Gamma-ray Burst 091208B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:50:13 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     281958599
GRB_RA:           28.567d {+01h 54m 16s} (J2000),
                  28.706d {+01h 54m 49s} (current),
                  27.865d {+01h 51m 28s} (1950)
GRB_DEC:         +24.917d {+24d 54' 60"} (J2000),
                 +24.965d {+24d 57' 55"} (current),
                 +24.671d {+24d 40' 17"} (1950)
GRB_ERROR:       8.68 [deg radius, statistical plus systematic]
GRB_INTEN:       292 [cnts/sec]
DATA_SIGNIF:     12.20 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        15173 TJD;   342 DOY;   09/12/08
GRB_TIME:        35397.96 SOD {09:49:57.96} UT
GRB_PHI:         118.00 [deg]
GRB_THETA:        50.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      1.69
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      85%  GRB
2nd_MOST_LIKELY:  14%  Generic SGR
DETECTORS:       1,0,0, 0,0,0, 0,0,0, 1,1,0, 0,0,
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 47"}
SUN_DIST:        137.56 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.75d {+10h 35m 01s}   +4.90d {+04d 54' 07"}
MOON_DIST:       123.03 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      140.55,-35.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       35.37, 12.36 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 189.65,8.12 [deg].

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:50:22 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     378559,   Seg_Num: 0
GRB_RA:           29.410d {+01h 57m 39s} (J2000),
                  29.546d {+01h 58m 11s} (current),
                  28.729d {+01h 54m 55s} (1950)
GRB_DEC:         +16.883d {+16d 52' 57"} (J2000),
                 +16.931d {+16d 55' 51"} (current),
                 +16.639d {+16d 38' 21"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4692 [cnts]    Image_Peak=168 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   147     E_range: 25-100 keV
BKG_INTEN:       25761 [cnts]
BKG_TIME:        35386.67 SOD {09:49:46.67} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15173 TJD;   342 DOY;   09/12/08
GRB_TIME:        35397.99 SOD {09:49:57.99} UT
GRB_PHI:         146.67 [deg]
GRB_THETA:        47.29 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     24.57 [sigma]
IMAGE_SIGNIF:    9.31 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +0 +72  +0 
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 47"}
SUN_DIST:        136.76 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      158.76d {+10h 35m 01s}   +4.90d {+04d 54' 04"}
MOON_DIST:       125.29 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.87,-43.15 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       33.26,  4.56 [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 = 217.12,-0.64 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:50:26 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      59
TRIGGER_NUM:     281958599
GRB_RA:           28.533d {+01h 54m 08s} (J2000),
                  28.673d {+01h 54m 42s} (current),
                  27.831d {+01h 51m 19s} (1950)
GRB_DEC:         +25.233d {+25d 13' 60"} (J2000),
                 +25.282d {+25d 16' 55"} (current),
                 +24.988d {+24d 59' 16"} (1950)
GRB_ERROR:       4.73 [deg radius, statistical plus systematic]
GRB_INTEN:       1350 [cnts/sec]
DATA_SIGNIF:     41.30 [sigma]
INTEG_TIME:      0.512 [sec]
GRB_DATE:        15173 TJD;   342 DOY;   09/12/08
GRB_TIME:        35397.96 SOD {09:49:57.96} UT
GRB_PHI:         118.00 [deg]
GRB_THETA:        50.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO:      1.10
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       1,0,0, 0,0,0, 0,0,0, 1,1,0, 0,0,
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 47"}
SUN_DIST:        137.57 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.76d {+10h 35m 02s}   +4.90d {+04d 54' 03"}
MOON_DIST:       122.93 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      140.40,-35.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       35.46, 12.67 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 189.65,8.12 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:50:37 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     281958599
GRB_RA:           32.880d {+02h 11m 31s} (J2000),
                  33.018d {+02h 12m 04s} (current),
                  32.189d {+02h 08m 45s} (1950)
GRB_DEC:         +18.870d {+18d 52' 12"} (J2000),
                 +18.916d {+18d 54' 59"} (current),
                 +18.635d {+18d 38' 07"} (1950)
GRB_ERROR:       3.11 [deg radius, statistical only]
DATA_SIGNIF:     14.40 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        15173 TJD;   342 DOY;   09/12/08
GRB_TIME:        35397.96 SOD {09:49:57.96} UT
GRB_PHI:         127.00 [deg]
GRB_THETA:        52.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 47"}
SUN_DIST:        140.45 [deg]   Sun_angle= -9.2 [hr] (East of Sun)
MOON_POSTN:      158.76d {+10h 35m 02s}   +4.90d {+04d 54' 01"}
