Gamma-ray Burst 070810B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:19:31 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     287409,   Seg_Num: 0
GRB_RA:            8.940d {+00h 35m 46s} (J2000),
                   9.039d {+00h 36m 09s} (current),
                   8.293d {+00h 33m 10s} (1950)
GRB_DEC:          +8.835d {+08d 50' 07"} (J2000),
                  +8.877d {+08d 52' 38"} (current),
                  +8.560d {+08d 33' 36"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       542 [cnts]    Image_Peak=56 [image_cnts]
TRIGGER_DUR:     0.064 [sec] 
TRIGGER_INDEX:   10418     E_range: 25-100 keV
BKG_INTEN:       33242 [cnts]
BKG_TIME:        55141.85 SOD {15:19:01.85} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14322 TJD;   222 DOY;   07/08/10
GRB_TIME:        55157.85 SOD {15:19:17.85} UT
GRB_PHI:         -151.53 [deg]
GRB_THETA:         7.95 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     15.39 [sigma]
IMAGE_SIGNIF:    6.79 [sigma]
MERIT_PARAMS:     +1  +0  +0  -4  +2  +4  +0  +0 +58  +1 
SUN_POSTN:       140.07d {+09h 20m 17s}  +15.55d {+15d 32' 57"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.22d {+07h 24m 54s}  +25.92d {+25d 54' 57"}
MOON_DIST:        96.90 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.36,-53.84 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       11.69,  4.58 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 119.55,13.32 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:20:30 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.848d {+08d 50' 53"} (J2000)
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55219.36 SOD {15:20:19.36} UT,   61.5 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:22:22 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.848d {+08d 50' 53"} (J2000)
POINT_ROLL:      63.483d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55222.83 SOD {15:20:22.83} UT,   65.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.672
N_STARS:         24
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0064.fits
SUN_POSTN:       140.07d {+09h 20m 18s}  +15.55d {+15d 32' 55"}
SUN_DIST:        125.69 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.25d {+07h 25m 01s}  +25.91d {+25d 54' 37"}
MOON_DIST:        96.91 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.82 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:22:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.848d {+08d 50' 53"} (J2000)
POINT_ROLL:      63.483d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55222.83 SOD {15:20:22.83} UT,   65.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.672
N_STARS:         24
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0064.fits
SUN_POSTN:       140.07d {+09h 20m 18s}  +15.55d {+15d 32' 55"}
SUN_DIST:        125.69 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.26d {+07h 25m 02s}  +25.91d {+25d 54' 34"}
MOON_DIST:        96.92 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.82 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:23:41 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.848d {+08d 50' 53"} (J2000)
ROLL:            63.483d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55222.83 SOD {15:20:22.83} UT,   65.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     208452024
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0064.fits
SUN_POSTN:       140.08d {+09h 20m 18s}  +15.55d {+15d 32' 54"}
SUN_DIST:        125.69 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.27d {+07h 25m 04s}  +25.91d {+25d 54' 28"}
MOON_DIST:        96.93 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.82 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:23:54 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     287409,   Seg_Num: 0
GRB_RA:            8.940d {+00h 35m 46s} (J2000),
                   9.039d {+00h 36m 09s} (current),
                   8.293d {+00h 33m 10s} (1950)
GRB_DEC:          +8.835d {+08d 50' 07"} (J2000),
                  +8.877d {+08d 52' 38"} (current),
                  +8.560d {+08d 33' 36"} (1950)
GRB_DATE:        14322 TJD;   222 DOY;   07/08/10
GRB_TIME:        55157.88 SOD {15:19:17.88} UT
TRIGGER_INDEX:   10418
GRB_PHI:         -151.53 [deg]
GRB_THETA:         7.95 [deg]
DELTA_TIME:      -2.00 [sec]
TRIGGER_DUR:     0.064 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     15.39 [sigma]
IMAGE_SIGNIF:    6.79 [sigma]
LC_URL:          sw00287409000msb.lc
SUN_POSTN:       140.08d {+09h 20m 18s}  +15.55d {+15d 32' 54"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.27d {+07h 25m 05s}  +25.91d {+25d 54' 26"}
MOON_DIST:        96.94 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.36,-53.84 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       11.69,  4.58 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 119.55,13.32 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:24:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.848d {+08d 50' 53"} (J2000)
