Gamma-ray Burst 100424A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:33:58 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     420367,   Seg_Num: 0
GRB_RA:          209.453d {+13h 57m 49s} (J2000),
                 209.585d {+13h 58m 20s} (current),
                 208.817d {+13h 55m 16s} (1950)
GRB_DEC:          +1.513d {+01d 30' 48"} (J2000),
                  +1.463d {+01d 27' 48"} (current),
                  +1.757d {+01d 45' 24"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=2020 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        15310 TJD;   114 DOY;   10/04/24
GRB_TIME:        59562.26 SOD {16:32:42.26} UT
GRB_PHI:          75.56 [deg]
GRB_THETA:        12.51 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    10.47 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +0  +0  +0 +96  +0 
SUN_POSTN:        32.13d {+02h 08m 30s}  +12.98d {+12d 58' 56"}
SUN_DIST:        165.34 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.03d {+10h 52m 06s}   +2.49d {+02d 29' 35"}
MOON_DIST:        46.54 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.84 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      206.84, 12.69 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
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 = 72.23,-15.29 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:35:22 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     420367,   Seg_Num: 0
GRB_RA:          209.4467d {+13h 57m 47.2s} (J2000),
                 209.5781d {+13h 58m 18.7s} (current),
                 208.8101d {+13h 55m 14.4s} (1950)
GRB_DEC:          +1.5366d {+01d 32' 11.7"} (J2000),
                  +1.4866d {+01d 29' 11.9"} (current),
                  +1.7798d {+01d 46' 47.2"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       61 [cnts]
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59682.11 SOD {16:34:42.11} UT,   119.8 [sec] since BAT Trigger Time
CENTROID_X:      276.10,  raw= 276  [pixels]
CENTROID_Y:      296.29,  raw= 296  [pixels]
ROLL:            349.72 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -4.01
GRB_POS_XRT_Z:   -61.75
IMAGE_URL:       sw00420367000msxps_rw.img
SUN_POSTN:        32.13d {+02h 08m 30s}  +12.98d {+12d 58' 57"}
SUN_DIST:        165.31 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.04d {+10h 52m 09s}   +2.49d {+02d 29' 13"}
MOON_DIST:        46.52 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.58, 59.87 [deg] galactic lon,lat of the burst
ECL_COORDS:      206.83, 12.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:35:12 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     420367,   Seg_Num: 0
GRB_RA:          209.4467d {+13h 57m 47.20s} (J2000),
                 209.5781d {+13h 58m 18.73s} (current),
                 208.8101d {+13h 55m 14.42s} (1950)
GRB_DEC:          +1.5366d {+01d 32' 11.7"} (J2000),
                  +1.4866d {+01d 29' 11.9"} (current),
                  +1.7798d {+01d 46' 47.2"} (1950)
GRB_ERROR:       5.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.09e-09 [erg/cm2/sec]
GRB_SIGNIF:      7.81 [sigma]
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59682.11 SOD {16:34:42.11} UT,   119.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.69 237.23 261.58 243.63
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        32.13d {+02h 08m 30s}  +12.98d {+12d 58' 57"}
SUN_DIST:        165.31 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.04d {+10h 52m 09s}   +2.49d {+02d 29' 16"}
MOON_DIST:        46.52 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.58, 59.87 [deg] galactic lon,lat of the burst
ECL_COORDS:      206.83, 12.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.45 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:35:28 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     420367,   Seg_Num: 0
GRB_RA:          209.4467d {+13h 57m 47.2s} (J2000),
                 209.5781d {+13h 58m 18.7s} (current),
                 208.8101d {+13h 55m 14.4s} (1950)
GRB_DEC:          +1.5366d {+01d 32' 11.7"} (J2000),
                  +1.4866d {+01d 29' 11.9"} (current),
                  +1.7798d {+01d 46' 47.2"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       61 [cnts]
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59682.11 SOD {16:34:42.11} UT,   119.8 [sec] since BAT Trigger Time
CENTROID_X:      276.10,  raw= 276  [pixels]
CENTROID_Y:      296.29,  raw= 296  [pixels]
ROLL:            349.72 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -4.01
GRB_POS_XRT_Z:   -61.75
IMAGE_URL:       sw00420367000msxps_rw.img
SUN_POSTN:        32.13d {+02h 08m 30s}  +12.98d {+12d 58' 57"}
SUN_DIST:        165.31 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.04d {+10h 52m 09s}   +2.49d {+02d 29' 12"}
MOON_DIST:        46.52 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.58, 59.87 [deg] galactic lon,lat of the burst
ECL_COORDS:      206.83, 12.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:36:40 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     420367,   Seg_Num: 0
GRB_RA:          209.453d {+13h 57m 49s} (J2000),
                 209.585d {+13h 58m 20s} (current),
                 208.817d {+13h 55m 16s} (1950)
GRB_DEC:          +1.513d {+01d 30' 48"} (J2000),
                  +1.463d {+01d 27' 48"} (current),
                  +1.757d {+01d 45' 24"} (1950)
GRB_DATE:        15310 TJD;   114 DOY;   10/04/24
GRB_TIME:        59562.26 SOD {16:32:42.26} UT
TRIGGER_INDEX:   20000
GRB_PHI:          75.56 [deg]
