Gamma-ray Burst 080810

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:10:27 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     319584,   Seg_Num: 0
GRB_RA:          356.779d {+23h 47m 07s} (J2000),
                 356.890d {+23h 47m 34s} (current),
                 356.139d {+23h 44m 33s} (1950)
GRB_DEC:          +0.320d {+00d 19' 11"} (J2000),
                  +0.368d {+00d 22' 03"} (current),
                  +0.042d {+00d 02' 31"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5019 [cnts]    Image_Peak=196 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       31443 [cnts]
BKG_TIME:        47396.99 SOD {13:09:56.99} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14688 TJD;   223 DOY;   08/08/10
GRB_TIME:        47412.28 SOD {13:10:12.28} UT
GRB_PHI:          63.98 [deg]
GRB_THETA:        20.44 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     14.73 [sigma]
IMAGE_SIGNIF:    7.59 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +3  +0  +0 +78  +1 
SUN_POSTN:       140.71d {+09h 22m 49s}  +15.35d {+15d 21' 10"}
SUN_DIST:        140.95 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.27d {+16h 17m 04s}  -26.46d {-26d 27' 28"}
MOON_DIST:       110.32 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.92,-58.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      357.17,  1.57 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 246.16,-15.75 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:12:21 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     319584,   Seg_Num: 0
GRB_RA:          356.7936d {+23h 47m 10.4s} (J2000),
                 356.9039d {+23h 47m 36.9s} (current),
                 356.1531d {+23h 44m 36.7s} (1950)
GRB_DEC:          +0.3188d {+00d 19' 07.6"} (J2000),
                  +0.3667d {+00d 21' 59.9"} (current),
                  +0.0409d {+00d 02' 27.3"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       135 [cnts]
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47488.28 SOD {13:11:28.28} UT,   76.0 [sec] since BAT Trigger Time
CENTROID_X:      276.26,  raw= 276  [pixels]
CENTROID_Y:      290.23,  raw= 290  [pixels]
ROLL:            64.66 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -18.31
GRB_POS_XRT_Z:   -61.36
IMAGE_URL:       sw00319584000msxps_rw.img
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 08"}
SUN_DIST:        140.94 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.28d {+16h 17m 08s}  -26.46d {-26d 27' 36"}
MOON_DIST:       110.31 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.95,-58.50 [deg] galactic lon,lat of the burst
ECL_COORDS:      357.18,  1.57 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:12:11 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     319584,   Seg_Num: 0
GRB_RA:          356.7936d {+23h 47m 10.4s} (J2000),
                 356.9039d {+23h 47m 36.9s} (current),
                 356.1531d {+23h 44m 36.7s} (1950)
GRB_DEC:          +0.3188d {+00d 19' 07.6"} (J2000),
                  +0.3667d {+00d 21' 59.9"} (current),
                  +0.0409d {+00d 02' 27.3"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       4.26e-09 [erg/cm2/sec]
GRB_SIGNIF:      11.61 [sigma]
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47488.28 SOD {13:11:28.28} UT,   76.0 [sec] since BAT Trigger Time
TAM[0-3]:        327.62 237.20 261.39 243.58
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 08"}
SUN_DIST:        140.94 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.28d {+16h 17m 08s}  -26.46d {-26d 27' 36"}
MOON_DIST:       110.32 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.95,-58.50 [deg] galactic lon,lat of the burst
ECL_COORDS:      357.18,  1.57 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.84 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:12:40 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     319584,   Seg_Num: 0
GRB_RA:          356.7936d {+23h 47m 10.4s} (J2000),
                 356.9039d {+23h 47m 36.9s} (current),
                 356.1531d {+23h 44m 36.7s} (1950)
GRB_DEC:          +0.3188d {+00d 19' 07.6"} (J2000),
                  +0.3667d {+00d 21' 59.9"} (current),
                  +0.0409d {+00d 02' 27.3"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       135 [cnts]
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47488.28 SOD {13:11:28.28} UT,   76.0 [sec] since BAT Trigger Time
CENTROID_X:      276.26,  raw= 276  [pixels]
CENTROID_Y:      290.23,  raw= 290  [pixels]
ROLL:            64.66 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -18.31
GRB_POS_XRT_Z:   -61.36
IMAGE_URL:       sw00319584000msxps_rw.img
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 08"}
SUN_DIST:        140.94 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.29d {+16h 17m 09s}  -26.46d {-26d 27' 38"}
MOON_DIST:       110.31 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.95,-58.50 [deg] galactic lon,lat of the burst
ECL_COORDS:      357.18,  1.57 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:13:55 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.316d {+00d 18' 56"} (J2000)
POINT_ROLL:      64.659d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47497.40 SOD {13:11:37.40} UT,   85.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.772
N_STARS:         26
X_OFFSET:        504 [pixels]
Y_OFFSET:        537 [pixels]
X_MAX:           1463 [pixels]
Y_MAX:           1496 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00319584000msufc0085.fits
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 07"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.30d {+16h 17m 11s}  -26.46d {-26d 27' 43"}
MOON_DIST:       110.28 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.91,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:14:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.316d {+00d 18' 56"} (J2000)
POINT_ROLL:      64.659d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47497.40 SOD {13:11:37.40} UT,   85.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.772
N_STARS:         26
X_OFFSET:        504 [pixels]
Y_OFFSET:        537 [pixels]
X_MAX:           1463 [pixels]
Y_MAX:           1496 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00319584000msufc0085.fits
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 07"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.30d {+16h 17m 13s}  -26.46d {-26d 27' 46"}
MOON_DIST:       110.28 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.91,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [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:     Sun 10 Aug 08 13:16:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.316d {+00d 18' 56"} (J2000)