ROLL:            63.483d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55222.83 SOD {15:20:22.83} UT,   65.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     208452024
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0064.fits
SUN_POSTN:       140.08d {+09h 20m 18s}  +15.55d {+15d 32' 54"}
SUN_DIST:        125.69 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.27d {+07h 25m 05s}  +25.91d {+25d 54' 25"}
MOON_DIST:        96.93 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.82 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:30:10 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 46"} (J2000)
POINT_ROLL:      63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55328.81 SOD {15:22:08.81} UT,   171.0 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.642
N_STARS:         45
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0170.fits
SUN_POSTN:       140.08d {+09h 20m 19s}  +15.55d {+15d 32' 50"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.33d {+07h 25m 20s}  +25.90d {+25d 53' 43"}
MOON_DIST:        96.99 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:31:03 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 46"} (J2000)
ROLL:            63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55328.81 SOD {15:22:08.81} UT,   171.0 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     208452130
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0170.fits
SUN_POSTN:       140.08d {+09h 20m 19s}  +15.55d {+15d 32' 49"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.34d {+07h 25m 22s}  +25.89d {+25d 53' 36"}
MOON_DIST:        97.00 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:31:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 46"} (J2000)
ROLL:            63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55328.81 SOD {15:22:08.81} UT,   171.0 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     208452130
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0170.fits
SUN_POSTN:       140.08d {+09h 20m 19s}  +15.55d {+15d 32' 49"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.35d {+07h 25m 23s}  +25.89d {+25d 53' 34"}
MOON_DIST:        97.00 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:35:38 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.948d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.845d {+08d 50' 44"} (J2000)
POINT_ROLL:      63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56019.50 SOD {15:33:39.50} UT,   861.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.737
N_STARS:         36
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0861.fits
SUN_POSTN:       140.08d {+09h 20m 20s}  +15.55d {+15d 32' 46"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.39d {+07h 25m 33s}  +25.88d {+25d 53' 04"}
MOON_DIST:        97.04 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:36:05 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.948d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.845d {+08d 50' 44"} (J2000)
POINT_ROLL:      63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56019.50 SOD {15:33:39.50} UT,   861.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.737
N_STARS:         36
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0861.fits
SUN_POSTN:       140.08d {+09h 20m 20s}  +15.55d {+15d 32' 45"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.39d {+07h 25m 34s}  +25.88d {+25d 53' 01"}
MOON_DIST:        97.04 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:37:00 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.948d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.845d {+08d 50' 44"} (J2000)
ROLL:            63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56019.50 SOD {15:33:39.50} UT,   861.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     208452821
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0861.fits
SUN_POSTN:       140.08d {+09h 20m 20s}  +15.55d {+15d 32' 45"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.40d {+07h 25m 37s}  +25.88d {+25d 52' 55"}
MOON_DIST:        97.05 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:37:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.948d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.845d {+08d 50' 44"} (J2000)
ROLL:            63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56019.50 SOD {15:33:39.50} UT,   861.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     208452821
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0861.fits
SUN_POSTN:       140.08d {+09h 20m 20s}  +15.55d {+15d 32' 44"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.41d {+07h 25m 37s}  +25.88d {+25d 52' 52"}
MOON_DIST:        97.06 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:42:24 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 45"} (J2000)
POINT_ROLL:      63.486d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56125.36 SOD {15:35:25.36} UT,   967.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.600
N_STARS:         37
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0967.fits
SUN_POSTN:       140.09d {+09h 20m 21s}  +15.54d {+15d 32' 41"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.46d {+07h 25m 50s}  +25.87d {+25d 52' 17"}
