       18272 [cnts]
BKG_TIME:        16127.24 SOD {04:28:47.24} UT
BKG_DUR:         8 [sec]
GRB_DATE:        18950 TJD;   102 DOY;   20/04/11
GRB_TIME:        16142.28 SOD {04:29:02.28} UT
GRB_PHI:         -161.70 [deg]
GRB_THETA:         8.30 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     34.97 [sigma]
IMAGE_SIGNIF:    10.06 [sigma]
MERIT_PARAMS:     +1  +0  +0  -4  +2  +0  +0  +0 -41  +0 
SUN_POSTN:        20.11d {+01h 20m 26s}   +8.48d {+08d 28' 36"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.27d {+16h 13m 04s}  -18.75d {-18d 45' 12"}
MOON_DIST:       107.74 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.66,-53.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       13.62,-64.93 [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 = 122.52,-19.90 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:29:27 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     608272147
GRB_RA:           64.983d {+04h 19m 56s} (J2000),
                  64.965d {+04h 19m 52s} (current),
                  65.032d {+04h 20m 08s} (1950)
GRB_DEC:         -69.833d {-69d 49' 59"} (J2000),
                 -69.786d {-69d 47' 07"} (current),
                 -69.951d {-69d 57' 02"} (1950)
GRB_ERROR:       20.20 [deg radius, statistical plus systematic]
GRB_INTEN:       1966 [cnts/sec]
DATA_SIGNIF:     10.90 [sigma]
INTEG_TIME:      0.032 [sec]
GRB_DATE:        18950 TJD;   102 DOY;   20/04/11
GRB_TIME:        16142.52 SOD {04:29:02.52} UT
GRB_PHI:          14.00 [deg]
GRB_THETA:       135.00 [deg]
DATA_TIME_SCALE: 0.0320 [sec]
HARD_RATIO:      0.45
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
SUN_POSTN:        20.11d {+01h 20m 26s}   +8.48d {+08d 28' 36"}
SUN_DIST:         84.03 [deg]   Sun_angle= -3.0 [hr] (East of Sun)
MOON_POSTN:      243.27d {+16h 13m 04s}  -18.75d {-18d 45' 13"}
MOON_DIST:        91.45 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      282.71,-38.05 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      329.24,-80.23 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_lc_medres34_bn200411187.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=965784).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:29:46 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      59
TRIGGER_NUM:     608272147
GRB_RA:           41.690d {+02h 46m 46s} (J2000),
                  41.852d {+02h 47m 24s} (current),
                  41.292d {+02h 45m 10s} (1950)
GRB_DEC:         -52.620d {-52d 37' 11"} (J2000),
                 -52.536d {-52d 32' 08"} (current),
                 -52.829d {-52d 49' 42"} (1950)
GRB_ERROR:       11.37 [deg radius, statistical only]
DATA_SIGNIF:     12.00 [sigma]
DATA_INTERVAL:   0.032 [sec]
GRB_DATE:        18950 TJD;   102 DOY;   20/04/11
GRB_TIME:        16142.52 SOD {04:29:02.52} UT
GRB_PHI:          10.00 [deg]
GRB_THETA:       115.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:        20.11d {+01h 20m 26s}   +8.48d {+08d 28' 36"}
SUN_DIST:         63.78 [deg]   Sun_angle= -1.4 [hr] (East of Sun)
MOON_POSTN:      243.27d {+16h 13m 05s}  -18.75d {-18d 45' 16"}
MOON_DIST:       106.32 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      270.72,-56.69 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        6.84,-62.83 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_lc_medres34_bn200411187.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_608272147.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=965784).

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Sat 11 Apr 20 04:29:48 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    8587,   Sub_Num: 0
GRB_INTEN:      9.97 [sigma]   
GRB_TIME:       16143.07 SOD {04:29:03.07} UT
GRB_DATE:       18950 TJD;   102 DOY;   20/04/11
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:       Time_Scale=0.0500 and Time_Error=0.0250.
COMMENTS:
COMMENTS:       NOTE: This SPIACS event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=608272147).