ROLL:            64.659d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47497.40 SOD {13:11:37.40} UT,   85.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     240066700
X_OFFSET:        922 [pixels]
Y_OFFSET:        857 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       1017
BINNING_INDEX:   1
IM_URL:          sw00319584000msuni0085.fits
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 05"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.32d {+16h 17m 16s}  -26.46d {-26d 27' 52"}
MOON_DIST:       110.27 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.91,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [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:     Sun 10 Aug 08 13:16:16 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     319584,   Seg_Num: 0
GRB_RA:          356.779d {+23h 47m 07s} (J2000),
                 356.890d {+23h 47m 34s} (current),
                 356.139d {+23h 44m 33s} (1950)
GRB_DEC:          +0.320d {+00d 19' 11"} (J2000),
                  +0.368d {+00d 22' 03"} (current),
                  +0.042d {+00d 02' 31"} (1950)
GRB_DATE:        14688 TJD;   223 DOY;   08/08/10
GRB_TIME:        47412.28 SOD {13:10:12.28} UT
TRIGGER_INDEX:   146
GRB_PHI:          63.98 [deg]
GRB_THETA:        20.44 [deg]
DELTA_TIME:      71.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     14.73 [sigma]
IMAGE_SIGNIF:    7.59 [sigma]
LC_URL:          sw00319584000msb.lc
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 05"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.32d {+16h 17m 17s}  -26.47d {-26d 27' 53"}
MOON_DIST:       110.27 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.92,-58.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      357.17,  1.57 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 246.16,-15.75 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:16:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.316d {+00d 18' 56"} (J2000)
ROLL:            64.659d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47497.40 SOD {13:11:37.40} UT,   85.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     240066700
X_OFFSET:        922 [pixels]
Y_OFFSET:        857 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       1017
BINNING_INDEX:   1
IM_URL:          sw00319584000msuni0085.fits
SUN_POSTN:       140.71d {+09h 22m 50s}  +15.35d {+15d 21' 05"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.32d {+16h 17m 17s}  -26.47d {-26d 27' 54"}
MOON_DIST:       110.26 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.91,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:21:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.317d {+00d 19' 02"} (J2000)
POINT_ROLL:      64.657d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47603.41 SOD {13:13:23.41} UT,   191.1 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.432
N_STARS:         15
X_OFFSET:        602 [pixels]
Y_OFFSET:        537 [pixels]
X_MAX:           1561 [pixels]
Y_MAX:           1496 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00319584000msufc0191.fits
SUN_POSTN:       140.71d {+09h 22m 51s}  +15.35d {+15d 21' 02"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.36d {+16h 17m 27s}  -26.47d {-26d 28' 13"}
MOON_DIST:       110.23 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.92,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 10 Aug 08 13:21:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.317d {+00d 19' 02"} (J2000)
POINT_ROLL:      64.657d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47603.41 SOD {13:13:23.41} UT,   191.1 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.432
N_STARS:         15
X_OFFSET:        602 [pixels]
Y_OFFSET:        537 [pixels]
X_MAX:           1561 [pixels]
Y_MAX:           1496 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00319584000msufc0191.fits
SUN_POSTN:       140.71d {+09h 22m 51s}  +15.35d {+15d 21' 01"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.37d {+16h 17m 28s}  -26.47d {-26d 28' 16"}
MOON_DIST:       110.22 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.92,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [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:     Sun 10 Aug 08 13:22:12 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.317d {+00d 19' 02"} (J2000)
ROLL:            64.657d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47603.41 SOD {13:13:23.41} UT,   191.1 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     240066806
X_OFFSET:        922 [pixels]
Y_OFFSET:        857 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       1017
BINNING_INDEX:   1
IM_URL:          sw00319584000msuni0191.fits
SUN_POSTN:       140.71d {+09h 22m 51s}  +15.35d {+15d 21' 01"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.37d {+16h 17m 29s}  -26.47d {-26d 28' 18"}
MOON_DIST:       110.22 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.92,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [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:     Sun 10 Aug 08 13:22:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     319584,   Seg_Num: 0
POINT_RA:        356.776d {+23h 47m 06s} (J2000)
POINT_DEC:        +0.317d {+00d 19' 02"} (J2000)
ROLL:            64.657d
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47603.41 SOD {13:13:23.41} UT,   191.1 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     240066806
X_OFFSET:        922 [pixels]
Y_OFFSET:        857 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       1017
BINNING_INDEX:   1
IM_URL:          sw00319584000msuni0191.fits
SUN_POSTN:       140.71d {+09h 22m 51s}  +15.35d {+15d 21' 01"}
SUN_DIST:        140.96 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.38d {+16h 17m 30s}  -26.47d {-26d 28' 20"}
MOON_DIST:       110.21 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.92,-58.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      357.17,  1.57 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #8080
K. L. Page (U Leicester), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), P. A. Evans (U Leicester), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (MSSL), J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:
At 13:10:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080810 (trigger=319584). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 356.779, +0.320 which is
```
   RA(J2000) = 23h 47m 07s
   Dec(J2000) = +00d 19' 11"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multiple-peaked structure with a duration of about 140 sec, including a peak during the time of the XRT/UVOT observations. The peak count rate was ~3000 counts/sec (15-350 keV), at ~22 sec after the trigger.