MOON_DIST:        97.10 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:42:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 45"} (J2000)
POINT_ROLL:      63.486d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56125.36 SOD {15:35:25.36} UT,   967.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.600
N_STARS:         37
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0967.fits
SUN_POSTN:       140.09d {+09h 20m 21s}  +15.54d {+15d 32' 40"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.46d {+07h 25m 51s}  +25.87d {+25d 52' 13"}
MOON_DIST:        97.11 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:43:43 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 45"} (J2000)
ROLL:            63.486d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56125.36 SOD {15:35:25.36} UT,   967.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     208452927
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0967.fits
SUN_POSTN:       140.09d {+09h 20m 21s}  +15.54d {+15d 32' 40"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.47d {+07h 25m 53s}  +25.87d {+25d 52' 08"}
MOON_DIST:        97.12 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:44:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 45"} (J2000)
ROLL:            63.486d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  56125.36 SOD {15:35:25.36} UT,   967.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     208452927
X_OFFSET:        752 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       912
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw00287409000msuni0967.fits
SUN_POSTN:       140.09d {+09h 20m 21s}  +15.54d {+15d 32' 39"}
SUN_DIST:        125.71 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.47d {+07h 25m 54s}  +25.87d {+25d 52' 05"}
MOON_DIST:        97.12 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 10 Aug 07 15:29:48 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     287409,   Seg_Num: 0
POINT_RA:          8.947d {+00h 35m 47s} (J2000)
POINT_DEC:        +8.846d {+08d 50' 46"} (J2000)
POINT_ROLL:      63.487d
IMG_START_DATE:  14322 TJD;   222 DOY;   07/08/10
IMG_START_TIME:  55328.81 SOD {15:22:08.81} UT,   171.0 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.642
N_STARS:         45
X_OFFSET:        433 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1392 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00287409000msufc0170.fits
SUN_POSTN:       140.08d {+09h 20m 19s}  +15.55d {+15d 32' 50"}
SUN_DIST:        125.70 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:      111.33d {+07h 25m 19s}  +25.90d {+25d 53' 45"}
MOON_DIST:        96.99 [deg]
MOON_ILLUM:      6 [%]
GAL_COORDS:      116.37,-53.83 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       11.70,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #6743
F. E. Marshall (NASA/GSFC), P. J. Brown (PSU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), C. Guidorzi (Univ Bicocca&INAF-OAB), S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU), V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD), J. P. Osborne (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), E. Troja (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and D. E. Vanden Berk (PSU) report on behalf of the Swift Team:
At 15:19:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 070810B (trigger=287409). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 8.940, +8.835 which is
```
   RA(J2000) = 00h 35m 46s
   Dec(J2000) = +08d 50' 07"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single short spike with a duration of < 0.2 sec. The peak count rate was ~4500 counts/sec (15-350 keV), at ~0 sec after the trigger. The lightcurves in different bands indicate an intermediate spectrum that is neither hard nor soft.
The XRT began taking data at 15:20:19 UT, 62 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image and we do not detect a source in the initial SPER images. However, it is possible that the source is very faint or lies outside the SPER window. We await down-linked data to detect and determine a position for the source.
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 65 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 18.5 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for extinction corresponding to the expected reddening of E(B-V)=0.05.
We note the presence of the bright extended galaxy 2MASX J00355339+0849273 (= LEDA 1354367) within the BAT error circle.
Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 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 Circular #6746
M. Uemura, A. Arai, O. Nagae, and T. Uehara (Hiroshima Univ.), report on behalf of the KANATA GRB team:
We started optical imaging of the field of GRB070810B (GCN 6743) at 15:22:37 UT 10 Aug. using TRISPEC attached to the KANATA 1.5-m telescope at Higashi-Hiroshima Observatory, Japan. Exposure times are 30 sec for the first 10 frames, then changed to 123 sec for late frames.