COMMENTS:
COMMENTS:       The SPIACS lightcurve can be found at:
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2020-04/2020-04-11T04-29-02.9305-19176-56208-0.lc

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:38:26 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     608272147
GRB_RA:           69.580d {+04h 38m 19s} (J2000),
                  69.654d {+04h 38m 37s} (current),
                  69.398d {+04h 37m 35s} (1950)
GRB_DEC:         -60.320d {-60d 19' 11"} (J2000),
                 -60.281d {-60d 16' 49"} (current),
                 -60.418d {-60d 25' 02"} (1950)
GRB_ERROR:       24.08 [deg radius, statistical only]
GRB_DATE:        18950 TJD;   102 DOY;   20/04/11
GRB_TIME:        16142.52 SOD {04:29:02.52} UT
GRB_PHI:          23.00 [deg]
GRB_THETA:       128.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:        20.12d {+01h 20m 28s}   +8.48d {+08d 28' 44"}
SUN_DIST:         79.04 [deg]   Sun_angle= -3.3 [hr] (East of Sun)
MOON_POSTN:      243.36d {+16h 13m 26s}  -18.78d {-18d 46' 35"}
MOON_DIST:       100.78 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      270.41,-39.64 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       24.89,-79.02 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_lc_medres34_bn200411187.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_locplot_all_bn200411187.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:        This is likely a Short GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=8587).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:30:26 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     965784,   Seg_Num: 0
GRB_RA:           47.6735d {+03h 10m 41.63s} (J2000),
                  47.8253d {+03h 11m 18.07s} (current),
                  47.2995d {+03h 09m 11.87s} (1950)
GRB_DEC:         -52.3073d {-52d 18' 26.2"} (J2000),
                 -52.2314d {-52d 13' 53.0"} (current),
                 -52.4954d {-52d 29' 43.5"} (1950)
GRB_ERROR:       5.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.42e-09 [erg/cm2/sec]
GRB_SIGNIF:      5.09 [sigma]
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16193.04 SOD {04:29:53.04} UT,   50.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.64 237.22 261.67 243.29
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        20.11d {+01h 20m 27s}   +8.48d {+08d 28' 37"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.28d {+16h 13m 07s}  -18.76d {-18d 45' 22"}
MOON_DIST:       107.75 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.64,-53.86 [deg] galactic lon,lat of the burst
ECL_COORDS:       13.65,-64.93 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.67 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:30:35 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     965784,   Seg_Num: 0
GRB_RA:           47.6735d {+03h 10m 41.6s} (J2000),
                  47.8253d {+03h 11m 18.0s} (current),
                  47.2995d {+03h 09m 11.8s} (1950)
GRB_DEC:         -52.3073d {-52d 18' 26.2"} (J2000),
                 -52.2314d {-52d 13' 53.0"} (current),
                 -52.4954d {-52d 29' 43.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       26 [cnts]
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16193.04 SOD {04:29:53.04} UT,   50.8 [sec] since BAT Trigger Time
CENTROID_X:      306.16,  raw= 306  [pixels]
CENTROID_Y:      290.50,  raw= 291  [pixels]
ROLL:            329.71 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -17.89
GRB_POS_XRT_Z:   -2.91
IMAGE_URL:       sw00965784000msxps_rw.img
SUN_POSTN:        20.11d {+01h 20m 27s}   +8.48d {+08d 28' 37"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.28d {+16h 13m 07s}  -18.76d {-18d 45' 23"}
MOON_DIST:       107.75 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.64,-53.86 [deg] galactic lon,lat of the burst
ECL_COORDS:       13.65,-64.93 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:30:41 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     965784,   Seg_Num: 0
GRB_RA:           47.6735d {+03h 10m 41.6s} (J2000),
                  47.8253d {+03h 11m 18.0s} (current),