The XRT began observing the field at 13:11:28.3 UT, 76.0 seconds after the BAT trigger. XRT found a bright, flaring, uncatalogued X-ray source located at RA, Dec 356.7936, +0.3188 which is equivalent to:
```
  RA(J2000)  = 23h 47m 10.4s
  Dec(J2000) = +00d 19' 07.6"
```
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 52 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
UVOT took a finding chart exposure of nominal 100 seconds with the White (160-650 nm) filter starting 88 seconds after the BAT trigger. There is a bright candidate afterglow in the list of sources generated on-board at
```
  RA(J2000)  =  23:47:10.5 = 356.79375
  DEC(J2000) = +00:19:10   =  +0.31944
```
with a 1-sigma error radius of about 1.0 arc sec. The estimated white magnitude is 14.7 with a 1-sigma error of about 0.5 mag. No correction has been made for a Galactic extinction corresponding to a reddening of 0.03 mag along the line of sight.
We note the presence of the galaxy J234710.47+001906.0 about 1.7 arcsec from the XRT position.
Burst Advocate for this burst is K. L. Page (kpa AT star.le.ac.uk). 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:     Sun 10 Aug 08 13:32:52 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     319584,   Seg_Num: 0
GRB_RA:          356.7937d {+23h 47m 10.48s} (J2000),
                 356.9040d {+23h 47m 36.95s} (current),
                 356.1532d {+23h 44m 36.77s} (1950)
GRB_DEC:          +0.3194d {+00d 19' 09.8"} (J2000),
                  +0.3673d {+00d 22' 02.1"} (current),
                  +0.0415d {+00d 02' 29.4"} (1950)
GRB_ERROR:       0.7 [arcsec radius, statistical only]
GRB_MAG:         14.69 +/- 0.50 [mag]
FILTER:          10, White
IMG_START_DATE:  14688 TJD;   223 DOY;   08/08/10
IMG_START_TIME:  47500.00 SOD {13:11:40.00} UT,   87.7 [sec] since BAT Trigger Time
SUN_POSTN:       140.72d {+09h 22m 53s}  +15.35d {+15d 20' 53"}
SUN_DIST:        140.95 [deg]   Sun_angle= 9.6 [hr] (West of Sun)
MOON_POSTN:      244.47d {+16h 17m 53s}  -26.48d {-26d 29' 04"}
MOON_DIST:       110.15 [deg]
MOON_ILLUM:      66 [%]
GAL_COORDS:       90.95,-58.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      357.18,  1.57 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The UVOT position is 1.8 arcsec from the XRT position.

GCN Circular #8081
Y. Ikejiri, M. Uemura, T. Ohsugi, K. Kawabata, A. Arai, M. Yamanaka, and K. Sakimoto (Hiroshima Univ.), report on behalf of the KANATA GRB team:
We performed optical-NIR observations of the field of GRB 080810 (GCN Circ. 8080) with TRISPEC attached to the "KANATA" 1.5-m telescope.
We confirmed a very bright, fading object at the position of the optical afterglow detected with UVOT. Our preliminary results are below:
```
time(UT)       mag.              exposure_time
Aug. 2008                        (sec)
10.553258      13.7  $B!^(B 0.1  V  33sec * 1
```
Comparison star: 23:46:58.51 +00:18:30.2 V=14.07 (NOMAD)
Further observation and analysis are ongoing.
GCN Circular #8082
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), K. L. Page (U Leicester), D. Palmer (LANL), G. Sato (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+381 sec from the recent telemetry downlink, we report further analysis of BAT GRB 080810 (trigger #319584) (Page, et al., GCN Circ. 8080). The BAT ground-calculated position is RA, Dec = 356.783, 0.310 deg which is
```
   RA(J2000)  =  23h 47m 08.0s 
   Dec(J2000) = +00d 18' 35.1" 
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 68%.
The mask-weighted light curve shows a cluster of overlapping peaks starting at ~T-20, the tallest at T+25 sec, and ending at ~T+120 sec. T90 (15-350 keV) is 106 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T-21.2 to T+111.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.34 +- 0.06. The fluence in the 15-150 keV band is 4.6 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+24.68 sec in the 15-150 keV band is 2.0 +- 0.2 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/319584/BA/
GCN Circular #8083
J.X. Prochaska (UCSC), D. Perley (UCB), A. Howard (UCB), H.-W. Chen (Chicago), G. Marcy (UCB), D. Fischer (SFSU), and C. Wilburn (Keck) report on behalf of GRAASP:
"We observed the afterglow of GRB 080810 with the Keck/HIRES echelle spectrometer for a series of 1000s exposures starting at UT 13:47:50 under good conditions. A quick analysis of the 2D images reveals a Lyman limit system at ~3975Ang. We tentatively associate this feature with the host galaxy of GRB 080810 and estimate a redshift z_GRB = 3.35.