We have performed preliminary analysis for the first 30-min images. No new bright object was detected. There is no object showing significant fadings. Limit magnitudes are estimated from neighbour USNO A2.0 stars as follows:
```
10 Aug. UT  limit mag.  band
15:33:22    20.8        Rc
15:55:04    20.9        Rc
```
We note that there is a possible minor planet at RA=00:35:59.3, Dec=+08:50:15 (time=15:33:22 UT). The object is about Rc=20.1, and moving northward during our observations.
GCN Circular #6747
L.P. Xin, M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, Y. Urata, and W.K. Zheng on behalf of EAFON report:
We have imaged the field of GRB 070810B (Marshall et al., GCN 6743) with the Xinglong TNT 80cm telescope. Observation started from 15:24:17, 300s after the burst. A series of White and R band images were obtained. Preliminary analysis shows no new object was seen in our combined image within BAT error circle. The 3 sigam limit is ~20.5 in our co-added 20*20s White band image with mean time ~550s after the burst, and ~21.7 in co-added 11*360s R band image with mean time ~44 minutes after the burst derived from USNO-B1.0, Further analysis is on going.
This message may be cited.
GCN Circular #6753
T. Sakamoto (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. E. Marshall (GSFC), D. Palmer (LANL), A. Parsons (GSFC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+303 sec from recent telemetry downlinks, we report further analysis of BAT GRB 070810B (trigger #287409) (Marshall, et al., GCN Circ. 6743). The BAT ground-calculated position is RA, Dec = 8.952, 8.822 deg which is
```
    RA(J2000) = 0h 35m 48.4s
    Dec(J2000) = 8d 49' 18"
```
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The light curve is a single FRED-like peak starting at T+0, and ending at T+0.12 sec. T90 (15-350 keV) is 80 +- 10 msec (estimated error including systematics).
The time-averaged spectrum from T+0.008 to T+0.092 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.44 +- 0.37. The fluence in the 15-150 keV band is 1.2 +- 0.3 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.45 sec in the 15-150 keV band is 1.8 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #6754
R. Starling (U. Leicester), C. Markwardt (CRESST/GSFC/UMD) and F.E. Marshall (NASA/GSFC) report, on behalf of the Swift XRT team:
We have analysed 7.2 ks of Swift XRT photon counting mode data, beginning 70 s and ending 13.8 ks after the BAT trigger, for the short GRB 070810B (trigger=287409; Marshall et al., GCN Circ. 6743). We do not detect any X-ray sources at 3-sigma significance or greater within the refined BAT error circle (Sakamoto et al., GCN Circ. 6753).
Two low significance (2-sigma) possible sources are found within the BAT refined error circle at the following positions:
```
Source 1
RA (J2000)  =  00h 35m 51.2s 
Dec (J2000) = +08d 51' 21.3''

Source 2
RA (J2000)  =  00h 35m 50.0s
Dec (J2000) = +08d 48' 45.0''
```
Using the Bayesian method we find that both sources have between 4 and 26 counts at the 99% confidence level. It is not possible to determine at this stage whether or not either of these sources are fading.
We note that Source 2 lies 1.1 arcmin from the galaxy 2MASX J00355339+0849273 (= LEDA 1354367; RA, Dec (J2000) = 00h 35m 53.39s, +08d 49' 27.3''), which has angular diameter approximately 0.7 x 0.3 arcmin.
This is an official product of the Swift XRT team.
GCN Circular #6755
P.J. Brown and F.E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 070810B (trigger #287409) starting 65 s after the BAT trigger (Marshall et al., GCN Circ. 6743). We do not find any new source in the UVOT observations inside the refined BAT error circle (Sakamoto et al., GCN Circ. 6753) including the two low significance XRT sources (Starling et al., GCN Circ. 6754). The galaxy 2MASX J00355339+0849273 (= LEDA 1354367) is visible in all filters except uvm2, but does not show signs of variability. The 3-sigma upper limits for detecting a source in the first finding chart (FC) exposure and co-added frames are:
```
Filter       T_start(s)   T_stop(s)     Exp(s)     Mag (3-sigma UL)

white (FC)   66           165           98         >20.5
white        66           13134         1345       >22.0
v            172          7372          1296       >20.4
b            653          12222         1299       >21.2
u            628          7987          549        >20.3
uvw1         604          7782          549        >20.5
uvm2         579          7577          549        >20.4
uvw2         683          13859         1237       >21.1
```
The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V) = 0.053 mag towards the direction of the burst (Schlegel et al. 1998).