MOON_DIST:       121.52 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      147.98,-40.07 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       37.05,  5.30 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:50:39 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      62
TRIGGER_NUM:     281958599
GRB_RA:           30.150d {+02h 00m 36s} (J2000),
                  30.286d {+02h 01m 09s} (current),
                  29.467d {+01h 57m 52s} (1950)
GRB_DEC:         +17.300d {+17d 18' 00"} (J2000),
                 +17.348d {+17d 20' 52"} (current),
                 +17.058d {+17d 03' 30"} (1950)
GRB_ERROR:       2.64 [deg radius, statistical only]
DATA_SIGNIF:     40.40 [sigma]
DATA_INTERVAL:   0.512 [sec]
GRB_DATE:        15173 TJD;   342 DOY;   09/12/08
GRB_TIME:        35397.96 SOD {09:49:57.96} UT
GRB_PHI:         126.00 [deg]
GRB_THETA:        55.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 47"}
SUN_DIST:        137.55 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      158.76d {+10h 35m 02s}   +4.90d {+04d 54' 00"}
MOON_DIST:       124.49 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      145.57,-42.51 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       34.07,  4.71 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Tue 08 Dec 09 09:50:52 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    5962,   Sub_Num: 0
GRB_INTEN:      9.38 [sigma]   
GRB_TIME:       35397.41 SOD {09:49:57.41} UT
GRB_DATE:       15173 TJD;   342 DOY;   09/12/08
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2009-12/2009-12-08T09-49-57.2114-00346-00007-0.lc

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:52:24 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.895d {+16d 53' 41"} (J2000)
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35513.14 SOD {09:51:53.14} UT,   115.2 [sec] since BAT Trigger Time
COUNTS:          11    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    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:     Tue 08 Dec 09 09:53:55 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     378559,   Seg_Num: 0
GRB_RA:           29.410d {+01h 57m 39s} (J2000),
                  29.546d {+01h 58m 11s} (current),
                  28.729d {+01h 54m 55s} (1950)
GRB_DEC:         +16.883d {+16d 52' 57"} (J2000),
                 +16.931d {+16d 55' 51"} (current),
                 +16.639d {+16d 38' 21"} (1950)
GRB_DATE:        15173 TJD;   342 DOY;   09/12/08
GRB_TIME:        35397.99 SOD {09:49:57.99} UT
TRIGGER_INDEX:   147
GRB_PHI:         146.67 [deg]
GRB_THETA:        47.29 [deg]
DELTA_TIME:      -11.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     24.57 [sigma]
IMAGE_SIGNIF:    9.31 [sigma]
LC_URL:          sw00378559000msb.lc
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.76 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      158.79d {+10h 35m 09s}   +4.89d {+04d 53' 10"}
MOON_DIST:       125.32 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.87,-43.15 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       33.26,  4.56 [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 = 217.12,-0.64 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:55:08 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.895d {+16d 53' 41"} (J2000)
POINT_ROLL:      254.507d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35517.49 SOD {09:51:57.49} UT,   119.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.721
N_STARS:         21
X_OFFSET:        222 [pixels]
Y_OFFSET:        508 [pixels]
X_MAX:           1181 [pixels]
Y_MAX:           1467 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00378559000msufc0119.fits
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.80d {+10h 35m 12s}   +4.88d {+04d 52' 52"}
MOON_DIST:       125.36 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:55:45 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.895d {+16d 53' 41"} (J2000)
POINT_ROLL:      254.507d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35517.49 SOD {09:51:57.49} UT,   119.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.721
N_STARS:         21
X_OFFSET:        222 [pixels]
Y_OFFSET:        508 [pixels]
X_MAX:           1181 [pixels]
Y_MAX:           1467 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00378559000msufc0119.fits
SUN_POSTN:       255.27d {+17h 01m 06s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.80d {+10h 35m 13s}   +4.88d {+04d 52' 42"}
MOON_DIST:       125.37 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.58 [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:     Tue 08 Dec 09 09:56:33 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.895d {+16d 53' 41"} (J2000)
ROLL:            254.507d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35517.49 SOD {09:51:57.49} UT,   119.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     281958722
X_OFFSET:        541 [pixels]
Y_OFFSET:        827 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       701
Y_GRB_POS:       987
BINNING_INDEX:   1
IM_URL:          sw00378559000msuni0125.fits
