Gamma-ray Burst 091109B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:29:51 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      49
TRIGGER_NUM:     279494922
GRB_RA:          253.533d {+16h 54m 08s} (J2000),
                 253.616d {+16h 54m 28s} (current),
                 253.115d {+16h 52m 28s} (1950)
GRB_DEC:         +39.717d {+39d 42' 60"} (J2000),
                 +39.701d {+39d 42' 04"} (current),
                 +39.796d {+39d 47' 47"} (1950)
GRB_ERROR:       9.20 [deg radius, statistical plus systematic]
GRB_INTEN:       443 [cnts/sec]
DATA_SIGNIF:     14.50 [sigma]
INTEG_TIME:      0.512 [sec]
GRB_DATE:        15144 TJD;   313 DOY;   09/11/09
GRB_TIME:        77320.00 SOD {21:28:40.00} UT
GRB_PHI:          15.00 [deg]
GRB_THETA:        20.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO:      1.00
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       1,1,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       225.15d {+15h 00m 36s}  -17.08d {-17d 05' 04"}
SUN_DIST:         62.69 [deg]   Sun_angle= -1.9 [hr] (East of Sun)
MOON_POSTN:      142.26d {+09h 29m 02s}  +12.44d {+12d 26' 26"}
MOON_DIST:        97.82 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:       63.55, 38.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      242.71, 61.60 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 219.00,14.93 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:30:02 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     279494922
GRB_RA:          251.480d {+16h 45m 55s} (J2000),
                 251.557d {+16h 46m 14s} (current),
                 251.089d {+16h 44m 21s} (1950)
GRB_DEC:         +43.340d {+43d 20' 24"} (J2000),
                 +43.323d {+43d 19' 21"} (current),
                 +43.429d {+43d 25' 46"} (1950)
GRB_ERROR:       5.72 [deg radius, statistical only]
DATA_SIGNIF:     16.50 [sigma]
DATA_INTERVAL:   0.512 [sec]
GRB_DATE:        15144 TJD;   313 DOY;   09/11/09
GRB_TIME:        77320.00 SOD {21:28:40.00} UT
GRB_PHI:           7.00 [deg]
GRB_THETA:        17.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       225.15d {+15h 00m 36s}  -17.08d {-17d 05' 04"}
SUN_DIST:         65.09 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
MOON_POSTN:      142.26d {+09h 29m 02s}  +12.44d {+12d 26' 23"}
MOON_DIST:        94.99 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:       68.14, 40.54 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      237.29, 64.69 [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/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:49:16 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     375409,   Seg_Num: 0
GRB_RA:          112.717d {+07h 30m 52s} (J2000),
                 112.773d {+07h 31m 06s} (current),
                 112.430d {+07h 29m 43s} (1950)
GRB_DEC:         -54.080d {-54d 04' 48"} (J2000),
                 -54.102d {-54d 06' 05"} (current),
                 -53.974d {-53d 58' 24"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       631 [cnts]    Image_Peak=63 [image_cnts]
TRIGGER_DUR:     0.064 [sec] 
TRIGGER_INDEX:   10427     E_range: 50-350 keV
BKG_INTEN:       24341 [cnts]
BKG_TIME:        78530.75 SOD {21:48:50.75} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15144 TJD;   313 DOY;   09/11/09
GRB_TIME:        78542.91 SOD {21:49:02.91} UT
GRB_PHI:         -174.91 [deg]
GRB_THETA:        31.95 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     27.78 [sigma]
IMAGE_SIGNIF:    7.05 [sigma]
MERIT_PARAMS:     +1  +0  +0  -4  +3  -3  +0  +0  -2  +0 
SUN_POSTN:       225.16d {+15h 00m 39s}  -17.09d {-17d 05' 18"}
SUN_DIST:         88.59 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.44d {+09h 29m 45s}  +12.37d {+12d 21' 57"}
MOON_DIST:        71.08 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      142.42,-73.39 [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 = 119.38,-12.47 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:50:27 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.719d {+07h 30m 53s} (J2000)
POINT_DEC:       -54.075d {-54d 04' 30"} (J2000)
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78621.06 SOD {21:50:21.06} UT,   78.1 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:52:55 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     375409,   Seg_Num: 0
GRB_RA:          112.717d {+07h 30m 52s} (J2000),
                 112.773d {+07h 31m 06s} (current),
                 112.430d {+07h 29m 43s} (1950)
GRB_DEC:         -54.080d {-54d 04' 48"} (J2000),
                 -54.102d {-54d 06' 05"} (current),
                 -53.974d {-53d 58' 24"} (1950)
GRB_DATE:        15144 TJD;   313 DOY;   09/11/09
GRB_TIME:        78543.15 SOD {21:49:03.15} UT
TRIGGER_INDEX:   10427
GRB_PHI:         -174.91 [deg]
GRB_THETA:        31.95 [deg]
DELTA_TIME:      39.00 [sec]
TRIGGER_DUR:     0.064 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     27.78 [sigma]