Further analysis is in progress."
This GCN may be cited.
GCN Circular #8084
E.S. Rykoff (UCSB), reports on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB 080810 (Swift trigger 319584, GCN 8080, Page et al.). The first image was at 13:10:47.6 UT, 35.3 s after the burst (21.6 s after the GCN notice time), contemporaneous with the gamma-ray emission (GCN 8082, Sakamoto et al.). We took 10 5s exposures, 10 20s exposures, and 137 60s exposures under variable conditions. The unfiltered images are calibrated relative to USNO B1.0. We detect a 12.8 magnitude, variable source with coordinates:
23:47:10.5 +00:19:11.5 (J2000) (uncertainty of 1" or better)
```
start UT        mag     mlim(of image)
----------------------------------

13:11:16.7     12.8     16.5
```
The position is consistent with the XRT and UVOT positions reported in GCN 8080.
Our prompt detection shows the afterglow initially rising from 13.7 mag (38s post-burst) to a peak of 12.8 mag (67s post-burst). This is followed by a shallow decay from ~67s to ~230s (decay index alpha=-0.15+/-0.05), and a break to a steeper decay from ~230s to ~6000s post-burst (decay index alpha=-1.13+/-0.02). Preliminary analysis does not show any significant deviations from this smooth evolution.
A jpeg image is available at http://www.rotse.net/images/gsb319584_3a02_img.jpg The object in question is marked with yellow and blue circles.
GCN Circular #8085
M. Uemura, M. Yamanaka, Y. Ikejiri, K. Sakimoto, T. Ohsugi, K.S. Kawabata, and A. Arai, report on behalf of the KANATA GRB team:
We continue the observation of GRB 080810 with the KANATA 1.5-m telescope. We obtained V, J, and Ks-band images of the field of the afterglow using TRISPEC. The latest observation shows:
```
time(UT)    mag.   err   exposure time
Aug. 2008  
10.78444   18.92V  0.05   123sec * 10
10.78479   17.53J  0.31    72sec * 10
```
The light curve we obtained can be described with a simple power-law decay between 420 and 20000 sec after the GRB trigger, without an apparent break. The power-law index is calculated to be 1.21+/-0.02. The index is slightly, but significantly larger than that reported in GCN 8084, implying a possible break around the very early or very late phase of our observation period.
Further monitoring is encouraged.
GCN Circular #8086
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1614 s of XRT Photon Counting mode data and 3 UVOT images for GRB 080810, 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 = 356.79418, +0.32000 which is equivalent to:
```
RA (J2000): 23h 47m 10.60s
Dec (J2000): +00d 19' 12.0"
```
with an uncertainty of 1.4 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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method.
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #8087
K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:
We have analysed the first four orbits of the XRT data obtained for GRB 080810 (Page et al., GCN Circ. 8080). The first orbit (376 s) was taken entirely in Windowed Timing (WT) mode, followed by 2.8 of Photon Counting (PC) data. The UVOT-enhanced position was given by Evans et al. in GCN Circ. 8086.
The WT data show a number of flares, with the strongest peaking around 107 and 209 s after the trigger; the first of these is also visible in the BAT data. The PC data in later orbits can be modelled with a single power-law decay, with alpha = 1.20 +0.12/-0.11.
There is strong spectral evolution throughout the first orbit, as is typical for flaring activity. A spectrum extracted from the PC mode data (3.8-12.1 ks after the trigger) can be fitted with a power-law of Gamma = 1.98 +/- 0.06, absorbed by the Galactic column in this direction of 3.28x10^20 cm^-2. The observed (unabsorbed) flux over this time is 1.99 (2.20) x 10^-11 erg cm^-2 s^-1.
If the decay continues with alpha = 1.2, the predicted count-rate at 24 hours is 0.02 count s^-1, corresponding to an observed (unabsorbed) flux of 8.5 (9.4) x 10^-13 erg cm^-2 s^-1.
This is an official product of the Swift-XRT team.
GCN Circular #8088
R. Burenin (IKI), I. Khamitov (TUG), A. Galeev, I. Bikmaev, N. Sakhibullin (KSU/AST), M. Pavlinsky, R. Sunyaev (IKI), Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)
We observed the GRB 080810 afterglow with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey). We made a set of exposures in BVRI between 8.3 and 12.6 hours after the burst. During our observations the OT faded from 19.1 to 19.5 in R (USNO-B1.0 calibrated).
We also obtained a set of low resolution spectra using TFOSC spectrometer. We detected Ly and other absorption lines and confirm the redshift z=3.35 measured by Prochaska et al. (GCN 8083). Further analysis is ongoing.
