Gamma-ray Burst 151001A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:04:49 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     657286,   Seg_Num: 0
GRB_RA:          233.731d {+15h 34m 55s} (J2000),
                 233.919d {+15h 35m 41s} (current),
                 233.134d {+15h 32m 32s} (1950)
GRB_DEC:         +10.971d {+10d 58' 16"} (J2000),
                 +10.919d {+10d 55' 10"} (current),
                 +11.137d {+11d 08' 13"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3656 [cnts]    Image_Peak=278 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       19402 [cnts]
BKG_TIME:        54248.78 SOD {15:04:08.78} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17296 TJD;   274 DOY;   15/10/01
GRB_TIME:        54262.93 SOD {15:04:22.93} UT
GRB_PHI:         178.21 [deg]
GRB_THETA:         2.41 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     22.13 [sigma]
IMAGE_SIGNIF:    11.00 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +0 -66  +0 
SUN_POSTN:       187.46d {+12h 29m 50s}   -3.22d {-03d 13' 13"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.60d {+03h 42m 23s}  +15.28d {+15d 16' 52"}
MOON_DIST:       153.75 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.18, 48.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      228.24, 29.30 [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 = 342.73,14.09 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=465404666).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:04:58 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     465404666
GRB_RA:          238.900d {+15h 55m 36s} (J2000),
                 239.085d {+15h 56m 20s} (current),
                 238.312d {+15h 53m 15s} (1950)
GRB_DEC:         +12.333d {+12d 19' 60"} (J2000),
                 +12.288d {+12d 17' 17"} (current),
                 +12.478d {+12d 28' 42"} (1950)
GRB_ERROR:       17.87 [deg radius, statistical plus systematic]
GRB_INTEN:       60 [cnts/sec]
DATA_SIGNIF:     5.40 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        17296 TJD;   274 DOY;   15/10/01
GRB_TIME:        54262.41 SOD {15:04:22.41} UT
GRB_PHI:          60.00 [deg]
GRB_THETA:        20.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.44
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      93%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       187.46d {+12h 29m 50s}   -3.22d {-03d 13' 14"}
SUN_DIST:         53.58 [deg]   Sun_angle= -3.4 [hr] (East of Sun)
MOON_POSTN:       55.60d {+03h 42m 24s}  +15.28d {+15d 16' 53"}
MOON_DIST:       152.22 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       23.32, 44.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      233.52, 31.92 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn151001628/quicklook/glg_lc_medres34_bn151001628.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 23.63,-14.30 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=657286).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:05:26 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     465404666
GRB_RA:          231.480d {+15h 25m 55s} (J2000),
                 231.667d {+15h 26m 40s} (current),
                 230.886d {+15h 23m 33s} (1950)
GRB_DEC:         +12.130d {+12d 07' 48"} (J2000),
                 +12.076d {+12d 04' 32"} (current),
                 +12.305d {+12d 18' 16"} (1950)
GRB_ERROR:       10.52 [deg radius, statistical only]
DATA_SIGNIF:     10.40 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        17296 TJD;   274 DOY;   15/10/01
GRB_TIME:        54262.41 SOD {15:04:22.41} UT
GRB_PHI:          40.00 [deg]
GRB_THETA:        22.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       187.46d {+12h 29m 50s}   -3.22d {-03d 13' 14"}
SUN_DIST:         46.52 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:       55.60d {+03h 42m 25s}  +15.28d {+15d 16' 56"}
MOON_DIST:       152.37 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.13, 50.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      225.44, 29.81 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn151001628/quicklook/glg_lc_medres34_bn151001628.gif
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=657286).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:06:35 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     465404666
GRB_RA:          233.220d {+15h 32m 53s} (J2000),
                 233.409d {+15h 33m 38s} (current),
                 232.620d {+15h 30m 29s} (1950)
GRB_DEC:         +10.360d {+10d 21' 36"} (J2000),
                 +10.308d {+10d 18' 27"} (current),
                 +10.528d {+10d 31' 40"} (1950)
GRB_ERROR:       6.09 [deg radius, statistical only]
DATA_SIGNIF:     11.50 [sigma]
DATA_INTERVAL:   9.216 [sec]
GRB_DATE:        17296 TJD;   274 DOY;   15/10/01
GRB_TIME:        54262.41 SOD {15:04:22.41} UT
GRB_PHI:          46.00 [deg]
GRB_THETA:        23.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41531 (Gnd S/W Version number)
SUN_POSTN:       187.46d {+12h 29m 51s}   -3.22d {-03d 13' 15"}
SUN_DIST:         47.70 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.62d {+03h 42m 28s}  +15.28d {+15d 17' 03"}
MOON_DIST:       154.32 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       17.01, 48.51 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      227.88, 28.58 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn151001628/quicklook/glg_lc_medres34_bn151001628.gif