                  47.2995d {+03h 09m 11.8s} (1950)
GRB_DEC:         -52.3073d {-52d 18' 26.2"} (J2000),
                 -52.2314d {-52d 13' 53.0"} (current),
                 -52.4954d {-52d 29' 43.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       26 [cnts]
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16193.04 SOD {04:29:53.04} UT,   50.8 [sec] since BAT Trigger Time
CENTROID_X:      306.16,  raw= 306  [pixels]
CENTROID_Y:      290.50,  raw= 291  [pixels]
ROLL:            329.71 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -17.89
GRB_POS_XRT_Z:   -2.91
IMAGE_URL:       sw00965784000msxps_rw.img
SUN_POSTN:        20.11d {+01h 20m 27s}   +8.48d {+08d 28' 37"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.28d {+16h 13m 07s}  -18.76d {-18d 45' 24"}
MOON_DIST:       107.75 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.64,-53.86 [deg] galactic lon,lat of the burst
ECL_COORDS:       13.65,-64.93 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:33:06 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.667d {+03h 10m 40s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 34"} (J2000)
POINT_ROLL:      329.708d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16200.32 SOD {04:30:00.32} UT,   58.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.986
N_STARS:         35
X_OFFSET:        448 [pixels]
Y_OFFSET:        504 [pixels]
X_MAX:           1407 [pixels]
Y_MAX:           1463 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00965784000msufc0058.fits
SUN_POSTN:        20.11d {+01h 20m 27s}   +8.48d {+08d 28' 39"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.30d {+16h 13m 13s}  -18.76d {-18d 45' 46"}
MOON_DIST:       107.73 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:33:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.667d {+03h 10m 40s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 34"} (J2000)
POINT_ROLL:      329.708d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16200.32 SOD {04:30:00.32} UT,   58.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.986
N_STARS:         35
X_OFFSET:        448 [pixels]
Y_OFFSET:        504 [pixels]
X_MAX:           1407 [pixels]
Y_MAX:           1463 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00965784000msufc0058.fits
SUN_POSTN:        20.11d {+01h 20m 27s}   +8.48d {+08d 28' 40"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.31d {+16h 13m 14s}  -18.76d {-18d 45' 49"}
MOON_DIST:       107.73 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [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:     Sat 11 Apr 20 04:35:53 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     965784,   Seg_Num: 0
GRB_RA:           47.659d {+03h 10m 38s} (J2000),
                  47.811d {+03h 11m 15s} (current),
                  47.285d {+03h 09m 08s} (1950)
GRB_DEC:         -52.314d {-52d 18' 51"} (J2000),
                 -52.238d {-52d 14' 18"} (current),
                 -52.503d {-52d 30' 08"} (1950)
GRB_DATE:        18950 TJD;   102 DOY;   20/04/11
GRB_TIME:        16142.45 SOD {04:29:02.45} UT
TRIGGER_INDEX:   10418
GRB_PHI:         -161.70 [deg]
GRB_THETA:         8.30 [deg]
DELTA_TIME:      80.00 [sec]
TRIGGER_DUR:     0.064 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     34.97 [sigma]
IMAGE_SIGNIF:    10.06 [sigma]
LC_URL:          sw00965784000msb.lc
SUN_POSTN:        20.11d {+01h 20m 27s}   +8.48d {+08d 28' 42"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.33d {+16h 13m 20s}  -18.77d {-18d 46' 11"}
MOON_DIST:       107.71 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.66,-53.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       13.62,-64.93 [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 = 122.52,-19.90 [deg].

GCN Circular #27535
The Fermi GBM team reports the detection of a likely SHORT GRB
At 04:29:02 UT on 11 Apr 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200411A (trigger 608272147.522124 / 200411187).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 69.6, Dec = -60.3 (J2000 degrees, equivalent to J2000 04h 38m, -60d 17'), with a statistical uncertainty of 24.1 degrees.