GRB_THETA:        12.51 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    10.47 [sigma]
LC_URL:          sw00420367000msb.lc
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 58' 58"}
SUN_DIST:        165.34 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.05d {+10h 52m 12s}   +2.48d {+02d 28' 54"}
MOON_DIST:        46.52 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.84 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      206.84, 12.69 [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 an image 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 = 72.23,-15.29 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:37:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.449d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.519d {+01d 31' 09"} (J2000)
POINT_ROLL:      349.718d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59690.53 SOD {16:34:50.53} UT,   128.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.680
N_STARS:         24
X_OFFSET:        440 [pixels]
Y_OFFSET:        608 [pixels]
X_MAX:           1399 [pixels]
Y_MAX:           1567 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0128.fits
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 58' 59"}
SUN_DIST:        165.33 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.06d {+10h 52m 14s}   +2.48d {+02d 28' 39"}
MOON_DIST:        46.50 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:37:51 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.449d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.519d {+01d 31' 09"} (J2000)
POINT_ROLL:      349.718d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59690.53 SOD {16:34:50.53} UT,   128.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.680
N_STARS:         24
X_OFFSET:        440 [pixels]
Y_OFFSET:        608 [pixels]
X_MAX:           1399 [pixels]
Y_MAX:           1567 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0128.fits
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 58' 59"}
SUN_DIST:        165.33 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.06d {+10h 52m 15s}   +2.48d {+02d 28' 36"}
MOON_DIST:        46.50 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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.  
COMMENTS:        The uvot_field_srclist.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:37:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.449d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.519d {+01d 31' 09"} (J2000)
POINT_ROLL:      349.718d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59690.53 SOD {16:34:50.53} UT,   128.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.680
N_STARS:         24
X_OFFSET:        440 [pixels]
Y_OFFSET:        608 [pixels]
X_MAX:           1399 [pixels]
Y_MAX:           1567 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0128.fits
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 58' 59"}
SUN_DIST:        165.33 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.06d {+10h 52m 14s}   +2.48d {+02d 28' 39"}
MOON_DIST:        46.50 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:37:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.449d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.519d {+01d 31' 09"} (J2000)
POINT_ROLL:      349.718d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59690.53 SOD {16:34:50.53} UT,   128.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.680
N_STARS:         24
X_OFFSET:        440 [pixels]
Y_OFFSET:        608 [pixels]
X_MAX:           1399 [pixels]
Y_MAX:           1567 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0128.fits
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 58' 59"}
SUN_DIST:        165.33 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.06d {+10h 52m 14s}   +2.48d {+02d 28' 39"}
MOON_DIST:        46.50 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:39:20 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.449d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.519d {+01d 31' 09"} (J2000)
ROLL:            349.718d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59690.53 SOD {16:34:50.53} UT,   128.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     293819696
X_OFFSET:        901 [pixels]
Y_OFFSET:        831 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1061
Y_GRB_POS:       991
BINNING_INDEX:   1
IM_URL:          sw00420367000msuni0134.fits
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 59' 00"}
SUN_DIST:        165.33 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.07d {+10h 52m 18s}   +2.47d {+02d 28' 13"}
MOON_DIST:        46.49 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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:     Sat 24 Apr 10 16:39:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.449d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.519d {+01d 31' 09"} (J2000)
ROLL:            349.718d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59690.53 SOD {16:34:50.53} UT,   128.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     293819696
X_OFFSET:        901 [pixels]
Y_OFFSET:        831 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1061
Y_GRB_POS:       991
BINNING_INDEX:   1
IM_URL:          sw00420367000msuni0134.fits
SUN_POSTN:        32.13d {+02h 08m 31s}  +12.98d {+12d 59' 00"}
SUN_DIST:        165.33 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.08d {+10h 52m 18s}   +2.47d {+02d 28' 09"}
MOON_DIST:        46.48 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.  