GCN Circular #8089
A. de Ugarte Postigo (ESO), C.C. Thoene, J.P.U. Fynbo, J. Hjorth (DARK/NBI), P. Jakobsson (U. Hertfordshire), Z. Banhidi (NOT, IAC), F. Grundahl, T. Arentoft (U. of Aarhus) report on behalf of a larger collaboration:
We have observed the afterglow of GRB 080810 (Page et al. GCN 8080) from the Nordic Optical Telescope (NOT, Roque de los Muchachos Observatory, La Palma, Spain) using ALFOSC. The observations started on 10.9899 Aug (10.59 hours after the burst), when we measure an R-band magnitude of 19.1+/-0.2 (based on USNO-1B photometry). This value is in agreement with the slope decay measured by Rykoff (GCN 8084) implying that no break has been produced between both observations. This is also consistent with the magnitudes reported by Burenin et al. (GCN 8088). We obtained the following coordinates for the afterglow (J2000+/-0.5"):
```
R.A.: 23:47:10.51
Dec.: +00:19:11.3
```
This value is slightly off from the value provided by UVOT (Page et al. GCN 8080) but fully consistent with the one given by Rykoff (GCN 8084).
We also obtained spectroscopic observations of the afterglow, where we clearly detect Ly-alpha absorption, a flux drop blueward of the Lyman break as well as other absorption lines, including the CIV/CIV doublet at a redshift of z~3.35, in agreement to what was reported by Prochaska et al. (GCN 8083) and Burenin et al. (GCN 8088).
GCN Circular #8090
A. de Ugarte Postigo (ESO), F. Aceituno, A.J. Castro-Tirado (IAA-CSIC) report on behalf of a larger collaboration:
We have observed the field of GRB 080810 (Page et al. GCN 8080) with the 1.5m OSN telescope at Sierra Nevada Observatory (Granada, Spain), covering the range between 11.93 and 15.11 hours after the burst in B, V, R and I bands. We observe a continuous decay following a slope of alpha = -1.11+/-0.02, consistent with the slope provided by Rykoff et al. (GCN 8084). Preliminary analysis shows the following magnitudes in an intermediate epoch as compared to reference stars derived from the SDSS.
```
t-t0(h)  Filter      Mag
 13.82     B     21.4 +/- 0.3
 13.62     V     20.2 +/- 0.2
 13.85     R     19.5 +/- 0.2
 13.25     I     19.2 +/- 0.2
```
GCN Circular #8091
Y.Okuma, H.Fujimoto, T.Nashimoto, A.Wada, D.Yonetoku, T. Murakami, report on behalf of the Kanazawa GRB team:
We have imaged the field of GRB 080810 (Page et al. GCN 8080) in R-band with 0.4m telescope at Kanazawa Japan. We obtained the first image at one and half hours after the Swift trigger. We confirmed the bright optical counter part reported by Page et al. (GCN 8080), Ikejiri et al. (GCN 8081), and so on. Compared with the USNO-A2.0 catalog, the source magnitude is determined about 16.5 +/- 0.2 mag with 30 seconds exposure time from the begining of this observation. Further analysis is in progress.
GCN Circular #8092
M. Kocka (kocka@sunkl.asu.cas.cz), M. Nekola, J. Strobl, R. Hudec, C. Polasek (AsU CAS - Ondrejov), M. Jelinek, P. Kubanek (IAA-CSIC - Granada), F. Munz (IASF/INAF - Bologna)
The 0.5m D50 telescope in the Ondrejov Observatory of the Astronomical Institute of the Academy of Sciences of the Czech Republic, observed GRB 080810.Observation started at 22:26:41 UT (~9.4 hours after SWIFT detection).
After 80x20 sec exposure we detected optical counterpart at the coordinates: 23:47:10.5 +00:19:11.5 (J2000)(E.S. Rykoff GCN 8084) Calibrated to near USNO-B1.0 catalog star with the following results:
```
    time(UT) mid of exp     mag.   err   exposure time
    22:39:02        19.6    0.5    80x20 sec
```
image: http://zeus.asu.cas.cz/~koci/grb080810/GRB080810.jpg
D50 telescope is controled by RTS2 software.
Further analysis is in progress
This message may be cited.
GCN Circular #8093
C. Guidorzi (INAF-OAB), I. Steele (LJMU), N. Tanvir (U. Leicester) on behalf of a larger collaboration report:
On 2008 August 11 (03:53:56 UT) we began observing the field of GRB 080810 (Page et al. GCN Circ. 8080) with the Liverpool Telescope using the r' and i' filters.
The optical afterglow is clearly detected at the position reported by ROTSE-III (Rykoff GCN Circ. 8084) and the NOT (de Ugarte Postigo et al. GCN Circ. 8089). We found the following magnitudes:
```
Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-------------------------------------------------------------
LT          i'        14.770       300         19.14 +/- 0.04
LT          r'        15.328       300         19.93 +/- 0.04
-------------------------------------------------------------
```
The calibration was performed using the R2 and I magnitudes of the following nearby USNOB1 catalogue star: 23:47:06.819, +00:19:27.15, using R2=15.31, I=14.69.