SUN_POSTN:       255.27d {+17h 01m 06s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.81d {+10h 35m 15s}   +4.88d {+04d 52' 30"}
MOON_DIST:       125.38 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.58 [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:     Tue 08 Dec 09 09:57:01 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.895d {+16d 53' 41"} (J2000)
ROLL:            254.507d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35517.49 SOD {09:51:57.49} UT,   119.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     281958722
X_OFFSET:        541 [pixels]
Y_OFFSET:        827 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       701
Y_GRB_POS:       987
BINNING_INDEX:   1
IM_URL:          sw00378559000msuni0125.fits
SUN_POSTN:       255.27d {+17h 01m 06s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.82d {+10h 35m 16s}   +4.87d {+04d 52' 23"}
MOON_DIST:       125.38 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:56:40 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     378559,   Seg_Num: 0
GRB_RA:           29.3922d {+01h 57m 34.12s} (J2000),
                  29.5278d {+01h 58m 06.66s} (current),
                  28.7109d {+01h 54m 50.62s} (1950)
GRB_DEC:         +16.8896d {+16d 53' 22.5"} (J2000),
                 +16.9378d {+16d 56' 15.9"} (current),
                 +16.6462d {+16d 38' 46.4"} (1950)
GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35533.00 SOD {09:52:13.00} UT,   135.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       255.27d {+17h 01m 06s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.74 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      158.81d {+10h 35m 15s}   +4.87d {+04d 52' 28"}
MOON_DIST:       125.36 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.85,-43.15 [deg] galactic lon,lat of the burst
ECL_COORDS:       33.24,  4.57 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
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.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 09:55:08 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.895d {+16d 53' 41"} (J2000)
POINT_ROLL:      254.507d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35517.49 SOD {09:51:57.49} UT,   119.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.721
N_STARS:         21
X_OFFSET:        222 [pixels]
Y_OFFSET:        508 [pixels]
X_MAX:           1181 [pixels]
Y_MAX:           1467 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00378559000msufc0119.fits
SUN_POSTN:       255.27d {+17h 01m 05s}  -22.75d {-22d 44' 48"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.80d {+10h 35m 12s}   +4.88d {+04d 52' 52"}
MOON_DIST:       125.36 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 10:04:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.897d {+16d 53' 49"} (J2000)
POINT_ROLL:      254.510d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35731.03 SOD {09:55:31.03} UT,   333.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.769
N_STARS:         30
X_OFFSET:        0 [pixels]
Y_OFFSET:        268 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1707 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00378559000msufc0333.fits
SUN_POSTN:       255.28d {+17h 01m 07s}  -22.75d {-22d 44' 50"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.88d {+10h 35m 31s}   +4.84d {+04d 50' 36"}
MOON_DIST:       125.45 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 10:04:30 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.897d {+16d 53' 49"} (J2000)
POINT_ROLL:      254.510d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35731.03 SOD {09:55:31.03} UT,   333.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.769
N_STARS:         30
X_OFFSET:        0 [pixels]
Y_OFFSET:        268 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1707 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00378559000msufc0333.fits
SUN_POSTN:       255.28d {+17h 01m 07s}  -22.75d {-22d 44' 50"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.88d {+10h 35m 32s}   +4.84d {+04d 50' 29"}
MOON_DIST:       125.45 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  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:     Tue 08 Dec 09 10:04:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.897d {+16d 53' 49"} (J2000)
POINT_ROLL:      254.510d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35731.03 SOD {09:55:31.03} UT,   333.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.769
N_STARS:         30
X_OFFSET:        0 [pixels]
Y_OFFSET:        268 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1707 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00378559000msufc0333.fits
SUN_POSTN:       255.28d {+17h 01m 07s}  -22.75d {-22d 44' 50"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.88d {+10h 35m 31s}   +4.84d {+04d 50' 36"}
MOON_DIST:       125.45 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  4.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 10:05:15 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     378559,   Seg_Num: 0
GRB_RA:           29.3919d {+01h 57m 34.05s} (J2000),