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=657286).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:08:33 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.738d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 18"} (J2000)
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54326.91 SOD {15:05:26.91} UT,   64.0 [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:     Thu 01 Oct 15 15:10:13 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     657286,   Seg_Num: 0
GRB_RA:          233.731d {+15h 34m 55s} (J2000),
                 233.919d {+15h 35m 41s} (current),
                 233.134d {+15h 32m 32s} (1950)
GRB_DEC:         +10.971d {+10d 58' 16"} (J2000),
                 +10.919d {+10d 55' 10"} (current),
                 +11.137d {+11d 08' 13"} (1950)
GRB_DATE:        17296 TJD;   274 DOY;   15/10/01
GRB_TIME:        54262.93 SOD {15:04:22.93} UT
TRIGGER_INDEX:   146
GRB_PHI:         178.21 [deg]
GRB_THETA:         2.41 [deg]
DELTA_TIME:      25.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     22.13 [sigma]
IMAGE_SIGNIF:    11.00 [sigma]
LC_URL:          sw00657286000msb.lc
SUN_POSTN:       187.46d {+12h 29m 51s}   -3.22d {-03d 13' 19"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.65d {+03h 42m 37s}  +15.29d {+15d 17' 26"}
MOON_DIST:       153.73 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.18, 48.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      228.24, 29.30 [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 = 342.73,14.09 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:10:40 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.738d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 19"} (J2000)
POINT_ROLL:      255.510d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54330.25 SOD {15:05:30.25} UT,   67.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.127
N_STARS:         36
X_OFFSET:        529 [pixels]
Y_OFFSET:        532 [pixels]
X_MAX:           1488 [pixels]
Y_MAX:           1491 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00657286000msufc0067.fits
SUN_POSTN:       187.46d {+12h 29m 51s}   -3.22d {-03d 13' 19"}
SUN_DIST:         48.35 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.66d {+03h 42m 38s}  +15.29d {+15d 17' 28"}
MOON_DIST:       153.73 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:13:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.738d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 19"} (J2000)
POINT_ROLL:      255.510d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54330.25 SOD {15:05:30.25} UT,   67.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.127
N_STARS:         36
X_OFFSET:        529 [pixels]
Y_OFFSET:        532 [pixels]
X_MAX:           1488 [pixels]
Y_MAX:           1491 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00657286000msufc0067.fits
SUN_POSTN:       187.46d {+12h 29m 52s}   -3.22d {-03d 13' 22"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.68d {+03h 42m 44s}  +15.30d {+15d 17' 44"}
MOON_DIST:       153.73 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:11:48 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.738d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 19"} (J2000)
ROLL:            255.510d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54330.25 SOD {15:05:30.25} UT,   67.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     465404745
X_OFFSET:        848 [pixels]
Y_OFFSET:        851 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1008
Y_GRB_POS:       1011
BINNING_INDEX:   1
IM_URL:          sw00657286000msuni0083.fits
SUN_POSTN:       187.46d {+12h 29m 51s}   -3.22d {-03d 13' 20"}
SUN_DIST:         48.35 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.67d {+03h 42m 41s}  +15.29d {+15d 17' 35"}
MOON_DIST:       153.73 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:13:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.738d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 19"} (J2000)
ROLL:            255.510d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54330.25 SOD {15:05:30.25} UT,   67.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     465404745
X_OFFSET:        848 [pixels]
Y_OFFSET:        851 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1008
Y_GRB_POS:       1011
BINNING_INDEX:   1
IM_URL:          sw00657286000msuni0083.fits
SUN_POSTN:       187.46d {+12h 29m 52s}   -3.22d {-03d 13' 21"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.68d {+03h 42m 43s}  +15.30d {+15d 17' 43"}
MOON_DIST:       153.73 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:17:25 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.973d {+10d 58' 21"} (J2000)
POINT_ROLL:      255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54542.07 SOD {15:09:02.07} UT,   279.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.934
N_STARS:         66
X_OFFSET:        289 [pixels]
Y_OFFSET:        292 [pixels]
X_MAX:           1728 [pixels]
Y_MAX:           1731 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00657286000msufc0279.fits
SUN_POSTN:       187.47d {+12h 29m 52s}   -3.22d {-03d 13' 26"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.73d {+03h 42m 54s}  +15.30d {+15d 18' 10"}
MOON_DIST:       153.72 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:18:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.973d {+10d 58' 21"} (J2000)
ROLL:            255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54542.07 SOD {15:09:02.07} UT,   279.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     465404957