The angle from the Fermi LAT boresight is 128.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_skymap_all_bn200411187.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_healpix_all_bn200411187.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200411187/quicklook/glg_lc_medres34_bn200411187.gif

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:42:38 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.671d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
POINT_ROLL:      329.705d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16412.35 SOD {04:33:32.35} UT,   270.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.558
N_STARS:         15
X_OFFSET:        496 [pixels]
Y_OFFSET:        568 [pixels]
X_MAX:           1455 [pixels]
Y_MAX:           1527 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00965784000msufc0270.fits
SUN_POSTN:        20.12d {+01h 20m 28s}   +8.48d {+08d 28' 48"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.40d {+16h 13m 36s}  -18.79d {-18d 47' 13"}
MOON_DIST:       107.69 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:42:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.671d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
POINT_ROLL:      329.705d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16412.35 SOD {04:33:32.35} UT,   270.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.558
N_STARS:         15
X_OFFSET:        496 [pixels]
Y_OFFSET:        568 [pixels]
X_MAX:           1455 [pixels]
Y_MAX:           1527 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00965784000msufc0270.fits
SUN_POSTN:        20.12d {+01h 20m 28s}   +8.48d {+08d 28' 48"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.40d {+16h 13m 37s}  -18.79d {-18d 47' 14"}
MOON_DIST:       107.69 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:43:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.671d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
ROLL:            329.705d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16412.35 SOD {04:33:32.35} UT,   270.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     608272437
X_OFFSET:        816 [pixels]
Y_OFFSET:        888 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       976
Y_GRB_POS:       1048
BINNING_INDEX:   1
IM_URL:          sw00965784000msuni0295.fits
SUN_POSTN:        20.12d {+01h 20m 29s}   +8.48d {+08d 28' 49"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.42d {+16h 13m 40s}  -18.79d {-18d 47' 25"}
MOON_DIST:       107.69 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #27536
A. Tohuvavohu (U Toronto), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), N. J. Klingler (PSU), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and T. N. Ukwatta (LANL) report on behalf of the Neil Gehrels Swift Observatory Team:
At 04:29:02 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200411A (trigger=965784). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 47.659, -52.314, which is
```
   RA(J2000)  =  03h 10m 38s
   Dec(J2000) = -52d 18' 51"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 0.5 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 04:29:53.0 UT, 50.7 seconds after the BAT trigger. The position determined from promptly downlinked data differs significantly from the on-board position, suggesting that the XRT may have centroided on a cosmic ray; the initial XRT position notice should be treated with caution. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 47.66239, -52.31805 which is equivalent to:
```
   RA(J2000)  = 03h 10m 38.97s
   Dec(J2000) = -52d 19' 05.0"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 16 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.55 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.4 (+5.14/-3.83) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of nominal 150.000 seconds with the White filter starting 58 seconds after the BAT trigger. Further analysis is required before any results can be obtained.
Burst Advocate for this burst is A. Tohuvavohu (tohuvavohu AT astro.utoronto.ca). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:50:32 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.670d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
POINT_ROLL:      329.707d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  17014.68 SOD {04:43:34.68} UT,   872.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.448
N_STARS:         40
X_OFFSET:        256 [pixels]
Y_OFFSET:        328 [pixels]
X_MAX:           1695 [pixels]
Y_MAX:           1767 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00965784000msufc0872.fits
SUN_POSTN:        20.12d {+01h 20m 30s}   +8.48d {+08d 28' 55"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.48d {+16h 13m 56s}  -18.81d {-18d 48' 24"}
MOON_DIST:       107.66 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 11 Apr 20 04:50:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.670d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
POINT_ROLL:      329.707d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  17014.68 SOD {04:43:34.68} UT,   872.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.448
N_STARS:         40
X_OFFSET:        256 [pixels]
Y_OFFSET:        328 [pixels]
X_MAX:           1695 [pixels]
Y_MAX:           1767 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00965784000msufc0872.fits
SUN_POSTN:        20.12d {+01h 20m 30s}   +8.48d {+08d 28' 55"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.49d {+16h 13m 57s}  -18.81d {-18d 48' 27"}
MOON_DIST:       107.66 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [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:     Sat 11 Apr 20 04:51:56 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.670d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
ROLL:            329.707d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  17014.68 SOD {04:43:34.68} UT,   872.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     608273039
X_OFFSET:        815 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       975
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00965784000msuni0897.fits
SUN_POSTN:        20.12d {+01h 20m 30s}   +8.48d {+08d 28' 56"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.50d {+16h 13m 59s}  -18.81d {-18d 48' 37"}