                  29.5275d {+01h 58m 06.59s} (current),
                  28.7106d {+01h 54m 50.55s} (1950)
GRB_DEC:         +16.8899d {+16d 53' 23.6"} (J2000),
                 +16.9381d {+16d 56' 17.0"} (current),
                 +16.6465d {+16d 38' 47.4"} (1950)
GRB_ERROR:       2.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35533.00 SOD {09:52:13.00} UT,   135.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       255.28d {+17h 01m 07s}  -22.75d {-22d 44' 51"}
SUN_DIST:        136.74 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.89d {+10h 35m 33s}   +4.84d {+04d 50' 18"}
MOON_DIST:       125.45 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.85,-43.15 [deg] galactic lon,lat of the burst
ECL_COORDS:       33.24,  4.57 [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

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 10:05:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.897d {+16d 53' 49"} (J2000)
ROLL:            254.510d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35731.03 SOD {09:55:31.03} UT,   333.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     281958936
X_OFFSET:        559 [pixels]
Y_OFFSET:        827 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       719
Y_GRB_POS:       987
BINNING_INDEX:   1
IM_URL:          sw00378559000msuni0339.fits
SUN_POSTN:       255.28d {+17h 01m 07s}  -22.75d {-22d 44' 51"}
SUN_DIST:        136.72 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.89d {+10h 35m 34s}   +4.84d {+04d 50' 09"}
MOON_DIST:       125.46 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  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:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 08 Dec 09 10:05:25 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     378559,   Seg_Num: 0
POINT_RA:         29.376d {+01h 57m 30s} (J2000)
POINT_DEC:       +16.897d {+16d 53' 49"} (J2000)
ROLL:            254.510d
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35731.03 SOD {09:55:31.03} UT,   333.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     281958936
X_OFFSET:        559 [pixels]
Y_OFFSET:        827 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       719
Y_GRB_POS:       987
BINNING_INDEX:   1
IM_URL:          sw00378559000msuni0339.fits
SUN_POSTN:       255.28d {+17h 01m 07s}  -22.75d {-22d 44' 51"}
SUN_DIST:        136.72 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.89d {+10h 35m 34s}   +4.84d {+04d 50' 15"}
MOON_DIST:       125.46 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.82,-43.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       33.23,  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 Circular #10255
A. de Ugarte Postigo (INAF-OAB), A.J. Castro-Tirado, J. Gorosabel, M. Jelinek (IAA-CSIC), P. Kubanek (IPL UV, IAA-CSIC), R. Cunniffe, S. Guziy (IAA-CSIC), P. Yock (Auckland Univ.), W.H. Allen (Vintage Lane Obs.), I. Bond (Massey Univ.), G. Christie (Stardome Obs.), report on behalf of a larger collaboration, report:
"We have observed the field of GRB091208B (Swift trigger 378559) using the 0.6m Yock-Allen robotic telescope (BOOTES-3) located in Bleinheim, New Zealand. Observations began at 05:50:04 UT (45 sec after the burst). There is a bright optical counterpart within the XRT error circle at coordinates (J2000.0 +/- 1"):
```
R.A.: 01:57:34.13
Dec.: +16:53:23.00
```
Further observations are ongoing."
GCN Circular #10256
C. Pagani (PSU), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), C. Gronwall (PSU), S. T. Holland (CRESST/USRA/GSFC), N. P. M. Kuin (MSSL), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), A. Rowlinson (U Leicester), M. Stamatikos (OSU/NASA/GSFC), G. Tagliaferri (INAF-OAB) and L. Vetere (PSU) report on behalf of the Swift Team:
At 09:49:57 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 091208B (trigger=378559). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 29.410, +16.883 which is
```
   RA(J2000) = 01h 57m 39s
   Dec(J2000) = +16d 52' 57"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 15 sec. The peak count rate was ~9100 counts/sec (15-350 keV), at ~8 sec after the trigger.
The XRT began observing the field at 09:51:53.1 UT, 115.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 29.3920, 16.8899 which is equivalent to:
```
   RA(J2000)  = 01h 57m 34.09s
   Dec(J2000) = +16d 53' 23.6"
```
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 66 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.85e+20 cm^-2, Kalberla et al. 2005), with an excess column of 3.3 (+1.52/-1.28) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 119 seconds after the BAT trigger. There is an afterglow in the rapidly available 2.7'x2.7' sub-image at
```
   RA(J2000)  =    01:57:34.06 = 29.39193 
   DEC(J2000) =   +16:53:22.7  = 16.88963  with a 90%-confidence
```
error radius of about 0.6 arc sec. This position is 0.67 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.9. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05. There is a bright afterglow candidate consistent with the XRT position.