X_OFFSET:        848 [pixels]
Y_OFFSET:        851 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1008
Y_GRB_POS:       1011
BINNING_INDEX:   1
IM_URL:          sw00657286000msuni0295.fits
SUN_POSTN:       187.47d {+12h 29m 52s}   -3.22d {-03d 13' 27"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.74d {+03h 42m 57s}  +15.30d {+15d 18' 17"}
MOON_DIST:       153.71 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:18:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.973d {+10d 58' 21"} (J2000)
ROLL:            255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54542.07 SOD {15:09:02.07} UT,   279.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     465404957
X_OFFSET:        848 [pixels]
Y_OFFSET:        851 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1008
Y_GRB_POS:       1011
BINNING_INDEX:   1
IM_URL:          sw00657286000msuni0295.fits
SUN_POSTN:       187.47d {+12h 29m 52s}   -3.22d {-03d 13' 27"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.74d {+03h 42m 58s}  +15.31d {+15d 18' 19"}
MOON_DIST:       153.71 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:17:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.973d {+10d 58' 21"} (J2000)
POINT_ROLL:      255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54542.07 SOD {15:09:02.07} UT,   279.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.934
N_STARS:         66
X_OFFSET:        289 [pixels]
Y_OFFSET:        292 [pixels]
X_MAX:           1728 [pixels]
Y_MAX:           1731 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00657286000msufc0279.fits
SUN_POSTN:       187.47d {+12h 29m 52s}   -3.22d {-03d 13' 26"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.73d {+03h 42m 55s}  +15.30d {+15d 18' 12"}
MOON_DIST:       153.72 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:16:14 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     657286,   Seg_Num: 0
GRB_RA:          233.7297d {+15h 34m 55.12s} (J2000),
                 233.9178d {+15h 35m 40.27s} (current),
                 233.1328d {+15h 32m 31.88s} (1950)
GRB_DEC:         +10.9670d {+10d 58' 01.2"} (J2000),
                 +10.9152d {+10d 54' 54.8"} (current),
                 +11.1329d {+11d 07' 58.3"} (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:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54535.00 SOD {15:08:55.00} UT,   272.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       187.47d {+12h 29m 52s}   -3.22d {-03d 13' 25"}
SUN_DIST:         48.33 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.71d {+03h 42m 51s}  +15.30d {+15d 18' 03"}
MOON_DIST:       153.72 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.18, 48.37 [deg] galactic lon,lat of the burst
ECL_COORDS:      228.24, 29.30 [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.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:18:53 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     657286,   Seg_Num: 0
GRB_RA:          233.7287d {+15h 34m 54.88s} (J2000),
                 233.9168d {+15h 35m 40.03s} (current),
                 233.1318d {+15h 32m 31.64s} (1950)
GRB_DEC:         +10.9672d {+10d 58' 01.9"} (J2000),
                 +10.9154d {+10d 54' 55.6"} (current),
                 +11.1331d {+11d 07' 59.0"} (1950)
GRB_ERROR:       0.6 [arcsec radius, statistical only]
GRB_MAG:         17.94 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54328.00 SOD {15:05:28.00} UT,   65.1 [sec] since BAT Trigger Time
SUN_POSTN:       187.47d {+12h 29m 52s}   -3.22d {-03d 13' 27"}
SUN_DIST:         48.33 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.74d {+03h 42m 58s}  +15.31d {+15d 18' 19"}
MOON_DIST:       153.72 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.18, 48.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      228.24, 29.30 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:25:13 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 21"} (J2000)
POINT_ROLL:      255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  55119.33 SOD {15:18:39.33} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.669
N_STARS:         172
X_OFFSET:        289 [pixels]
Y_OFFSET:        292 [pixels]
X_MAX:           1728 [pixels]
Y_MAX:           1731 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00657286000msufc0856.fits
SUN_POSTN:       187.47d {+12h 29m 53s}   -3.23d {-03d 13' 33"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.81d {+03h 43m 13s}  +15.32d {+15d 18' 59"}
MOON_DIST:       153.70 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 01 Oct 15 15:25:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 21"} (J2000)
POINT_ROLL:      255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  55119.33 SOD {15:18:39.33} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.669
N_STARS:         172
X_OFFSET:        289 [pixels]
Y_OFFSET:        292 [pixels]
X_MAX:           1728 [pixels]
Y_MAX:           1731 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00657286000msufc0856.fits
SUN_POSTN:       187.47d {+12h 29m 53s}   -3.23d {-03d 13' 33"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.81d {+03h 43m 14s}  +15.32d {+15d 18' 59"}
MOON_DIST:       153.70 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:27:06 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 21"} (J2000)