COMMENTS:        The uvot_field_image.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:44:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59849.76 SOD {16:37:29.76} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.708
N_STARS:         66
X_OFFSET:        581 [pixels]
Y_OFFSET:        511 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1470 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00420367000msufc0287.fits
SUN_POSTN:        32.13d {+02h 08m 32s}  +12.98d {+12d 59' 04"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.12d {+10h 52m 28s}   +2.45d {+02d 27' 02"}
MOON_DIST:        46.44 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:44:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59849.76 SOD {16:37:29.76} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.708
N_STARS:         66
X_OFFSET:        581 [pixels]
Y_OFFSET:        511 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1470 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00420367000msufc0287.fits
SUN_POSTN:        32.13d {+02h 08m 32s}  +12.98d {+12d 59' 04"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.12d {+10h 52m 28s}   +2.45d {+02d 27' 02"}
MOON_DIST:        46.44 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:44:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59849.76 SOD {16:37:29.76} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.708
N_STARS:         66
X_OFFSET:        581 [pixels]
Y_OFFSET:        511 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1470 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00420367000msufc0287.fits
SUN_POSTN:        32.13d {+02h 08m 32s}  +12.98d {+12d 59' 04"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.12d {+10h 52m 28s}   +2.45d {+02d 27' 02"}
MOON_DIST:        46.44 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:44:12 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59849.76 SOD {16:37:29.76} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.708
N_STARS:         66
X_OFFSET:        581 [pixels]
Y_OFFSET:        511 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1470 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00420367000msufc0287.fits
SUN_POSTN:        32.13d {+02h 08m 32s}  +12.98d {+12d 59' 04"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.12d {+10h 52m 29s}   +2.45d {+02d 26' 59"}
MOON_DIST:        46.44 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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.  
COMMENTS:        The uvot_field_srclist.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:45:21 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
ROLL:            349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59849.76 SOD {16:37:29.76} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     293819855
X_OFFSET:        901 [pixels]
Y_OFFSET:        831 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1061
Y_GRB_POS:       991
BINNING_INDEX:   1
IM_URL:          sw00420367000msuni0293.fits
SUN_POSTN:        32.13d {+02h 08m 32s}  +12.98d {+12d 59' 05"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.13d {+10h 52m 31s}   +2.44d {+02d 26' 41"}
MOON_DIST:        46.43 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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 Circular #10667
E. A. Hoversten (PSU), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), W.B Landsman (GSFC), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), C. Pagani (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and M. A. Stark (PSU) report on behalf of the Swift Team:
At 16:32:42 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100424A (trigger=420367). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 209.453, +1.513 which is
```
   RA(J2000)  =  13h 57m 49s
   Dec(J2000) = +01d 30' 48"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT lightcurve shows nothing as is usual for an image trigger.
The XRT began observing the field at 16:34:42.1 UT, 119.8 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 209.4467, +1.5366 which is equivalent to:
```
   RA(J2000)  = 13h 57m 47.20s
   Dec(J2000) = +01d 32' 11.7"
```
with an uncertainty of 5.1 arcseconds (radius, 90% containment). No event data are yet available to determine the column density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 2.09e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 128 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03.
Burst Advocate for this burst is E. A. Hoversten (hoversten AT astro.psu.edu). 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/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:45:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
ROLL:            349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  59849.76 SOD {16:37:29.76} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     293819855
X_OFFSET:        901 [pixels]
Y_OFFSET:        831 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1061
Y_GRB_POS:       991
BINNING_INDEX:   1
IM_URL:          sw00420367000msuni0293.fits
SUN_POSTN:        32.13d {+02h 08m 32s}  +12.98d {+12d 59' 05"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.13d {+10h 52m 32s}   +2.44d {+02d 26' 38"}
MOON_DIST:        46.43 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.  