GCN Circular #8094
M. Andreev, (Terskol Branch of Institute of Astronomy), Ju. Babina (CrAO), V. Petkov, A. Kurenya (BNO INR RAS), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed the afterglow of GRB080810 (Page et al. GCN 8080) with Zeiss-600 of Mt.Terskol observatory in R-band on Aug. 11. The afterglow is detected in a combined image in a position consistent with coordinates reported by Rykoff (GCN 8084). A photometry of the OT against USNO-B1.0 stars is following:
```
T0+       Exposure  R_mag
(mid)

0.45598 d  8x180 s   19.4 +/- 0.2 
```
GCN Circular #8095
S. T. Holland (CRESST/USRA/GSFC) & K. L. Page (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 080810 starting 65 s after the BAT trigger (Page et al., GCNC. 8080). Settled observations started at T + 85 s. We detect the optical afterglow (Page et al., GCNC 8080) in the v, b, and white filters at the UVOT-enhanced location of the XRT afterglow (Evans et al., 2008, GCNC 8086). The refined UVOT source position is
```
  RA (J2000.0) =  23:47:10.26
 Dec (J2000.0) = +00:19:11.3
```
with an estimated uncertainty of +/-0.6 arcsec (radius, 90% confidence). This is consistent with the positions of the optical afterglow reported by Rykoff (GCNC 8084) and de Ugarte Postigo (GCNC 8089)
Magnitudes and upper limits are reported below.
```
Filter     T_start (s) T_stop  Exposure      Mag  Err  Comment
white           85        185        98     14.63 0.07
   v            191        459       264     14.06 0.06
   b           4432       4632       197     17.85 0.08
   u           4227     68,686       727    >21.4       3-sigma UL
  uvw1         4022     68,283      3099    >22.3       3-sigma UL
  uvm2         3817     62,540      3229    >22.2       3-sigma UL
  uvw2         4843     50,866      1510    >22.0       3-sigma UL
```
The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.03 mag (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383,627). The non-detections in the u, uvw1, uvm2, and uvw2 filters are consistent with a redshift of z = 3.35 (Prochaska, GCNC 8083). The power-law decay index in the b band between 4532 and 27,387 s is -1.29 +/- 0.22.
GCN Circular #8097
M. Yoshida, K. Yanagisawa, D. Kuroda, Y. Shimizu, S. Nagayama, H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the optical afterglow (Ikejiri et al. GCN 8081; Rykoff GCN 8084) of GRB 080810 (Page et al. GCN 8080) with the optical three color (g', Rc and Ic) imager attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. Photometric results are listed below. We used USNO-B1.0 stars for flux calibration.
```
Mid-UT      exp-T          g'            Rc            Ic
--------------------------------------------------------------
2008-08
10.60244   300 sec   17.16+/-0.06  16.70+/-0.04  15.69+/-0.05
--------------------------------------------------------------
```
GCN Circular #8098
A. Galeev (KSU/AST), I. Khamitov (TUG), I. Bikmaev, N. Sakhibullin (KSU/AST), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)
report:
We observed the GRB 080810 afterglow with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey).
The serie of 600 sec (Ic), 600 sec (Rc), 900 sec (V) exposures was made by using TFOSC instrument under moderate seeing, starting at 12 Aug 2008, 01:19 UT, i.e. 36.16 hours after the burst.
The OT is clearly detected on all images. Using USNO-B1.0 stars we estimate an Rc magnitude of 20.66+/-0.03 (~36.4 hours after the burst). Using our earlier observations (Burenin et al., GCN8088) the calculated power law index is -0.91+/-0.09 for decay from ~8.3 h to ~36.4 h.
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GCN Circular #8099
C. Guidorzi (INAF-OAB), D. Bersier (LJMU) and N. Tanvir (U. Leicester) report on behalf of a larger collaboration:
We observed GRB 080810 (Page et al. GCN Circ. 8080) with the 2 m Liverpoo= l and Faulkes North telescopes starting on August 11 (23:34:09 UT) and 12 (13:14:49 UT), respectively, with r' and i' filters. We clearly detect the afterglow with the following magnitudes:
```
Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-------------------------------------------------------------
LT          i'        34.657       6x300       20.01 =B1 0.06
LT          r'        39.525       6x300       20.78 =B1 0.05
FTN         i'        48.367       5x300       20.38 =B1 0.04
-------------------------------------------------------------
```
The calibration was performed using nearby USNOB1 stars as described in our previous report (Guidorzi et al. GCN Circ. 8093). Combining with our previous observation, we derive a power-law index of 0.94 =B1 0.05 from 15 to 48 hr post burst, thus confirming the flattening of the optical decay, in agreement with Galeev et al. (GCN Circ. 8098).