IMAGE_SIGNIF:    7.05 [sigma]
LC_URL:          sw00375409000msb.lc
SUN_POSTN:       225.17d {+15h 00m 40s}  -17.09d {-17d 05' 20"}
SUN_DIST:         88.59 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.47d {+09h 29m 53s}  +12.35d {+12d 21' 07"}
MOON_DIST:        71.08 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      142.42,-73.39 [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 = 119.38,-12.47 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:53:26 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.719d {+07h 30m 53s} (J2000)
POINT_DEC:       -54.076d {-54d 04' 32"} (J2000)
POINT_ROLL:      117.907d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78626.66 SOD {21:50:26.66} UT,   83.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.768
N_STARS:         120
X_OFFSET:        498 [pixels]
Y_OFFSET:        555 [pixels]
X_MAX:           1457 [pixels]
Y_MAX:           1514 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00375409000msufc0083.fits
SUN_POSTN:       225.17d {+15h 00m 40s}  -17.09d {-17d 05' 21"}
SUN_DIST:         88.59 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.47d {+09h 29m 54s}  +12.35d {+12d 20' 60"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:53:53 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.719d {+07h 30m 53s} (J2000)
POINT_DEC:       -54.076d {-54d 04' 32"} (J2000)
POINT_ROLL:      117.907d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78626.66 SOD {21:50:26.66} UT,   83.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.768
N_STARS:         120
X_OFFSET:        498 [pixels]
Y_OFFSET:        555 [pixels]
X_MAX:           1457 [pixels]
Y_MAX:           1514 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00375409000msufc0083.fits
SUN_POSTN:       225.17d {+15h 00m 40s}  -17.09d {-17d 05' 21"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.48d {+09h 29m 55s}  +12.35d {+12d 20' 53"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.38 [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:     Mon 09 Nov 09 21:53:26 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.719d {+07h 30m 53s} (J2000)
POINT_DEC:       -54.076d {-54d 04' 32"} (J2000)
POINT_ROLL:      117.907d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78626.66 SOD {21:50:26.66} UT,   83.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.768
N_STARS:         120
X_OFFSET:        498 [pixels]
Y_OFFSET:        555 [pixels]
X_MAX:           1457 [pixels]
Y_MAX:           1514 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00375409000msufc0083.fits
SUN_POSTN:       225.17d {+15h 00m 40s}  -17.09d {-17d 05' 21"}
SUN_DIST:         88.59 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.47d {+09h 29m 54s}  +12.35d {+12d 20' 60"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 21:54:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.719d {+07h 30m 53s} (J2000)
POINT_DEC:       -54.076d {-54d 04' 32"} (J2000)
ROLL:            117.907d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78626.66 SOD {21:50:26.66} UT,   83.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     279496231
X_OFFSET:        817 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       977
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00375409000msuni0089.fits
SUN_POSTN:       225.17d {+15h 00m 40s}  -17.09d {-17d 05' 22"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.49d {+09h 29m 57s}  +12.34d {+12d 20' 41"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.38 [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:     Mon 09 Nov 09 21:54:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.719d {+07h 30m 53s} (J2000)
POINT_DEC:       -54.076d {-54d 04' 32"} (J2000)
ROLL:            117.907d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78626.66 SOD {21:50:26.66} UT,   83.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     279496231
X_OFFSET:        817 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       977
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00375409000msuni0089.fits
SUN_POSTN:       225.17d {+15h 00m 40s}  -17.09d {-17d 05' 22"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.48d {+09h 29m 56s}  +12.35d {+12d 20' 45"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.38 [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:     Mon 09 Nov 09 21:58:12 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     375409,   Seg_Num: 0
GRB_RA:          112.7328d {+07h 30m 55.87s} (J2000),
                 112.7892d {+07h 31m 09.40s} (current),
                 112.4465d {+07h 29m 47.16s} (1950)
GRB_DEC:         -54.0890d {-54d 05' 20.3"} (J2000),
                 -54.1102d {-54d 06' 36.8"} (current),
                 -53.9821d {-53d 58' 55.4"} (1950)
GRB_ERROR:       5.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78632.00 SOD {21:50:32.00} UT,   89.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 24"}