COMMENTS:        The uvot_field_image.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:51:29 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60427.53 SOD {16:47:07.53} UT,   865.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.506
N_STARS:         62
X_OFFSET:        341 [pixels]
Y_OFFSET:        271 [pixels]
X_MAX:           1780 [pixels]
Y_MAX:           1710 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0865.fits
SUN_POSTN:        32.14d {+02h 08m 33s}  +12.99d {+12d 59' 10"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.19d {+10h 52m 44s}   +2.42d {+02d 25' 08"}
MOON_DIST:        46.38 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:51:29 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60427.53 SOD {16:47:07.53} UT,   865.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.506
N_STARS:         62
X_OFFSET:        341 [pixels]
Y_OFFSET:        271 [pixels]
X_MAX:           1780 [pixels]
Y_MAX:           1710 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0865.fits
SUN_POSTN:        32.14d {+02h 08m 33s}  +12.99d {+12d 59' 10"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.19d {+10h 52m 44s}   +2.42d {+02d 25' 08"}
MOON_DIST:        46.38 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:51:29 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60427.53 SOD {16:47:07.53} UT,   865.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.506
N_STARS:         62
X_OFFSET:        341 [pixels]
Y_OFFSET:        271 [pixels]
X_MAX:           1780 [pixels]
Y_MAX:           1710 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0865.fits
SUN_POSTN:        32.14d {+02h 08m 33s}  +12.99d {+12d 59' 10"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.19d {+10h 52m 44s}   +2.42d {+02d 25' 08"}
MOON_DIST:        46.38 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:51:43 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
POINT_ROLL:      349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60427.53 SOD {16:47:07.53} UT,   865.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.506
N_STARS:         62
X_OFFSET:        341 [pixels]
Y_OFFSET:        271 [pixels]
X_MAX:           1780 [pixels]
Y_MAX:           1710 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00420367000msufc0865.fits
SUN_POSTN:        32.14d {+02h 08m 33s}  +12.99d {+12d 59' 10"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.19d {+10h 52m 45s}   +2.42d {+02d 25' 05"}
MOON_DIST:        46.37 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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.  
COMMENTS:        The uvot_field_srclist.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 16:53:00 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
ROLL:            349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60427.53 SOD {16:47:07.53} UT,   865.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     293820433
X_OFFSET:        900 [pixels]
Y_OFFSET:        830 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1060
Y_GRB_POS:       990
BINNING_INDEX:   1
IM_URL:          sw00420367000msuni0871.fits
SUN_POSTN:        32.14d {+02h 08m 33s}  +12.99d {+12d 59' 11"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.20d {+10h 52m 48s}   +2.41d {+02d 24' 45"}
MOON_DIST:        46.36 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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:     Sat 24 Apr 10 16:53:12 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     420367,   Seg_Num: 0
POINT_RA:        209.448d {+13h 57m 48s} (J2000)
POINT_DEC:        +1.521d {+01d 31' 16"} (J2000)
ROLL:            349.716d
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60427.53 SOD {16:47:07.53} UT,   865.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     293820433
X_OFFSET:        900 [pixels]
Y_OFFSET:        830 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1060
Y_GRB_POS:       990
BINNING_INDEX:   1
IM_URL:          sw00420367000msuni0871.fits
SUN_POSTN:        32.14d {+02h 08m 33s}  +12.99d {+12d 59' 11"}
SUN_DIST:        165.32 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.20d {+10h 52m 48s}   +2.41d {+02d 24' 42"}
MOON_DIST:        46.36 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.56, 59.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      206.83, 12.70 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.  
COMMENTS:        The uvot_field_image.ps.gz file does not exist; skipping the attachment.

GCN Circular #10668
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using 1.4 ks of promptly downlinked XRT data and 1 promptly available UVOT image we find an enhanced position of the XRT afterglow of GRB 100424A (Hoversten et al., GCN Circ. 10667) of RA, Dec 209.4478, 1.5386 which is equivalent to:
```
   RA(J2000)  = 13h 57m 47.44s
   Dec(J2000) = +01d 32' 18.8"
```
with an uncertainty of 2.0 arcseconds (radius, 90% containment). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/420367.
Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Apr 10 17:17:38 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     420367,   Seg_Num: 0
GRB_RA:          209.4478d {+13h 57m 47.47s} (J2000),
                 209.5792d {+13h 58m 19.00s} (current),
                 208.8112d {+13h 55m 14.68s} (1950)
GRB_DEC:          +1.5384d {+01d 32' 18.2"} (J2000),
                  +1.4884d {+01d 29' 18.3"} (current),
                  +1.7816d {+01d 46' 53.7"} (1950)
GRB_ERROR:       2.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15310 TJD;   114 DOY;   10/04/24
IMG_START_TIME:  60202.00 SOD {16:43:22.00} UT,   639.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        32.15d {+02h 08m 37s}  +12.99d {+12d 59' 32"}
SUN_DIST:        165.30 [deg]   Sun_angle= -11.8 [hr] (East of Sun)
MOON_POSTN:      163.42d {+10h 53m 41s}   +2.31d {+02d 18' 30"}
MOON_DIST:        46.14 [deg]
MOON_ILLUM:      82 [%]
GAL_COORDS:      337.58, 59.87 [deg] galactic lon,lat of the burst
ECL_COORDS:      206.83, 12.72 [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 Circular #10669
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1406 s of XRT Photon Counting mode data and 1 UVOT images for GRB 100424A, 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 = 209.44775, +1.53897 which is equivalent to:
```
RA (J2000): 13h 57m 47.46s
Dec (J2000): +01d 32' 20.3"
```
with an uncertainty of 1.7 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 #10670
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), E. A. Hoversten (PSU), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100424A (trigger #420367) (Hoversten et al., GCN Circ. 10667). The BAT ground-calculated position is RA, Dec = 209.453, 1.512 deg which is
```
    RA(J2000)  =  13h 57m 48.6s
    Dec(J2000) = +01d 30' 44.2"
```
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 88%.
The mask-weighted lightcurve shows a single broad peak from about T+20 to T+150 sec. T90 (15-350 keV) is 104 +- 15.5 sec (estimated error including systematics).
The time-averaged spectrum from T+22.3 to T+148.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.83 +- 0.13. The fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+58.28 sec in the 15-150 keV band is 0.4 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/420367/BA/
GCN Circular #10671
D. Malesani (DARK/NBI), D. Xu (Weizmann Inst.), A. J. Levan (Univ. Warwick), P. Jakobsson (Univ. Iceland), T. Pursimo (NOT), report on behalf of a larger collaboration:
We observed the field of GRB 100424A (Hoversten et al., GCN 10667) with the NOT equipped with ALFOSC in the R, I, and z filters. Observations started on April 24 at 22:38, 23:05, and 23:31 UT in R, I, z, respectively (6.30, 6.74, and 7.21 hr after the GRB), and were affected by the closeby bright Moon (42 deg away, 85% full) and some clouds.
We do not detect any new object within the refined XRT error circle (Evans, GCN 10668; Evans et al., GCN 10669). The limiting magnitudes are R(Vega) = 22.5 and z(AB) = 21.9, calibrated against the USNO-B1 and SDSS catalogs, respectively.
Given the relatively large X-ray flux, we encourage NIR observations.
GCN Circular #10672
A.J. Levan, C. Copperwheat, E. Breedt (U. Warwick), D. Malesani (DARK/NBI) report on behalf of a larger collaboration:
"We observed the localization of GRB 100424A (Hoversten et al. GCN 10667) using the WHT and ACAM. Observations begin at April 25 00:18, approximately 9 hours after the burst. We obtained 4x200s exposures in the z-band. No source is visible within the enhanced XRT location (Evans et al. GCN 10669) to a limiting magnitude of z>23.2, calibrated against SDSS.
The deep z-band limit, coupled with apparently bright early X-ray afterglow is suggestive of either a highly extinguished, or high redshift burst."
GCN Circular #10674
M. C. Stroh, D. Grupe and E. A. Hoversten (PSU) report on behalf of the Swift-XRT team:
We have analysed 641 s of XRT data for GRB 100424A (Hoversten et al. GCN Circ. 10667), from 126 s to 769 s after the BAT trigger. The data comprise 509 s in Windowed Timing (WT) mode 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=0.63 (+/-0.14). At T+288 s the decay steepens to an alpha of 1.41 (+0.27, -0.19) before breaking again at T+526 s to a final decay with index alpha=2.8 (+0.9, -0.6).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.26 (+/-0.06). The best-fitting absorption column is 1.62 (+0.22, -0.21) x 10^21 cm^-2, in excess of the Galactic value of 2.3 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.8 x 10^-11 (6.5 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 2.8, the count rate at T+24 hours will be 5.1 x 10^-6 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.0 x 10^-16 (3.3 x 10^-16) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00420367.