Burst Advocate for this burst is C. Pagani (pagani 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:     Tue 08 Dec 09 10:16:48 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     378559,   Seg_Num: 0
GRB_RA:           29.3922d {+01h 57m 34.12s} (J2000),
                  29.5278d {+01h 58m 06.66s} (current),
                  28.7109d {+01h 54m 50.62s} (1950)
GRB_DEC:         +16.8896d {+16d 53' 22.5"} (J2000),
                 +16.9378d {+16d 56' 15.9"} (current),
                 +16.6462d {+16d 38' 46.4"} (1950)
GRB_ERROR:       10.0 [arcsec radius, statistical only]
GRB_MAG:         17.39 +/- 3.00 [mag]
FILTER:          10, White
IMG_START_DATE:  15173 TJD;   342 DOY;   09/12/08
IMG_START_TIME:  35520.00 SOD {09:52:00.00} UT,   122.0 [sec] since BAT Trigger Time
SUN_POSTN:       255.29d {+17h 01m 09s}  -22.75d {-22d 44' 53"}
SUN_DIST:        136.73 [deg]   Sun_angle= -8.9 [hr] (East of Sun)
MOON_POSTN:      158.99d {+10h 35m 58s}   +4.79d {+04d 47' 22"}
MOON_DIST:       125.56 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      144.85,-43.15 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       33.24,  4.57 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN Circular #10257
K.Noda, K.Kono, E.Sonoda, N.Ohmori, H.hayasi, A.Daikyuji, Y.Nisioka, M.Yamauchi (University of Miyazaki)
We have observed the field covering the error circle of GRB GRB091208B (Swift trigger 378559, GCN 10256, C. Pagani et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 09:59:30 UT, about 9.5 min after the Swift trigger time. We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, There is no new source at the reported position. (GCN 10255, A. de Ugarte Postigo et al.)
the upper limits are as follows:
```
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
09:59:30 10:00:00 1 15.9
09:59:30 10:47:23 37 17.3
---------------------------------------------------------------
```
GCN Circular #10258
M. Yoshida, D. Kuroda, K. Yanagisawa, Y. Shimizu, S. Nagayama, H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 091208B (Pagani et al., GCN 10256) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started at 09:57:03 2009-12-08 UT, 426s after the trigger. We detected the optical afterglow previously reported by de Ugarte Postigo et al. (GCN 10255) and Pagani et al. (GCN 10256) in all the three bands.
The preliminary photometry results of the OT are listed below. We used GSC2.3 catalog for flux calibration.
```
#PDAY    MID-UT    T-EXP       g'            Rc            Ic
------------------------------------------------------------------
0.00855  10:02:17  540.0  18.4 $B!^(B 0.2  17.6 $B!^(B 0.1  17.0 $B!^(B 0.2
0.01615  10:13:14  540.0  18.5 $B!^(B 0.2  18.1 $B!^(B 0.2  17.4 $B!^(B 0.2
------------------------------------------------------------------
```
GCN Circular #10259
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 466 s of XRT Photon Counting mode data and 1 UVOT images for GRB 091208B, 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 = 29.39223, +16.88965 which is equivalent to:
```
RA (J2000): 01h 57m 34.13s
Dec (J2000): +16d 53' 22.7"
```
with an uncertainty of 1.8 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 #10260
H. Nakajima, Y. Yatsu, Y.A. Mori, A. Endo, T. Shimokawabe, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 091208B (Pagani et al., GCN 10256) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope at Akeno, Japan. The observation started at 2009-12-08 09:50:45 UT, 48s after the trigger. We detected the optical afterglow (de Ugarte Postigo et al. GCN 10255, Pagani et al. GCN 10256, Yoshida et al. GCN 10258) in all the three bands.
The preliminary photometry results of the OT are listed below. We used GSC2.3 catalog for flux calibration.
```
 MID-UT    T-EXP    g'         Rc            Ic
------------------------------------------------------------------
 09:51:15  60.0   17.2 $B!^(B 0.2  16.1 $B!^(B 0.1  15.5 $B!^(B 0.1
------------------------------------------------------------------
```
GCN Circular #10262
Z. Cano, A. Melandri, C.G. Mundell (Liverpool JMU), A. Gomboc (U. Ljubljana), D. Bersier, N.R. Clay, S. Kobayashi, C.J. Mottram, R.J. Smith, I.A. Steele (Liverpool JMU), C. Guidorzi (U. Ferrara) report on behalf of a large collaboration:
The 2-m Faulkes Telescopes North and South robotically followed up GRB091208B (SWIFT trigger 378559; Pagani et al. GCN 10256) beginning 1.78 min after the GRB trigger time. We detect the optical afterglow in BRi' filters at the location reported by de Ugarte Postigo et al. (GCN 10255) and Pagani et al. (GCN 10256).