MOON_DIST:       107.65 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [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:     Sat 11 Apr 20 04:52:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     965784,   Seg_Num: 0
POINT_RA:         47.670d {+03h 10m 41s} (J2000)
POINT_DEC:       -52.310d {-52d 18' 35"} (J2000)
ROLL:            329.707d
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  17014.68 SOD {04:43:34.68} UT,   872.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     608273039
X_OFFSET:        815 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       975
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00965784000msuni0897.fits
SUN_POSTN:        20.12d {+01h 20m 30s}   +8.48d {+08d 28' 57"}
SUN_DIST:         65.18 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.50d {+16h 14m 00s}  -18.81d {-18d 48' 39"}
MOON_DIST:       107.65 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      266.65,-53.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       13.64,-64.93 [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:     Sat 11 Apr 20 05:10:17 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     965784,   Seg_Num: 0
GRB_RA:           47.6640d {+03h 10m 39.36s} (J2000),
                  47.8158d {+03h 11m 15.78s} (current),
                  47.2900d {+03h 09m 09.60s} (1950)
GRB_DEC:         -52.3186d {-52d 19' 06.9"} (J2000),
                 -52.2427d {-52d 14' 33.6"} (current),
                 -52.5068d {-52d 30' 24.3"} (1950)
GRB_ERROR:       3.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18950 TJD;   102 DOY;   20/04/11
IMG_START_TIME:  16213.00 SOD {04:30:13.00} UT,   70.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        20.14d {+01h 20m 33s}   +8.49d {+08d 29' 13"}
SUN_DIST:         65.19 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      243.68d {+16h 14m 44s}  -18.86d {-18d 51' 23"}
MOON_DIST:       107.57 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:      266.66,-53.86 [deg] galactic lon,lat of the burst
ECL_COORDS:       13.62,-64.94 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #27538
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 980 s of XRT Photon Counting mode data and 2 UVOT images for GRB 200411A, 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 = 47.66418, -52.31764 which is equivalent to:
```
RA (J2000): 03h 10m 39.40s
Dec (J2000): -52d 19' 03.5"
```
with an uncertainty of 1.5 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 #27539
N. P. M. Kuin (UCL-MSSL) and A. Tohuvavohu (U. Toronto) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 200411A 58 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 27536). No optical afterglow consistent with the XRT position (Osborne et al., GCN Circ. 27538) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            58          208          147         >20.8
u_FC               270          520          246         >20.4
white               58         1540          392         >21.2
v                  601         1417           97         >18.5
b                  525         1343           78         >20.3
u                  270         1490          343         >21.0
w1                 651         1466           97         >18.8
m2                 626          646           19         >18.1
w2                 576         1220           58         >19.2
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #27540
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), J.A. Kennea (PSU), B. Sbarufatti (PSU) and A. Tohuvavohu report on behalf of the Swift-XRT team:
We have analysed 6.6 ks of XRT data for GRB 200411A (Tohuvavohu et al. GCN Circ. 27536), from 39 s to 13.0 ks after the BAT trigger. The data comprise 8 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 27538).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.16 (+0.11, -0.10).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.74 (+0.25, -0.24). The best-fitting absorption column is 1.3 (+0.9, -0.7) x 10^21 cm^-2, in excess of the Galactic value of 1.6 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (4.7 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.3 (+0.9, -0.7) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^20 cm^-2
Excess significance: 2.6 sigma
Photon index:	     1.74 (+0.25, -0.24)
```
If the light curve continues to decay with a power-law decay index of 1.16, the count rate at T+24 hours will be 4.9 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x 10^-14 (2.3 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00965784.
This circular is an official product of the Swift-XRT team.
GCN Circular #27542
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),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
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) was pointed to the Swift GRB 200411A ( A. Tohuvavohu et al., GCN 27536) errorbox 46681 sec after notice time and 46701 sec after trigger time at 2020-04-11 17:27:24 UT, with upper limit up to 18.9 mag. Observations started at twilight. The observations began at zenith distance = 56 deg. The sun altitude is -14.6 deg.
The galactic latitude b = -54 deg., longitude l = 266 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1334193
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   46792 |         MASTER-SAAO |   C |   180 | 18.9 |        
   46794 |         MASTER-SAAO |   C |   180 | 18.9 |        
   47360 |         MASTER-SAAO |   C |   180 | 17.8 |        
   47363 |         MASTER-SAAO |   C |   180 | 17.8 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #27543
E. Bissaldi (Politecnico and INFN Bari), C. Meegan (UAH), and J. Wood (NASA/MSFC) report on behalf of the Fermi GBM Team:
"At 04:29:02.52 UT on 11 April 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200411A (trigger 608272147 / 200411187), which was also detected by the Swift/BAT (Tohuvavohu et al. 2020, GCN 27536) The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 116 degrees.
The GBM light curve shows a single pulse with a duration (T90) of about 1.4 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.192 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.64 +/- 0.22 and the cutoff energy, parameterized as Epeak, is 420 +/- 120 keV.