SUN_DIST:         88.58 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.52d {+09h 30m 04s}  +12.33d {+12d 19' 54"}
MOON_DIST:        71.08 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.93,-16.25 [deg] galactic lon,lat of the burst
ECL_COORDS:      142.46,-73.39 [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:     Mon 09 Nov 09 22:00:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 41"} (J2000)
POINT_ROLL:      117.912d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78839.19 SOD {21:53:59.19} UT,   296.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.241
N_STARS:         184
X_OFFSET:        258 [pixels]
Y_OFFSET:        315 [pixels]
X_MAX:           1697 [pixels]
Y_MAX:           1754 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00375409000msufc0296.fits
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 26"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.54d {+09h 30m 10s}  +12.32d {+12d 19' 20"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 22:00:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 41"} (J2000)
POINT_ROLL:      117.912d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78839.19 SOD {21:53:59.19} UT,   296.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.241
N_STARS:         184
X_OFFSET:        258 [pixels]
Y_OFFSET:        315 [pixels]
X_MAX:           1697 [pixels]
Y_MAX:           1754 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00375409000msufc0296.fits
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 26"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.54d {+09h 30m 10s}  +12.32d {+12d 19' 20"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 22:01:14 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 41"} (J2000)
POINT_ROLL:      117.912d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78839.19 SOD {21:53:59.19} UT,   296.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.241
N_STARS:         184
X_OFFSET:        258 [pixels]
Y_OFFSET:        315 [pixels]
X_MAX:           1697 [pixels]
Y_MAX:           1754 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00375409000msufc0296.fits
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 26"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.55d {+09h 30m 11s}  +12.32d {+12d 19' 12"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [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:     Mon 09 Nov 09 22:01:42 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     375409,   Seg_Num: 0
GRB_RA:          112.7348d {+07h 30m 56.35s} (J2000),
                 112.7912d {+07h 31m 09.88s} (current),
                 112.4485d {+07h 29m 47.64s} (1950)
GRB_DEC:         -54.0895d {-54d 05' 22.2"} (J2000),
                 -54.1107d {-54d 06' 38.6"} (current),
                 -53.9825d {-53d 58' 57.1"} (1950)
GRB_ERROR:       3.6 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78632.00 SOD {21:50:32.00} UT,   89.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 27"}
SUN_DIST:         88.58 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.55d {+09h 30m 12s}  +12.32d {+12d 19' 05"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.93,-16.25 [deg] galactic lon,lat of the burst
ECL_COORDS:      142.47,-73.39 [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:     Mon 09 Nov 09 22:02:01 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 41"} (J2000)
ROLL:            117.912d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78839.19 SOD {21:53:59.19} UT,   296.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     279496444
X_OFFSET:        817 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       977
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00375409000msuni0302.fits
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 27"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.55d {+09h 30m 13s}  +12.32d {+12d 19' 01"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [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:     Mon 09 Nov 09 22:02:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 41"} (J2000)
ROLL:            117.912d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  78839.19 SOD {21:53:59.19} UT,   296.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     279496444
X_OFFSET:        817 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       977
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00375409000msuni0302.fits
SUN_POSTN:       225.17d {+15h 00m 41s}  -17.09d {-17d 05' 27"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.56d {+09h 30m 14s}  +12.32d {+12d 18' 56"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [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:     Mon 09 Nov 09 22:07:11 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 39"} (J2000)
POINT_ROLL:      117.913d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  79419.74 SOD {22:03:39.74} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.075