We derive the following preliminary magnitudes wrt USNOB1:
```
Filter    Mag     Merr      T-To (s)
-------------------------------------------
  R      17.75    0.02      572
  R      18.48    0.03     1656
  I      17.51    0.05     1036
  I      18.34    0.04     3749
```
From our observations we derive a power-law decay constant of ~ 0.6 for both filters.
We have not corrected our magnitudes for the small amount of foreground reddening along the line of sight (E(B-V) = 0.05, corresponding to Av = 0.17 (Schlegel et al. 1998)).
Observations and analysis are ongoing.
This message may be cited.
GCN Circular #10263
K. Wiersema, N. R. Tanvir (U. Leicester), A. Cucchiara (PSU), A. J. Levan (U. Warwick) & D. Fox (PSU) report:
We observed the afterglow of GRB 091208B (Pagani et al. GCN 10256; de Ugarte Postigo et al. GCN 10255) with the GMOS-N spectrograph on Gemini North, beginning at 11:17 UT on December 8. We use the R400 grism. The resulting spectrum covers the wavelength range 4000-8400 A and shows clear absorption lines of the MgII doublet (2796,2803), MgI (2853), FeI (2967), FeII (2586,2600) and MnII (2576,2594,2606) at a common redshift of z = 1.063.
We thank the Gemini-N staff, in particular K. Chiboucas, for performing this observation.
GCN Circular #10265
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), C. Pagani (PSU), 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 091208B (trigger #378559) (Pagani, et al., GCN Circ. 10256). The BAT ground- calculated position is RA, Dec = 29.411, 16.881 deg which is
```
    RA(J2000)  =  01h 57m 38.5s
    Dec(J2000) = +16d 52' 50.7"
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 10%.
The mask-weighted light curve shows two separated FRED peaks. The first at T0 was weaker and softer than the second at T+8 sec. T90 (15-350 keV) is 14.9 +- 3.7 sec (estimated error including systematics).
The time-averaged spectrum from T-0.2 to T+22.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.74 +- 0.11. The fluence in the 15-150 keV band was 3.3 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+8.1 sec in the 15-150 keV band was 15.2 +- 1.0 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/378559/BA/
GCN Circular #10266
S. McBreen (UCD/MPE) reports on behalf of the Fermi GBM Team:
"At 09:49:57.96 UT on 08 December 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 091208B (trigger 281958599 / 091208410) which was also detected by the Swift-BAT (Pagani et al. 2009, GCN 10256). The GBM on-ground location is consistent with the Swift position. This burst was also independently detected by INTEGRAL SPI-ACS.
The angle from the Fermi LAT boresight is 56 degrees. Moreover, this burst was bright enough to result in a Fermi spacecraft repointing maneuver.
The GBM light curve consists of two pulses with a duration (T90) of about 15 s (8-1000 keV). The time-averaged spectrum from T0-0.128 s to T0+14.592 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -1.48 (+0.05/-0.05) and the cutoff energy, parameterized as Epeak, is 144.20 (+18.00/-13.90) keV (CSTAT 829 for 604 d.o.f.).
The event fluence (8-1000 keV) in this time interval is (5.8 +/- 0.2)E-06 erg/cm^2. The 0.128 sec peak photon flux measured starting from T0+8.45 s in the 8-1000 keV band is 32.4 +/- 1.1 ph/s/cm^2.
A Band function fits the spectrum equally well (CSTAT 827 for 603 d.o.f.) with Epeak= 124.00 (+20.10/-19.40) keV, alpha = -1.44 (+0.07/-0.06) and beta = -2.32 (+0.19/-0.47).
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #10267
M. De Pasquale (MSSL/UCL) and C. Pagani (PSU) report on behalf of the Swift UVOT team.
The Swift UltraViolet/Optical Telescope (UVOT) began settled observations of the GRB 091208B (Swift BAT trigger number 378559; Pagani et al. GCN Circ. 10256) 119 s after the BAT trigger with an exposure in the UVOT white filter.