ROLL:            255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  55119.33 SOD {15:18:39.33} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     465405534
X_OFFSET:        848 [pixels]
Y_OFFSET:        851 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1008
Y_GRB_POS:       1011
BINNING_INDEX:   1
IM_URL:          sw00657286000msuni0872.fits
SUN_POSTN:       187.47d {+12h 29m 54s}   -3.23d {-03d 13' 35"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.83d {+03h 43m 18s}  +15.32d {+15d 19' 10"}
MOON_DIST:       153.69 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:26:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     657286,   Seg_Num: 0
POINT_RA:        233.739d {+15h 34m 57s} (J2000)
POINT_DEC:       +10.972d {+10d 58' 21"} (J2000)
ROLL:            255.508d
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  55119.33 SOD {15:18:39.33} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     465405534
X_OFFSET:        848 [pixels]
Y_OFFSET:        851 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1008
Y_GRB_POS:       1011
BINNING_INDEX:   1
IM_URL:          sw00657286000msuni0872.fits
SUN_POSTN:       187.47d {+12h 29m 54s}   -3.23d {-03d 13' 35"}
SUN_DIST:         48.34 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.82d {+03h 43m 17s}  +15.32d {+15d 19' 09"}
MOON_DIST:       153.69 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.19, 48.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      228.25, 29.31 [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:     Thu 01 Oct 15 15:23:37 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     657286,   Seg_Num: 0
GRB_RA:          233.7290d {+15h 34m 54.96s} (J2000),
                 233.9171d {+15h 35m 40.10s} (current),
                 233.1321d {+15h 32m 31.71s} (1950)
GRB_DEC:         +10.9672d {+10d 58' 01.9"} (J2000),
                 +10.9154d {+10d 54' 55.6"} (current),
                 +11.1331d {+11d 07' 59.0"} (1950)
GRB_ERROR:       2.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17296 TJD;   274 DOY;   15/10/01
IMG_START_TIME:  54535.00 SOD {15:08:55.00} UT,   272.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       187.47d {+12h 29m 53s}   -3.23d {-03d 13' 32"}
SUN_DIST:         48.33 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:       55.79d {+03h 43m 09s}  +15.31d {+15d 18' 49"}
MOON_DIST:       153.71 [deg]
MOON_ILLUM:      83 [%]
GAL_COORDS:       18.18, 48.37 [deg] galactic lon,lat of the burst
ECL_COORDS:      228.24, 29.30 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #18373
M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), S. L. Gibson (U Leicester), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 15:04:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151001A (trigger=657286). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 233.731, +10.971 which is
```
   RA(J2000) = 15h 34m 55s
   Dec(J2000) = +10d 58' 16"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a couple overlapping peaks with a duration of about 100 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~10 sec after the trigger.
The XRT began observing the field at 15:05:26.9 UT, 64.0 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 233.7289, 10.9669 which is equivalent to:
```
   RA(J2000)  = 15h 34m 54.94s
   Dec(J2000) = +10d 58' 00.8"
```
with an uncertainty of 2.0 arcseconds (radius, 90% containment). This location is 16 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 (3.53 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.3 (+1.39/-1.27) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 67 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	15:34:54.90 = 233.72874
  DEC(J2000) = +10:58:02.1  =  10.96724
```
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.8 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.94 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.04.
Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #18375
B. Mailyan (UAH), P. Veres (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 15:04:22.41 UT on 01 October 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 151001A (trigger 465404666 / 151001628) which was also detected by the Swift/BAT and XRT (M. Stamatikos et al. 2015, GCN 18373) The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 22 degrees.
The GBM light curve has a duration (T90) of about 15.1 s (50-300 keV). The time-averaged spectrum from T0-6.1 s to T0+4.1 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.54 +/- 0.21 and the cutoff energy, parameterized as Epeak, is 213.80 +/- 36.90 keV.
The event fluence (10-1000 keV) in this time interval is (1.798 +/- 0.195)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.75 s in the 10-1000 keV band is 2.2 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #18376
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 2627 s of XRT Photon Counting mode data and 5 UVOT images for GRB 151001A, 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 = 233.72875, +10.96720 which is equivalent to:
```
RA (J2000): 15h 34m 54.90s
Dec (J2000): +10d 58' 01.9"
```
with an uncertainty of 1.5 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 #18378
A. Melandri (INAF-OAB), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and M. Stamatikos report on behalf of the Swift-XRT team:
We have analysed 8.2 ks of XRT data for GRB 151001A (Stamatikos et al. GCN Circ. 18373), from 49 s to 36.0 ks after the BAT trigger. The data comprise 9 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 18376).