GCN Circular #6756
Christina C. Thoene (DARK, UC Berkeley), Joshua S. Bloom, Nathaniel R. Butler (UCB) and Peter Nugent (LBL) report:
We obtained spectra of several sources around the reported XRT positions of GRB70810B (GCN 6754 , Starling et al.) on Aug. 11, 12:30 UT, using Keck I + LRIS. No new source is seen in imaging of the field at the same time. At the position of source 1 ("S1") from Starling et al., there is no optical counterpart visible. From further analysis of the X-ray data, we detect another weak X-ray source at RA 00:35:46.892, DEC 08:51:05.96 ("S3") which includes a weak optical source. Within the BAT error circle, there is an early type galaxy (LEDA 1354367) as noted first in Marshall et. al, GCN 6743, for which we determined a redshift of z=0.0385 derived from Ca H&K absorption lines. Around source 2 ("S2"), there are four galaxies of which two show strong emission lines leading to a redshifts around z=0.49 from OII, OIII and the Balmer series. The two other galaxies have marginal detections of emission lines at the same redshift and these galaxies might therefore be part of a cluster or even interacting.
An image indicating the different XRT positions and galaxies observed can be found at: http://lyra.berkeley.edu/~cthoene/GRBs/GRB070810B.png
CT wants to thank Keck support astronomer Greg Wirth and his wife for excellent dinner support during the observations. Tusend tak!
GCN Circular #6758
C. Guidorzi (U. Bicocca/INAF-OAB), R.J. Smith, A. Melandri, I.A. Steele, C.G. Mundell, M.J. Burgdorf, C.J. Mottram, M.F. Bode, S.N. Fraser, S. Kobayashi, D.F. Bersier (Liverpool JMU), A. Gomboc (Ljubljana), P. O'Brien, E. Rol, N. Bannister, N. Tanvir (U. Leicester) report on behalf of larger GRB collaboration:
On 2007 Aug 10 at 15:22:06 UT the 2-m Faulkes Telescope South automatically observed the field of GRB 070810B (trigger 287409, Marshall et al., GCN Circ. 6743).
In our coadded frames we do not detect anything corresponding to XRT sources 1 or 2 (Starling et al., GCN Circ. 6754) down to the limiting magnitudes reported below.
```
Filter  Tstart(min)  Tstop(min)    Exposure(s)    M_lim
-------------------------------------------------------
    R       2.80          64.3          840         21.2
    i'      6.22          54.9          520         21.5
-------------------------------------------------------
```
Magnitudes are calibrated with respect to USNOB1 R2 in the R filter. For the SDSS-i' filter we calibrated with the i' magnitudes derived for USNOB1 field stars by converting from the (R2,I) magnitudes.
GCN Report 81.1
GCN_Report 81.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_81_1.pdf by F.E. Marshall at NASA/GSFC titled: "Swift Observations of GRB 070810B"
GCN Circular #6762
V. Rumyantsev (CrAO) , V.Biryukov (SAI, MSU and CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the error box of short GRB070810b (Marshall et al., GCN 6743) with Shajn 2.6m telescope of CrAO on Aug. 10. Series of images were obtained between (UT) 2007-08-10 22:05:23 and 2007-08-10 23:25:50 in R filter. The combined image of a total exposure of 4260 s (71x60 s) covers entire of the error box of GRB 070810b and can be found at http://grb.rssi.ru/GRB070810b/GRB070810b_ZTSh.gif. The limiting magnitude (3 sigma) calibrated against USNO-A2.0 of the combined image is 24.8 mag.