N_STARS:         190
X_OFFSET:        258 [pixels]
Y_OFFSET:        315 [pixels]
X_MAX:           1697 [pixels]
Y_MAX:           1754 [pixels]
DET_THRESH:      21
PHOTO_THRESH:    12
SL_URL:          sw00375409000msufc0876.fits
SUN_POSTN:       225.18d {+15h 00m 42s}  -17.09d {-17d 05' 30"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.60d {+09h 30m 24s}  +12.30d {+12d 17' 49"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 22:07:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 39"} (J2000)
POINT_ROLL:      117.913d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  79419.74 SOD {22:03:39.74} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.075
N_STARS:         190
X_OFFSET:        258 [pixels]
Y_OFFSET:        315 [pixels]
X_MAX:           1697 [pixels]
Y_MAX:           1754 [pixels]
DET_THRESH:      21
PHOTO_THRESH:    12
SL_URL:          sw00375409000msufc0876.fits
SUN_POSTN:       225.18d {+15h 00m 42s}  -17.09d {-17d 05' 31"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.61d {+09h 30m 26s}  +12.29d {+12d 17' 42"}
MOON_DIST:        71.06 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [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:     Mon 09 Nov 09 22:07:11 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 39"} (J2000)
POINT_ROLL:      117.913d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  79419.74 SOD {22:03:39.74} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.075
N_STARS:         190
X_OFFSET:        258 [pixels]
Y_OFFSET:        315 [pixels]
X_MAX:           1697 [pixels]
Y_MAX:           1754 [pixels]
DET_THRESH:      21
PHOTO_THRESH:    12
SL_URL:          sw00375409000msufc0876.fits
SUN_POSTN:       225.18d {+15h 00m 42s}  -17.09d {-17d 05' 30"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.60d {+09h 30m 24s}  +12.30d {+12d 17' 49"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 09 Nov 09 22:09:26 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 39"} (J2000)
ROLL:            117.913d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  79419.74 SOD {22:03:39.74} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     279497024
X_OFFSET:        817 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       977
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00375409000msuni0882.fits
SUN_POSTN:       225.18d {+15h 00m 43s}  -17.09d {-17d 05' 32"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.62d {+09h 30m 29s}  +12.29d {+12d 17' 18"}
MOON_DIST:        71.06 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [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:     Mon 09 Nov 09 22:09:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     375409,   Seg_Num: 0
POINT_RA:        112.714d {+07h 30m 51s} (J2000)
POINT_DEC:       -54.078d {-54d 04' 39"} (J2000)
ROLL:            117.913d
IMG_START_DATE:  15144 TJD;   313 DOY;   09/11/09
IMG_START_TIME:  79419.74 SOD {22:03:39.74} UT,   876.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     279497024
X_OFFSET:        817 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       977
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00375409000msuni0882.fits
SUN_POSTN:       225.18d {+15h 00m 43s}  -17.09d {-17d 05' 32"}
SUN_DIST:         88.60 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      142.63d {+09h 30m 30s}  +12.29d {+12d 17' 13"}
MOON_DIST:        71.06 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      265.91,-16.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      142.41,-73.39 [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 Circular #10148
S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), M. A. Stark (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 21:49:03 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 091109B (trigger=375409). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 112.717, -54.080 which is
```
   RA(J2000)  =  07h 30m 52s
   Dec(J2000) = -54d 04' 48"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike with a duration of about 0.4 sec. The peak count rate was ~30,000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 21:50:21.1 UT, 78.1 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 112.7349, -54.0896 which is equivalent to:
```
   RA(J2000)  = 07h 30m 56.39s
   Dec(J2000) = -54d 05' 22.7"
```
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 51 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 consistent with the Galactic value of 9.23e+20 cm^-2 (Kalberla et al. 2005).
UVOT took a finding chart exposure of 250 seconds with the U filter starting 296 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The 3-sigma upper limit is 20.3 mag. The coverage of the XRT error circle by the 8'x8' region for the list of sources generated on-board is uncertain because the large number of sources filled the available telemetry. No correction has been made for the expected extinction corresponding to E(B-V) of 0.17.
Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.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 Circular #10149
B. E. Schaefer (Louisiana State), E.S. Rykoff (UCSB), T. Guver (U Arizona), H. Flewelling (IfA/Hawaii), S. B. Pandey (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 091109B (Swift trigger 375409; S. R. Oates et al., GCN 10148), producing images beginning 9.4 s after the GCN notice time. An automated response took the first image at 21:49:24.5 UT, 21.6 s after the burst, under excellent conditions. We took 10 5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going.
Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle or the XRT error circle, for both single images and coadding into sets of 10; the field is not crowded. Individual images have limiting magnitudes ranging from 15.9-17.0; we set the following specific limits.
```
start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
21:49:24.5   21:49:29.5         5     16.0           21.6       N
21:49:24.4   21:50:40.5        76     16.9           21.5       Y
```
GCN Circular #10150
M. Jel=C4=82=C2=ADnek (IAA-CSIC), A. de Ugarte Postigo (INAF-OAB), R. Fel= letti, L. Hanlon (UCD Dublin), H. Van Heerden (UOVS, Bloemfontein), P. Kub=C4=82=C4= =84nek (IPL UV, IAA-CSIC) reports on behalf of a large collaboration:
Watcher telescope, located at Boyden Observatory, South Africa, observed autonomously GRB 091109B (S. R. Oates et al., GCN 10148). We obtained a set of 5s exposures in clear filter, starting 78s after the GRB (65s after the notice). We see no new sources in the XRT error box down to the single-image limiting magnitude of 16.5. Coaddition of first 120s (mean exposure time 153s after the GRB) of imaging data improves this limit to ~17.7 calibrated against field USNO-A2.0 R-band stars. Those results are consistent with ROTSE-III non-detection (Schaefer et al. GCN 10149).
We note that there is a R~15.3 galaxy 8" North-West of the XRT position, posibly the host of this short GRB.
Further observations are ongoing. This message can be quoted.
GCN Circular #10151
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1173 s of XRT Photon Counting mode data and 1 UVOT images for GRB 091109B, 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 = 112.73603, -54.08983 which is equivalent to:
```
RA (J2000): 07h 30m 56.65s
Dec (J2000): -54d 05' 23.4"
```
with an uncertainty of 2.8 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 #10153
E. Berger (Harvard), K. Covey (Cornell), A. A. West, J. M. Andersen (BU), and M. McDonald (U. Maryland, College Park) report:
"We observed the XRT error circle (GCN #10151) of the short GRB 091109b (GCN #10152) with IMACS on the Magellan/Baade 6.5-m telescope starting on 2009 Nov. 10.167 UT (6.2 hours after the burst). In a 1200-sec stacked R-band image we find no optical sources within the XRT error circle to a 3-sigma limit of R~23 mag in comparison to several nearby stars in the USNO-B catalog. We further note that the object claimed to be a galaxy north-west of the XRT position (GCN #10150) appears to be resolved into two point sources in our image (with a seeing of about 1.1 arcsec)."
GCN Circular #10154
A.J. Levan (Warwick), N.R. Tanvir (Leicester), J. Hjorth, D. Malesani (DARK/NBI), A. de Ugarte Postigo, P. D'Avanzo (INAF-OAB) report on behalf of a larger collaboration:
We observed the location of the short GRB 091109B (Oates et al. GCNC 10148), with the VLT/FORS2. Observations began at 03:34 UT, approximately 5.7 hours after the burst. Within the X-ray localisation (Evans et al. GCNC 10151) we identify a faint source (Source A) at:
```
RA: 07:30:56.61
Dec: -54:05:22.85
```
We also identify a second, fainter source (Source B) just outside the X-ray localisation, at:
```
RA: 07:30:56.46
Dec: -54:05:25.56
```
Both positions have errors of ~0.5" in each axis.
Source A has R~25, and appears pointlike. At this stage we cannot make any claim of variability in either source A or B, although further observation are planned.
Additionally, we note that the apparently extended object to the NW is actually a blend of two stars, and a possible galaxy, rather than a single object, and hence its relation to GRB 091109B is currently unclear.