The event fluence (10-1000 keV) in this time interval is (4.7 +/- 0.6)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 11.9 +/- 1.5 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular #27545
H. A. Krimm (NSF), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), J. P. Norris (BSU), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), A. Tohuvavohu (U Toronto), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+880 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200411A (trigger #965784) (Tohuvavohu et al., GCN Circ. 27536). The BAT ground-calculated position is RA, Dec = 47.686, -52.320 deg which is
```
   RA(J2000)  =  03h 10m 44.7s
   Dec(J2000) = -52d 19' 12.6"
```
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a couple overlapping pulses that starts at ~T-0.02 s and ends at ~T+0.25 s. The highest peak occurs at ~ T+0.05 s. T90 (15-350 keV) is 0.22 +- 0.04 sec (estimated error including systematics).
The time-averaged spectrum from T-0.02 to T+0.25 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.95 +- 0.19. The fluence in the 15-150 keV band is 8.6 +- 1.1 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.38 sec in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
Using the 4-ms binned light curve, the spectral lag of the short pulse is 1 (+7, -4) ms for the 100-350 keV to 25-50 keV bands, and 8 (+6, -6) ms for the 50-100 keV to 15-25 keV bands. These values are more consistent with those of short GRBs.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/965784/BA/
GCN Circular #27573
G. E. Anderson (Curtin), M. E. Bell (UTS), J. Stevens (CASS), P. J. Hancock (Curtin), J. C. A. Miller-Jones (Curtin), M. D. Aksulu (UvA), A. Bahramian (Curtin), K. W. Bannister (CASS), A. J. van der Horst (GWU), S. D. Ryder (Macquarie), J-P. Macquart (Curtin), R. M. Plotkin (UNR), A. Rowlinson (UvA), R. A. M. J. Wijers (UvA)
We used the Australia Telescope Compact Array (ATCA) to perform a radio observation of the short GRB 200411A. The rapidly scheduled observations began on 2020 Apr 11.25 UT for 5 hours (1.5 hrs post-burst; Fermi GBM Team GCN 27535, A. Tohuvavohu et al., GCN 27536). No radio source was detected at the enhanced Swift-XRT position (J.P. Osborne et al., GCN 27538), with preliminary 3 sigma upper-limits of 45 microJy and 36 microJy at 5.5 and 9 GHz, respectively. Further observations are planned.
We thank the ATCA and CSIRO Astronomy and Space Science (CASS) staff for scheduling these observations.
GCN Circular #27589
A. Rouco Escorial, W. Fong (Northwestern), and E. Berger (Harvard) report:
“We initiated observations with the Chandra X-ray Observatory of the position of the short-duration GRB 200411A (Fermi-GBM et al., GCN 27535; Tohuvavohu et al., GCN 27536; Bissaldi et al., GCN 27543) starting on 2020 April 15 00:16:54 UT, or at a mid-time of 3.95 days after the GRB trigger. ACIS-S observations were taken under Proposal 21500089 (ObsID 22427; PI: Berger), with a total exposure time of 19.8 ksec.
We do not detect an X-ray source within or around the enhanced Swift-XRT position (90% confidence; Osborne et al., GCN 27538). Centered on the XRT position, we calculate a 3-sigma limit of <4.5e-4 cts/s in the 0.5-8 keV energy range following the method described by Gehrels (1986) for small numbers of events. Applying the best-fit PC mode XRT spectral parameters (Gamma=1.7, intrinsic NH=1.5e21 cm^-2) and fixing the Galactic NH=1.55e20 cm^-2 (Willingale et al. 2013), we calculate a 3-sigma unabsorbed flux limit of FX<8.4e-15 erg/s/cm^2 in the 0.3-10 keV energy range.
The XRT afterglow starting from 200 sec post-burst exhibits a power-law decline with decay index alpha=-0.84 (+/- 0.2) (where FX~t^alpha), while the Chandra upper limit indicates a potential steepening to alpha<-1.3. If this steepening is interpreted as a jet break at ~0.5-2 days post-burst, using median values for the explosion properties and redshift based on properties of short GRBs gives an opening angle of ~4-7 degrees.
We thank the Chandra staff for the rapid planning and scheduling of these observations.”
photometric redshift z = 0.82 +0.17 -0.19
of host-galaxy: A. E. Nugent et al. 2022, ApJ, 940, 57
photometric redshift z= 0.6 +- 0.1
of host galaxy B. O'Connor et al. 2022, MN 515, 4890

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