This circular is an official product of the Swift-XRT team.
GCN Circular #10675
A. N. Morgan and J. S. Bloom (UC Berkeley) report:
We observed the field of GRB 100424A (Hoversten et al., GCN 10667) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2010-04-25 03:51:19 UT, ~11.3 hours after the Swift Trigger, under high airmass. In mosaics (effective exposure time of 0.74 hours) taken simultaneously in the J, H, and Ks filters, we do not detect any source within the enhanced XRT error circle (Evans et al., GCN 10669).
The preliminary photometry yields:
```
post burst
t_mid (hr) exp.(hr) filt  U. Limit (3 sig)
11.81      0.74     J     > 19.3
11.81      0.74     H     > 18.4
11.81      0.74     Ks    > 17.0
```
Further observations are ongoing to obtain a deeper limit. All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values.
GCN Circular #10676
F. Olivares, T. Kruehler and J. Greiner (all MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 100424A (Swift trigger 420367; Hoversten et al., GCN 10667) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile).
Observations started at 00:16 UT on April 25, 7.7 hours after the GRB trigger, and continued for 3 hours. The observations were severely affected by passing cirrus clouds.
In our first stacked images of 24 min total integration time in g'r'i'z' and 20 min in JHK, we do not (see also Malesani et al., GCN 10671, Levan et al., GCN 10672, Morgan & Bloom GCN 10675) detect a source within the enhanced Swift/XRT error circle (Evans et al., GCN 10669) down to the following preliminary 3 sigma limiting magnitudes (all in the AB system):
```
g' > 23.03
r' > 23.37
i' > 22.96
z' > 23.04
J > 21.77
H > 21.21
K > 20.29
```
Later images do not increase these limiting magnitudes due to worse sky conditions. These limits were derived by calibrating the images against SDSS/2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #10677
K.Y. Huang (ASIAA), Y. Urata, P. Tsai (NCU) on behalf of EAFON report;
We observed the field of GRB 100424A (Hoversten et al., GCN 10667) in r' and z'-band with the LOT. Observations started at 17:52 UT on April 24, ~80 min after the Swift Trigger. In our z'-band stacked image shows no new object within the enhanced Swift/XRT position (Evans et al., GCN 10669) down to the following preliminary limiting magnitudes,
```
----------------------------
Time(hr)  Filter   Limit(AB)
----------------------------
2.16      z'       20.6
----------------------------
```
GCN Circular #10679
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 100424A (Hoversten et al. GCNC 10667) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2010-04-24 16:34:56 UT (~2.2 min after the burst). We did not find any new point source within the XRT error circle (Evans, GCNC 10668; Evans et al., GCNC 10669) in all the three bands.
Three sigma upper limits of the OT are listed below. We used SDSS catalog for flux calibration.
```
T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.00527    16:40:18   540.0     >18.4  >18.5  >17.7
0.04356    17:35:26  5940.0     >19.6  >20.0  >19.4
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
```
GCN Circular #10681
Jan Strobl (1), Martin Jelinek (2), Cyril Polasek (1), Petr Kubanek (2,3), Martin Nekola (1), Matus Kocka (1), Michal Jakubec (1) and Rene Hudec (1) (1. ASU AVCR Ondrejov, 2. IAA Granada, 3. GACE Valencia)
We observed the field of Swift GRB 100424A (Hoversten et al., GCNC 10667) with the 0.5m telescope D50 in Ondrejov (Czech Republic), starting at 23:27:02 UT, i.e. 06:54:20 after the trigger. A sequence of 20s unfiltered images was obtained. We coadded 60x20s exposure, obtaining an image with a limitting magnitude Rc~19.3, with an effective exposure time 7.35h after the trigger (23:54UT). We do not detect any new source within the XRT localization (Evans et al., GCN10699).
This message can be cited.
GCN Circular #10682
S. B. Cenko, J. S. Bloom, A. N. Morgan, and B. E. Cobb (UC Berkeley) report on behalf of a larger collaboration:
We have imaged the field of GRB 100424A (Hoversten et al., GCN 10667) with the Near-InfraRed Imager and Spectrometer mounted on the 8 m Gemini North telescope. Observations were taken in the J and K filters beginning at 6:28 UT on 25 April 2010 (~ 14 hours after the burst).