We thank P. Lyman and the staff of VLT for their assistance with these observations.
GCN Circular #10155
K.L. Page (U. Leicester) and S.R. Oates (UCL-MSSL) report on behalf of the Swift-XRT team:
We have analysed 9.7 ks of XRT data for GRB 091109B (Oates et al. GCN Circ. 10148), from 86 s to 22.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 10151).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.62 (+0.11, -0.10). Although there is some evidence that there may be a steep, shallow, normal trend in the light-curve, as is often seen, there are not enough data points to warrant such additional modelling at this time.
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.0 (+0.5, -0.4). The best-fitting absorption column is 1.2 (+1.4, -0.1) x 10^21 cm^-2, in excess of the Galactic value of 9.2 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 3.8 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 0.62, the count rate at T+24 hours will be 2.4 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.1 x 10^-14 (1.2 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00375409.
This circular is an official product of the Swift-XRT team.
GCN Circular #10156
D. Malesani (DARK/NBI), A. de Ugarte Postigo (INAF/OABr), A. J. Levan (Univ. Warwick), N. R. Tanvir (Univ. Leicester), J. Hjorth (DARK/NBI), P. D'Avanzo (INAF/Brera), report on behalf of a larger collaboration:
Following the observations of GRB 091109B (Oates et al., GCN 10148) with the VLT reported by Levan et al. (GCN 10154), we obtained a further epoch of R-band imaging with mean time Nov 10.33 UT (10.22 hr after the burst), using the same instrument and configuration.
Source "A" by Levan et al. (GCN 10154) is still detected, and decayed by 1.0+-0.3 mag during this time interval, implying a decay index of alpha = 1.7+-0.5. We hence conclude that the source is indeed the afterglow of GRB 091109B.
We acknowledge excellent support from the ESO staff at Paranal, in particular Alain Smette and Paul Lynam.
GCN Circular #10157
S. R. Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091109B 84s after the BAT trigger (Oates et al., GCN 10148). We do not detect any source at the enhanced Swift XRT position (Evans et al. GCN 10151) and at the location of source A detected by the VLT (Levan et al. GCN 10154, Malesani et al. GCN 10156)
The 3-sigma upper limits for the finding chart exposures (FC) and summed images are:
```
Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white (FC)  84     234       147         > 21.25
u     (FC)  296    546       246         > 20.29
white       577    18629     1313        > 22.09
v           627    11274     1172        > 20.96
b           553    17890     1337        > 21.78
u           701    23171     1761        > 21.61
uvw1        677    22710     1988        > 21.44
uvm2        652    12179     1160        > 20.87
uvw2        603    7050      471         > 20.52
-------------------------------------------------------------
```
The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.17 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular #10168
M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), K. Yamaoka (Aoyama Gakuin U.), S. Sugita (Nagoya U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.), N. Ohmori, E. Sonoda, K. Kono, H. Hayashi, A. Daikyuji, Y. Nishioka, K. Noda, M. Yamauchi (Univ. of Miyazaki), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), W. Iwakiri, M. Tashiro, Y. Terada, A. Endo, K. Onda, T. Sugasahara (Saitama U.), Y. Urata, H.M Lin (NCU), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report:
The short GRB 091109B (Swift/BAT trigger #375409 ; Oates et al., GCN 10148) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2009-11-09 21:49:02.83 UT (=T0).
The observed light curve shows a single peak starting at T0+0.3s, ending at T0+0.6s with a duration (T90) of about 0.19 seconds. The fluence in 100 - 1000 keV was 9.98(-3.69,+0.72) x 10^-7 erg/cm^2. The 1-s peak flux measured from T0 was 1.75(-0.59,+0.14) photons/ cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0s to T0+1s is well fitted by a power-law with exponential cutoff model:
```
   dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
   alpha       0.91(-0.78,+0.42), and
   Epeak       1330(-610,+1120) keV (chi^2/d.o.f. = 24.6/24).
```
All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
GCN Report 259.1
GCN_Report 259.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_259_1.pdf by S.R. Oates at MSSL-UCL titled: "Swift Observations on GRB 091109B"

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Jochen Greiner, last update: 27-Nov-2009 [Disclaimer]