GCN Circular #8100
C.A. Meegan (NASA/MSFC), J. Greiner (MPE), N.P. Bhat (UAH), E. Bissaldi (MPE), M.S. Briggs (UAH), V. Connaughton (UAH), R. Diehl (MPE), G.J. Fishman (NASA/MSFC), L. Gibby (NASA/MSFC), A.S. Hoover (LANL), A.J. van der Horst (NASA/ORAU), A. von Kienlin (MPE), R.M. Kippen (LANL), C. Kouveliotou (NASA/MSFC), G.G. Lichti (MPE), S. McBreen (MPE), W.S. Paciesas (UAH), R.D. Preece (UAH), H. Steinle (MPE), M.S. Wallace (LANL), and C.A. Wilson-Hodge (NASA/MSFC)report:
"At 13:10:12 UT on 10 August 2008, the GLAST Burst Monitor (GBM) triggered and located GRB 080810 (GBM 080810.549, trigger 240066613), which was also detected by Swift (Page et al., GCN 8080). The on-ground calculated location, using the GBM trigger data, is RA, Dec 357.18, -4.61 which is equivalent to
```
    RA(J2000) = 23h 49m
    Dec(J2000) = -4d 37'
```
with an uncertainty of 5.0 degrees (radius, 1-sigma containment, statistical only). The angle from the Large Area Telescope (LAT) boresight is 61 degrees.
The GBM light curve shows a slow rise starting at T0-20, followed by a main emission phase comprising 5 pulses, a quiescent period and a sixth pulse at T0+102 s.
The time-averaged spectrum from T-0.5 to T+53.1 sec is best fit by a power law function with an exponential high energy cutoff. The cutoff energy is 313.5 +/-73.6 keV and the power law index is -0.91 +/-0.12, with a reduced chi-square of 1.1 for 226 degrees of freedom.
The fluence in the 50-300 keV band is (6.9 +/- 0.5) x 10^-6 erg/cm2. The 1-sec photon flux measured from T+23.5 sec in the 50-300 keV band is 1.85 +/- 0.16 ph/cm2/sec. All the quoted errors are at the 90% confidence level."
GCN Circular #8101
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), and T. Ukwatta (GWU) on behalf of the Swift-BAT team:
V. Pal'shin, S. Golenetskii, R.Aptekar, E. Mazets, D. Frederiks, and T. Cline on behalf of the Konus-Wind team,
Report:
We performed the Konus-Wind and the Swift/BAT joint spectral analysis of GRB 080810 (Swift/BAT trigger #319584; Page et al., GCN Circ. 8080). Since the Konus-Wind observed this GRB in the waiting mode, we only have 3 channel spectral data for the Konus-Wind. However, the Konus-Wind data covers the energy range from 20 keV to 1 MeV. Therefore, the joint spectral analysis of the Konus-Wind and the Swift/BAT data enables to derive the broad-band spectral parameters of this burst.
The time interval of the spectral data for each instrument is chosen from T0(BAT)-18.6 to T0(BAT)+60.8 sec where T0(BAT) is the trigger time of BAT at 13:10:12.3 UTC. This time interval includes most of the burst emission, but not the last pulse around T0(BAT)+~100 sec which is clearly visible in the BAT data (Sakamoto et al., GCN Circ. 8082). The energy ranges which we used in the joint spectral analysis are 20-1000 keV and 14-150 keV for the Konus-Wind and the Swift/BAT respectively. The spectral data of two instruments are fit with the spectral model multiplied by the constant factor to take into account the systematic uncertainties in the response matrices of each instrument.
The spectrum is well fit with a power-law with exponential cutoff model (dN/dE ~ E^{alpha} * exp(-(2+alpha)*E/Epeak)). The constant factors of each instrument agree within 20%. No systematic residual from the best fit model is seen in the spectral data of each instrument. The best fit spectral parameters are: alpha = -1.2 +- 0.1 and Epeak = 550 (-230/+860) keV (chi2/dof = 41/58). The best fit spectral parameters for the Band function fixing beta=-2.5 are: alpha = -1.2 +- 0.1 and Epeak = 580 (-260/+850) keV (chi2/dof = 41/58). The energy fluence in the 15-1000 keV band calculated by a power-law with exponential cutoff model for this 79.5 sec interval is 1.7 (-0.2/+0.1) x 10^-5 erg/cm2 (assuming the constant factor of the BAT is fixed to 1).
Assuming z = 3.35 (Prochaska et al., GCN Circ. 8083; Burenin et al., GCN Circ. 8088) and a standard cosmology model with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73, the isotropic energy release is E_iso ~5 x 10^53 erg in 1 keV to 10 MeV at the GRB rest frame extrapolating the best fit model spectrum.
All the quoted errors are at the 90% confidence level.
GCN Circular #8102
A. Galeev (KSU/AST), I. Khamitov (TUG), I. Bikmaev, N. Sakhibullin (KSU/AST), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)
report:
We observed the GRB 080810 afterglow (Page et al. GCN Circ. 8080) with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey).
The series of several exposures in V,Rc,Ic bands were made by using Andor CCD starting at 13 Aug 2008, 00:24 UT, i.e. ~ 59.23 hours after the burst.
Using USNO-B1.0 stars we estimate an Rc magnitude of 21.60+/-0.05 (~59.85 hours after the burst).
This measurement deviates from the power law decay with index -0.9 (Galeev et al., GCN8098,Guidorzi et al, GCN8099), that indicates steeper fading of OT after 48h.