A new optical source is found at position RA, Dec = 29.39204, 16.88967, corresponding to
```
  RA  (J2000) =  01 57 34.09
  Dec (J2000) = +16 53 22.82
```
This is within 0.6 arseconds from the XRT enhanced position (Osborne et al., GCN Circ. 10259) and consistent with it. The detection is in all 3 filters UVOT used at early epoch.
The initial magnitudes are given below.
```
Filter  Time(s)       Mag      Err

wh      119-269      17.92    0.04

b       588-605      18.38    0.29

u       333-583      18.63    0.09
```
We caution that data analysis is slightly complicated by the presence of a dim source 3 arcsecond away from the afterglow.
The values quoted above are on the UVOT Photometric System (Poole et al., 2008, MNRAS 383,627). They are not corrected for the expected Galactic extinction, corresponding to a reddening of E(B-V)=0.05.
GCN Circular #10268
C. Pagani (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
We have analysed 3.6 ks of XRT data for GRB 091208B (Pagani et al. GCN Circ. 10256), from 132 s to 12.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 10259).
The light curve presents bumps and mini-flares and can be modelled with a power-law decay with a decay index of alpha=0.73 (+0.04, -0.05).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.32 (+0.18, -0.16). The best-fitting absorption column is 2.9 (+/-0.5) x 10^21 cm^-2, in excess of the Galactic value of 4.8 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 3.7 x 10^-11 (7.2 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 0.73, the count rate at T+24 hours will be 0.034 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x 10^-12 (2.5 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00378559.
This circular is an official product of the Swift-XRT team.
GCN Circular #10269
D. Xu (WIS, DARK/NBI), G. Leloudas, D. Malesani (DARK/NBI), P. Jakobsson (Univ. of Iceland), J. Lindberg, J. Andersen (NOT) report on behalf of a larger collaboration:
We observed the field of GRB091208B (Pagani et al. GCN 10256; de Ugarte Postigo et al. GCN 10255) at the Nordic Optical Telescope equipped with ALFOSC. The 2x300s frames were obtained starting at 20:46:43 UT on Nov. 28th, 10.9878 hr after the burst trigger.
The magnitude of the afterglow is R~20.9 with respect to stars in the USNO B1 catalog. Comparison with the measurement in Cano et al. (GCN 10262) indicates a general decay slope of ~0.6-~0.7 in the R band.
GCN Circular #10271
Adria Updike (Clemson University), Andrea Rossi (Tautenburg Obs.) and Jochen Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 091208B (Swift trigger 378559, Pagani et al., GCN #10256) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile).
First observations started at 01:07 UT on Dec 09, 15h17m after the GRB trigger, for a total integration time of 7.7 min in g'r'i'z' and 8min in JHK.
For the afterglow reported by Pagani et al. and de Ugarte Postigo et al. (GCN #10255) we estimate the following preliminary magnitudes (in the AB system):
```
g' = 22.64  +- 0.15
r' = 21.88  +- 0.14
i' = 21.65  +- 0.17
z' = 21.35  +- 0.17
J  = 20.61  +- 0.10
H  = 20.5   +- 0.3
K analysis on going
```
These magnitudes are in agreement with a afterglow at redshift z<3.5. After correction for the different filter and magnitude system, a comparison with other observation (Xu et al.,GCN #10269 and Cano et al., GCN #10262) confirms that the afterglow is decaying with the slope of 0.6-0.7 reported by Xu et al. .
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars. The errors take in account zero point uncertainties. Magnitudes are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.05 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #10272
D. A. Perley (UC Berkeley), J. X. Prochaska (UCSC), P. Kalas, A. Howard, M. Fitzgerald, G. Marcy, and J. Graham (UCB) report:
Starting at 10:58:17 UT on December 8 we initiated a single 1200 second exposure of the afterglow of GRB 091208B (GCN 12055, de Ugarte Postigo et al.; GCN 10256, Pagani et al.) with HIRES-r on the 10m Keck I telescope. Consistent with the result of Wiersema et al. (GCN 10263), we detect absorption lines from MgII and MnII at a redshift of z=1.0633+/-0.0003. Additionally, we detect fine-structure transitions of FeII confirming that this is the redshift of the GRB.
GCN Circular #10273
M.Andreev, A.Sergeev, N.Parakhin, N.Karpov (Terskol Branch of Institute of Astronomy), Yu. Kuznietsova (Main Astronomical Observatory NASU), V.Petkov (Baksan Neutrino Observatory INR) and A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed the field of the Swift GRB 091208B (Pagani et al. GCN 10256) with the Z-600 telescope of Mt.Terskol observatory in R-filter on Dec. 08 starting at (UT) 15:40. In combined images we detect the optical afterglow (Ugarte Postigo et al. GCN 10255, Pagani et al. GCN 10256).