At the edge of the refined XRT error circle (Evans et al., GCN 10669) we identify a faint point source in both filters. Referencing both the astrometry and photometry to the 2MASS source 13574681+0131477, we measure a position (J2000.0) of
RA: 13:57:47.43 Dec: +01:32:18.9
and approximate magnitudes of K = 19.9, J = 22.1 (both Vega magnitudes). The J-K color indicates a red afterglow, though does not necessarily require a high-redshift origin (e.g., Levan et al., GCN 10672). No other objects are detected inside the XRT error circle.
Without evidence for variability, we cannot definitively confirm if this source is the afterglow of GRB 100424A. Further observations are planned to search for fading.
We wish to thank the staff at Gemini Observatory, in particular Kristin Chiboucas, for promptly executing these observations.
GCN Circular #10687
Z. Cano, A. Melandri (Liverpool JMU), C. Guidorzi (U. Ferrara), C. Mundell, R.J. Smith, D. Bersier, I.A. Steele, S. Kobayashi, C.J. Mottram, (Liverpool JMU), A. Gomboc (U. Ljubljana) report, on behalf of a larger collaboration:
We observed the field of GRB 100424A (Hoversten et al. GCNC 10667) with the Liverpool Telescope starting 20:54 UT on April 24, 2010. We do not detect the NIR afterglow discovered by Cenko et al. (GCN 10682), nor any other object within the enhanced XRT error circle (Evans, GCN 10668; Evans et al., GCN 10669) down to the following limits:
```
-------------------------------------------------------------------
 Mid Exposure        Total
  T-To (hrs)   Exposure Time (min)     Filter          upper limit
-------------------------------------------------------------------
     6.91              30                 B              >21.5
     6.92              50                 I              >21.8
     8.38              20                 R              >21.7
-------------------------------------------------------------------
```
The upper limits are for an isolated object in our images and are calibrated using nearby stars in the USNO-B1 catalogue. No correction for Galactic extinction has been made.
GCN Circular #10688
P.A. Curran (MSSL-UCL) and E. Hoversten (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 100424A 128 s after the BAT trigger (Hoversten et al., GCN Circ. 10667). No optical afterglow consistent with the refined XRT position (Evans et al., GCN Circ. 10669) or the proposed NIR counterpart (Cenko et al. (GCN Circ. 10682) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the initial finding charts (FC) and exposures are:
```
Filter   T_start(s) T_stop(s)   Exp(s)   Mag
----------------------------------------------
white    128         278        147      >20.8 (FC)
u        288         537        246      >20.0 (FC)
white    128        2046        444      >21.2
v        618        1930        156      >19.2
b        543        2028        156      >20.1
u        288        2003        382      >20.1
w1       668        1979        156      >19.7
m2       642        1955         97      >19.1
w2       594        5584        193      >20.0
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.08 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #10690
S. B. Cenko, A. N. Morgan, and J. S. Bloom (UC Berkeley) report on behalf of a larger collaboration:
We have obtained further imaging of the field of GRB 100424A (Hoversten et al., GCN 10667) with the Near InfraRed Imager and Spectrometer mounted on the 8 m Gemini North telescope. Following our report of a detection of a candidate afterglow in the J and K filters (Cenko et al., GCN 10682), we obtained a sequence of H-band images beginning at 9:29 UT on 25 April 2010 (~ 17 hours after the burst).
The candidate afterglow is also detected in the H-band. Using the PAIRITEL imaging of the field for photometric calibration (Morgan and Bloom, GCN 10675), we measure a magnitude of H = 20.9 (Vega) at this time.
Combined with our previous J and K photometry (and assuming the afterglow decays in time like a power-law with index alpha=-1), the candidate infrared afterglow appears consistent with a relatively steep spectral power-law index of beta ~ 2.5-3.0 across all three bands. This suggests the afterglow is reddened due predominantly to dust in the host galaxy of the GRB, and not an extremely high-redshift (z > 7) origin, as would be suggested by the presence of host galaxy extinction from the X-ray afterglow spectrum (Stroh et al., GCN 10674).
We wish to thank the staff at Gemini Observatory for assistance in executing these observations.