The late-time light curve (from T0+4.8 ks) can be modelled with a power-law decay with a decay index of alpha=1.18 (+0.23, -0.20).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.78 (+/-0.14). The best-fitting absorption column is 8.0 (+4.0, -3.6) x 10^20 cm^-2, in excess of the Galactic value of 3.5 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     8.0 (+4.0, -3.6) x 10^20 cm^-2
Galactic foreground: 3.5 x 10^20 cm^-2
Excess significance: 2.1 sigma
Photon index:	     1.78 (+/-0.14)
```
If the light curve continues to decay with a power-law decay index of 1.18, the count rate at T+24 hours will be 2.8 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x 10^-13 (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/00657286.
This circular is an official product of the Swift-XRT team.
GCN Circular #18379
T. Kruehler (MPE), J. P. U. Fynbo, D. Malesani (DARK/NBI), and P. Jakobsson (U. Iceland) report on behalf of a larger collaboration:
We observed the field of GRB 151001A (Swift trigger 657286, Stamatikos et al., GCN Circ. 18373) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC on the evening of 01-Oct-2015 between 19:55-20:24 UT (5 hr after the burst). In SDSS filters r and g we clearly detect the optical afterglow of GRB 151001A at the position given by UVOT (Stamatikos et al., GCN Circ. 18373). We derive AB magnitudes of
```
g = 22.18 +/- 0.05
r = 21.51 +/- 0.08
```
calibrated against SDSS field stars. The g-r color of the afterglow is relatively red compared to typical afterglows.
GCN Circular #18381
A. A. Breeveld (UCL-MSSL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 151001A 46 s after the BAT trigger (Stamatikos et al., GCN Circ. 18373). A fading source consistent with the enhanced XRT position (Beardmore et al. GCN Circ. 18376) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
     RA  (J2000) =3D  15:34:54.90 =3D 233.72875 (deg.)
     Dec (J2000) =3D +10:58:02.2  =3D  10.96728 (deg.)
```
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               67          217          147         17.82 =B1 0.06
white              559          578           20         19.5  =B1 0.3
v                   46         1403          110         18.78 =B1 0.29
b                  534         1502           97         19.60 =B1 0.29
u                  279          529          246         19.13 =B1 0.15
w1                 657         1453           97        >19.3
m2                 806         1428           39        >18.0
w2                1358         1552           39        >18.4
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) =3D 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #18386
V. Zach Golkhou (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos=EF=BF=BD A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=EF=BF=BDs Gonz=EF=BF=BDlez (UNAM), Carlos Rom=EF=BF =BDn-Z=EF=BF=BD=EF=BF=BDiga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), and Vicki Toy (UMD) report:
We observed the field of GRB 151001A (Stamatikos, et al., GCN 18373) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=EF=BF=BDmico Nacional on Sierra San Pedro M=EF=BF=BDrtir from 2015/10 2.10 to 2015/10 2.15 UTC (11.31 to=20 12.60 hours after the BAT trigger), obtaining a total of 1.07 hours exposure in the r, i, and z bands.
For a source within the Swift-XRT error circle (Beardmore et al., GCN 18376), in comparison with the SDSS DR9 catalog, we obtain the following detections and upper limit (3-sigma):
```
   r   =3D  22.69 +/- 0.20
   i   =3D  22.59 +/- 0.20
   z   >  20.03
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The source has faded by about 1 magnitude relative to the earlier observations by the NOT (Kruehler, et al. GCN 18379).
We thank the staff of the Observatorio Astron=EF=BF=BDmico Nacional in San Pedro M=EF=BF=BDrtir.
GCN Circular #18387
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 151001A (trigger #657286) (Stamatikos, et al., GCN Circ. 18373). The BAT ground-calculated position is RA, Dec = 233.722, 10.984 deg which is
```
  RA(J2000)  =  15h 34m 53.2s
  Dec(J2000) = +10d 59' 01.1"
```
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a single-peaked structure that starts at ~T-6 s, peaks at ~T0, end ends at~T+5 s. T90 (15-350 keV) is 8.94 +- 1.07 sec (estimated error including systematics).
The time-averaged spectrum from T-6.28 to T+4.53 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.17 +- 0.11. The fluence in the 15-150 keV band is 6.7 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.04 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/657286/BA/

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Jochen Greiner, last update: 03-Oct-2015 [Disclaimer]