Preliminary photometry is based on the USNO-B1.0 reference star #1069-0020318 assuming R2=17.47:
```
UT     Filter, Exposure, mag.  err.
(mid)             (s)

16:10  R  30x120  20.15  0.25
18:11  R  30x120  20.60  0.25
19:11  R  30x120  20.9    0.3
20:19  R  30x120  21.0    0.3
```
Combined image can be found in http://grb.rssi.ru/GRB091208B/GRB091208B_Terskol600_R.jpg
GCN Circular #10275
K. Kinugasa, S. Honda, H. Takahashi, H. Taguchi, O. Hashimoto (Gunma Astronomical Observatory) report:
The position of GRB 091208B (Pagani et al., GCN 10256) was observed with the 150 cm telescope of Gunma Astronomical Observatory. Starting at 10:21:09 UT on Dec.8 ( 0.52 hours after the trigger), both Rc and Ic frames were acquired for sets of 3 x 2-min and 5 x 5-min exposures.
We detected the optical counterpart (e.g., de Ugarte Postigo et al., GCN 10255; Yoshida et al. GCN 10258) in all frames. We estimated the Rc and Ic magnitudes relative to USNO-B1.0 R2 and I magnitudes, respectively.
```
mid-UT     T0+(d)     exp                mag.
-----------------------------------------------------
10:50:45   0.01796    3x2min, 5x3min     Rc=18.8+-0.1
11:07:20   0.02273    3x2min, 5x3min     Ic=18.4+-0.1
-----------------------------------------------------
```
The R magnitude is consistent with the fading trend of a power-law slope of ~0.7 from the other optical observations (e.g. Cano et al. GCN 10262; Xu et al. GCN 10269; Nakajima et al. GCN 10260).
GCN Circular #10279
L.P. Xin, S. B, Qian, Y.L. Qiu, J. Wang, J.Y. Wei, W. K. Zheng, J. S. Deng, and J. Y. Hu on behalf of EAFON report:
We observed the optical afterglow of GRB 091208B (Pagani et al. GCN 10256) with Xinglong TNT telescope from Nov. 8th, 10:12:31.6(UT), 23 min after the burst. The optical counterpart was clearly detected in our images. The brightness was estimated to be about R~18.5 relative to the USNO-B1.0 R2 mag, at the meam time of 30 min after the burst.
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for more information about Xinglong GRBs Follow-up observations, please visit the web-site http://www.xinglong-naoc.org/grb/
GCN Report 266.1
GCN_Report 266.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_266_1.pdf by C. Pagani at PSU titled: "Final Swift Observations on GRB 091208B"
1010.1436 from 8 Oct 10
C. W. Akerlof et al.: Searching for Needles in Haystacks - Looking for GRB gamma-rays with the Fermi/LAT Detector
Since the launch of the Fermi~Gamma-ray~Space~Telescope on June 11, 2008, 55 gamma-ray bursts (GRBs) have been observed at coordinates that fall within 66^\circ of the Fermi Large Area Telescope (LAT) boresight with precise localizations provided by the NASA Swift mission or other satellites. Imposing selection cuts to exclude low Galactic latitudes and high zenith angles reduces the sample size to 41. Using matched filter techniques, the Fermi/LAT photon data for these fields have been examined for evidence of bursts that have so far evaded detection at energies above 100 MeV. Following comparisons with similar random background fields, two events, GRB 080905A and GRB 091208B, stand out as excellent candidates for such an identification. After excluding the six bright bursts previously reported by the LAT team, the remaining 35 events exhibit an excess of LAT "diffuse" photons with a statistical significance greater than 2 sigma, independent of the matched filter analysis. After accounting for the total number of photons in the well-localized fields and including estimates of detection efficiency, one concludes that somewhere in the range of 11% to 19% of all GRBs within the LAT field of view illuminate the detector with two or more energetic photons. These are the most stringent estimates of the high energy photon content of GRBs to date. The two new events associated with high energy photon emission have similar ratios of high to low energy fluences as observed previously. This separates them from bursts with similar low energy fluences by a factor of ten, suggesting a distinct class of events rather than a smooth continuum.

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Jochen Greiner, last update: 03-Feb-2010 [Disclaimer]