GCN Circular #10692
S. B. Cenko, J. S. Bloom, D. A. Perley, A. N. Morgan, B. E. Cobb (UC Berkeley) and A. J. Levan (U. Warwick) report on behalf of a larger collaboration:
We have obtained a second epoch of K-band imaging of the field of GRB 100424A (Hoversten et al., GCN 10667) with the Near InfraRed Imager and Spectrometer mounted on the 8 m Gemini North telescope. Observations began at 11:23 UT on 26 April 2010 (~ 43 hours after the burst).
The previously identified candidate in the XRT error circle (Cenko et al., GCN 10682) has faded by 0.9 +/- 0.1 mag, confirming the object is indeed the NIR afterglow of GRB 100424A. Assuming negligible contribution from an underlying host galaxy, the inferred power-law decay index, alpha ~ 0.7, is relatively shallow.
We wish to thank the staff at Gemini Observatory, in particular Kristin Chiboucas, for executing these observations.
GCN Circular #10693
V. Rumyantsev, D. Shakhovskoy (CrAO), A. Volnova (SAI MSU), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 100424A (Hoversten et al., GCN 10667) with AZT-11 telescope of CrAO observatory between (UT) Apr. 24 18:01 - 19:18 under seeing of about 3 arcsec. We detected a probable source at coordinates (J2000) RA = 13:57:47.64 Dec = +01:32:21.06 with an uncertainty of 0.5 arcsec in both coordinates. The probable source is located 2.8 arcsec from the enhanced XRT position with an uncertainty (radius) of 1.7 arcsec (Evans et al., GCN 10669). Due to low S/N we cannot confirm the detected source is a real object.
We do not detect any source at the position of afterglow candidate (Cenko, et al., GCN 10682, Cenko, et al., GCN 10690).
The photometry of the probable source and upper limit of the point-like source in a stacked image based on USNO-B1.0 star (RA(J2000) = 13:57:45.54 Dec(J2000)= +01:33:29.7) and assuming R=17.80 is following:
```
T0+      Filter, Exposure, mag.           UL
(mid, d)         (s)

0.0882   R       21x180    20.1 +/- 0.3   20.4
```
The combined image can be found at http://grb.rssi.ru/GRB100424A/GRB100424a_R_AZT11.gif
GCN Circular #10701
Dale A. Frail (NRAO) and Poonam Chandra (RMC) report on behalf of a larger collaboration:
"We observed the localization of GRB 100424A (Hoversten et al. GCN 10667) the Expanded Very Large Array (EVLA) on April 27.14 UT at a center frequency of 8.46 GHz. We do not detect any radio source anywhere within the refined XRT error circle (Evans et al., GCN 10669) to a 3-sigma limit of 66 uJy.
The EVLA is still undergoing active commissioning and we caution that these results should be considered preliminary. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Report 280.1
GCN_Report 280.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_280_1.pdf by E.A. Hoverstem at PSU titled: "Final Swift Observations of GRB 100424A"
GCN Circular #14291
D. Malesani, D. Xu, J. P. U. Fynbo, T. Kruehler (DARK/NBI), D. A. Perley (Caltech), S. D. Vergani (CNRS/GEPI), P. Goldoni (APC/IRFU-CEA), report on behalf of the GRB GTO X-shooter collaboration:
We observed the field of GRB 100424A (Hoversten et al., GCN 10667) using the Keck-I telescope equipped with the LRIS instrument. Observations were carried out on 2010 July 8.2 UT (74.5 days after the burst), simultaneously in the g and I bands, for a total exposure time of 35 and 32 min, respectively.
Consistent with the position of the NIR afterglow (Cenko et al., GCNs 10682, 10690, 10692), we detected a source with g = 26 (AB) and I = 24.4 (Vega). We consider this object to be the host galaxy of GRB 100424A.
A spectrum of this source was taken on 2013 March 11.3 UT with the ESO VLT equipped with the X-shooter spectrograph, covering the wavelength range 3000-25000 AA. The exposure time was 8x600 s. In the NIR arm, we detect four emission lines, that we interpret as [O III](4959), [O III](5007), Hbeta, and [O II](3727), all at a common redshift of z = 2.465. In the UVB arm, we also detect weak Lyalpha in emission at the same redshift.
We acknowledge excellent support from the observing staff at Mauna Kea and Paranal, in particular Thomas Rivinius and Claudio Melo.

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Jochen Greiner, last update: 12-Mar-2013 [Disclaimer]