GCN Circular #8103
P. Chandra (UVA/NRAO) and D. A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We observed the field centered at the UVOT position of the Swift burst GRB 080810 (GCN 8080) using the Very Large Array (VLA) at a frequency of 8.46 GHz and starting at 2008 Aug 13.36 UT. We detect the radio flux at the GRB afterglow position with the flux density of 151 =B1 50 uJy.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Circular #8105
V. Rumyantsev, Yu. Efimov (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the optical afterglow of GRB080810 (Page et al., GCN 8080) in R-band on Aug.10 between (UT) 23:17:05 - 23:48:32 with AZT-8 telescope of CrAO. The afterglow is detect in a separate images in coordinates RA(J2000) = 23 47 10.4, Dec(J2000) = +00 19 11.0 with uncertainty 0.5". The coordinates are consistent with reported early (Page et al. GCN 8080, Rykoff GCN 8084, A. de Ugarte Postigo et al. GCN 8090). Based on USNO-B1.0 star RA (J2000) = 23 47 11.12, Dec. (J2000) = +00 16 38.30, R=16.30 we estimated brightness of the optical afterglow:
```
T0+,         Exposure,     R_mag,   err
(mid time)

0.4331 d  15x120 s     19.20  +/- 0.05
```
GCN Circular #8106
Christina C. Thoene (DARK/NBI), Antonio de Ugarte Postigo (ESO) and Christine Liebig (ARI Heidelberg) report:
We observed the field of GRB 080810 (Page et al. GCN 8080) with the Danish 1.54m telescope on La Silla/Chile on August 15.40 UT and 16.31 UT (4.85 and 5.76 days after the burst onset). We detect the decaying afterglow at preliminary R-band magnitudes of 22.8+/-0.3 and 23.2+/-0.5.
Using the R band and unfiltered magnitudes published in GCNs (Rykoff et al. GCN 8084, Burenin et al. GCN 8088, de Ugarte Postigo et al. GCN 8089 & 8090, Okuma et al. GCN 8091, Kocka et al. GCN 8092, Guidorzi et al. GCN 8093 & 8099, Andreev et al. GCN 8094, Yoshida et al. GCN 8097, Galeev et al. GCN 8098 & 8102, Rumyantsev et al. GCN 8105) together with the data of our own observations we find that the light curve can be described by a powerlaw of index alpha = 1.12 +/- 0.02 between 400s and 1 day after the burst. After 1 day there is a flux excess that can be seen both in the optical and X-ray light curves (explaining the flattening measured by Galeev et al., GCN8098 and Guidorzi et al., GCN8099), after which the light curve begins to decay more steeply with an index in the optical of alpha = 1.8 +/- 0.3.
Hail, thunderstorm and heavy rain currently prevent further observations from the DK 1.54m.
C. Thoene and C. Liebig acknowledge the excellent cheese fondue at the Swiss telescope yesterday evening.
GCN Report 157.1
GCN_Report 157.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_157_1.pdf by K.L. Page at U. Leicester titled: "Final results on Swift GRB 080810"
GCN Report 157.2
GCN_Report 157.2 has been posted: http://gcn.gsfc.nasa.gov/reports/report_157_2.pdf by K.L. Page at U. Leicester titled: "Revised final observations of Swift GRB 080810"
GCN Circular #8722
A. Volnova (SAI MSU), I. Korobtsev (ISTP), A. Pozanenko (IKI), E. Klunko (ISTP), N. Bochkarev (SAI MSU), E. Karitskaja (Institute of Astronomy), on behalf of larger GRB follow up collaboration report:
We observed the afterglow of GRB 080810 (Page et al. GCN 8080) with 1.5 m telescope of Sayan observatory (Mondy) under good weather conditions. Series of R and B images were obtained between Aug. 10 (UT) 16:50:03 -18:17:06. While we clearly detect afterglow in single R images, the afterglow is not detected in a combined image obtained in B. A photometry of the combined images is based on several SDSS nearby stars:
```
  T0+         Filter  Exp.    mag.           Upper_Limit seeing
 mid., days                                 (3 sigma)

  0.1599      B      14x60    n/d            19.26      ~2.7"
  0.1786      R      30x60   17.98 +/- 0.13  20.85      ~2.2"
  0.2026      R      30x60   18.10 +/- 0.17  21.14      ~2.0"
```
The photometry in R-band is an agreement with power law decay index of light curve (alpha = 1.12) between 400 s and 1 day after the burst reported by Thoene et al (GCN 8106).
GCN Circular #8728
A. Volnova (SAI MSU), R. Karimov (MAO), A. Pozanenko (IKI), M. Ibrahimov (MAO) on behalf of larger GRB follow up collaboration report:
We observed the afterglow of GRB 080810 (Page et al. GCN 8080) with AZT-22 (1.5 m) telescope of Maidanak observatory (MAO) in R band on Aug. 12 (UT) (20:18:17 - 21:07:58) and Aug. 14 (20:26:35 - 21:33:00). A photometry of combined images is based on several SDSS DR6 field stars:
```
T0+         Filter  Exp.  mag.           UL
mid., days                               (3 sigma)

2.315      R      2700    21.36 +/-0.09  23.10
4.326      R      3600    n/d            22.30
```
The photometry in R-band is an agreement with power law decay index (alpha = 1.8) reported by Thoene et al (GCN 8106) for this phase of the light curve.

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Jochen Greiner, last update: 25-Dec-2008 [Disclaimer]