We investigate the S1, S2 XRT positions of GRB70810b (GCN 6754 , Starling et al.) and S3 position (Thoene et al., GCN 6756).
There is marginally detected object in a place of the source S1 (see http://grb.rssi.ru/GRB070810b/GRB070810b_s1_ZTSh.gif).
Both optical sources around S3 (RA = 00:35:46.892 Dec = +08:51:05.96) are presented in our and Keck's images, see http://grb.rssi.ru/GRB070810b/GRB070810b_s3_ZTSh.gif.
Comparison of objects around source S2 ( RA = 00h 35m 50.0s Dec = +08d 48' 45.0'' ) in our image ( see http://grb.rssi.ru/GRB070810b/GRB070810b_s2_ZTSh.gif) with the image obtained on Aug. 11 (Thoene et al., GCN 6756) reveals a source between two nearby galaxies. We consider this source as a candidate of the optical counterpart of GRB070810b and a redshift z~0.49 obtained for the galaxies (Thoene et al., CN 6756) is quite natural for short GRB detected by Swift. However more detailed comparison of the images (Keck I and ZTSh) and additional observations are necessary to secure the nature of the candidate.
The massage can be cited.
GCN Circular #6771
D. Kocevski, J.S. Bloom, C. C. Thoene, and J. Prochaska report:
We performed image subtraction between multiple R-band observations of the error box of short burst GRB070810b (Marshall et al., GCN 6743) with the Keck I telescope (+LRIS). The first epoch of observations began at (UT) 2007-08-11 14:45:00 followed by a second epoch six nights later at (UT) 2007-08-17 12:02:00, with equivalent exposures of 630 and 900 seconds respectively. Image subtraction using the public POIS-IPP package(*) software shows no variable sources associated with the S1, S2 XRT positions (GCN 6754 , Starling et al.) or the S3 position (Thoene et al., GCN 6756) nor any significant residual sources within the BAT error circle down to a limiting magnitude of ~25.5 mag in R band. The potential candidate afterglow close to S2, reported by Pozanenko et al. can be resolved as two objects in our images, which show no sign of variability between the two epochs.
* See http://pan-starrs.ifa.hawaii.edu/project/IPP/software/
GCN Circular #6852
R. Starling, J.P. Osborne, K.L. Page (U. Leicester) and F.E. Marshall (NASA/GSFC) report, on behalf of the Swift XRT team:
Previously, Swift XRT data for the short GRB 070810B (trigger=287409; Marshall et al., GCN Circ. 6743) up to 13.8 ks after the BAT trigger showed two possible sources within the BAT refined error circle, detected at 2-sigma significance in 7.2 ks and termed S1 and S2 (Starling et al., GCN Circ. 6754).
We have analysed a further 12.6 ks of Swift XRT photon counting mode data beginning 42 days and ending 54 days after the burst, in order to assess the variability of the two possible afterglow candidates.
In this second epoch of data we detect one X-ray source at 4-sigma significance within the refined BAT error circle (Sakamoto et al., GCN Circ. 6753), corresponding to the source S2 described in GCN Circ. 6754. Using Bayesian analysis we find that S2 has between 20 and 54 counts at the 99% confidence level or 1.6e-3 to 4.3e-3 count/s, consistent with the first epoch limits of 5.6e-4 to 3.6e-3 count/s. This suggests that S2 is a persistent faint source, and not the afterglow of GRB 070810B.
The possible source S1 (GCN Circ. 6754), detected only at the 2-sigma level in the intial epoch observations, is not detected in the second epoch observations, providing an upper limit on the count rate of 6.7e-4 count/s at 99% confidence based on the background count rate. This is above the 3-sigma lower limit on the source count rate at epoch 1 of 5.6e-4 count/s, hence we cannot determine whether or not this source has faded.
This is an official product of the Swift XRT team.

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Jochen Greiner, last update: 05-Oct-2007 [Disclaimer]