Gamma-ray Burst 131018A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:49:10 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     574935,   Seg_Num: 0
GRB_RA:           98.462d {+06h 33m 51s} (J2000),
                  98.611d {+06h 34m 27s} (current),
                  97.921d {+06h 31m 41s} (1950)
GRB_DEC:         -19.882d {-19d 52' 54"} (J2000),
                 -19.893d {-19d 53' 35"} (current),
                 -19.842d {-19d 50' 31"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=3891 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        16583 TJD;   291 DOY;   13/10/18
GRB_TIME:        46068.83 SOD {12:47:48.83} UT
GRB_PHI:          60.46 [deg]
GRB_THETA:         1.91 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    16.77 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +5  +0  +0 +17  +0 
SUN_POSTN:       203.45d {+13h 33m 48s}   -9.79d {-09d 47' 15"}
SUN_DIST:        100.34 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.65d {+01h 10m 36s}   +9.15d {+09d 09' 15"}
MOON_DIST:        84.74 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.66 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      100.91,-43.00 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
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 = 185.61,-15.15 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:50:14 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     574935,   Seg_Num: 0
GRB_RA:           98.4706d {+06h 33m 52.94s} (J2000),
                  98.6199d {+06h 34m 28.76s} (current),
                  97.9297d {+06h 31m 43.12s} (1950)
GRB_DEC:         -19.8956d {-19d 53' 44.1"} (J2000),
                 -19.9070d {-19d 54' 25.2"} (current),
                 -19.8559d {-19d 51' 21.2"} (1950)
GRB_ERROR:       4.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       4.45e-09 [erg/cm2/sec]
GRB_SIGNIF:      11.74 [sigma]
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46181.48 SOD {12:49:41.48} UT,   112.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.63 237.23 261.52 243.70
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       203.45d {+13h 33m 48s}   -9.79d {-09d 47' 16"}
SUN_DIST:        100.33 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.66d {+01h 10m 38s}   +9.16d {+09d 09' 25"}
MOON_DIST:        84.74 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      229.00,-12.66 [deg] galactic lon,lat of the burst
ECL_COORDS:      100.92,-43.01 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.95 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:50:24 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     574935,   Seg_Num: 0
GRB_RA:           98.4706d {+06h 33m 52.9s} (J2000),
                  98.6199d {+06h 34m 28.7s} (current),
                  97.9297d {+06h 31m 43.1s} (1950)
GRB_DEC:         -19.8956d {-19d 53' 44.1"} (J2000),
                 -19.9070d {-19d 54' 25.2"} (current),
                 -19.8559d {-19d 51' 21.2"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       138 [cnts]
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46181.48 SOD {12:49:41.48} UT,   112.7 [sec] since BAT Trigger Time
CENTROID_X:      280.03,  raw= 280  [pixels]
CENTROID_Y:      284.55,  raw= 285  [pixels]
ROLL:            104.51 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -31.68
GRB_POS_XRT_Z:   -55.78
IMAGE_URL:       sw00574935000msxps_rw.img
SUN_POSTN:       203.45d {+13h 33m 48s}   -9.79d {-09d 47' 16"}
SUN_DIST:        100.33 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.66d {+01h 10m 38s}   +9.16d {+09d 09' 27"}
MOON_DIST:        84.74 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      229.00,-12.66 [deg] galactic lon,lat of the burst
ECL_COORDS:      100.92,-43.01 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:50:34 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     574935,   Seg_Num: 0
GRB_RA:           98.4706d {+06h 33m 52.9s} (J2000),
                  98.6199d {+06h 34m 28.7s} (current),
                  97.9297d {+06h 31m 43.1s} (1950)
GRB_DEC:         -19.8956d {-19d 53' 44.1"} (J2000),
                 -19.9070d {-19d 54' 25.2"} (current),
                 -19.8559d {-19d 51' 21.2"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       138 [cnts]
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46181.48 SOD {12:49:41.48} UT,   112.7 [sec] since BAT Trigger Time
CENTROID_X:      280.03,  raw= 280  [pixels]
CENTROID_Y:      284.55,  raw= 285  [pixels]
ROLL:            104.51 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -31.68
GRB_POS_XRT_Z:   -55.78
IMAGE_URL:       sw00574935000msxps_rw.img
SUN_POSTN:       203.45d {+13h 33m 48s}   -9.79d {-09d 47' 16"}
SUN_DIST:        100.33 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.66d {+01h 10m 39s}   +9.16d {+09d 09' 29"}
MOON_DIST:        84.74 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      229.00,-12.66 [deg] galactic lon,lat of the burst
ECL_COORDS:      100.92,-43.01 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:51:48 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     574935,   Seg_Num: 0
GRB_RA:           98.462d {+06h 33m 51s} (J2000),
                  98.611d {+06h 34m 27s} (current),
                  97.921d {+06h 31m 41s} (1950)
GRB_DEC:         -19.882d {-19d 52' 54"} (J2000),
                 -19.893d {-19d 53' 35"} (current),
                 -19.842d {-19d 50' 31"} (1950)
GRB_DATE:        16583 TJD;   291 DOY;   13/10/18
GRB_TIME:        46068.83 SOD {12:47:48.83} UT
TRIGGER_INDEX:   20000
GRB_PHI:          60.46 [deg]
GRB_THETA:         1.91 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    16.77 [sigma]
LC_URL:          sw00574935000msb.lc
SUN_POSTN:       203.45d {+13h 33m 49s}   -9.79d {-09d 47' 17"}
SUN_DIST:        100.34 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.67d {+01h 10m 41s}   +9.16d {+09d 09' 41"}
MOON_DIST:        84.72 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.66 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      100.91,-43.00 [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 an image 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 = 185.61,-15.15 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:52:58 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.456d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 53' 00"} (J2000)
POINT_ROLL:      104.511d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46189.36 SOD {12:49:49.36} UT,   120.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.334
N_STARS:         160
X_OFFSET:        496 [pixels]
Y_OFFSET:        536 [pixels]
X_MAX:           1455 [pixels]
Y_MAX:           1495 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00574935000msufc0120.fits
SUN_POSTN:       203.45d {+13h 33m 49s}   -9.79d {-09d 47' 18"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.68d {+01h 10m 44s}   +9.16d {+09d 09' 52"}
MOON_DIST:        84.71 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:53:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.456d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 53' 00"} (J2000)
POINT_ROLL:      104.511d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46189.36 SOD {12:49:49.36} UT,   120.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.334
N_STARS:         160
X_OFFSET:        496 [pixels]
Y_OFFSET:        536 [pixels]
X_MAX:           1455 [pixels]
Y_MAX:           1495 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00574935000msufc0120.fits
SUN_POSTN:       203.45d {+13h 33m 49s}   -9.79d {-09d 47' 19"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.69d {+01h 10m 44s}   +9.17d {+09d 09' 55"}
MOON_DIST:        84.70 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:54:16 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.456d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 53' 00"} (J2000)
ROLL:            104.511d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46189.36 SOD {12:49:49.36} UT,   120.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     403793400
X_OFFSET:        923 [pixels]
Y_OFFSET:        882 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1083
Y_GRB_POS:       1042
BINNING_INDEX:   1
IM_URL:          sw00574935000msuni0132.fits
SUN_POSTN:       203.45d {+13h 33m 49s}   -9.79d {-09d 47' 20"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.69d {+01h 10m 47s}   +9.17d {+09d 10' 05"}
MOON_DIST:        84.70 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:54:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.456d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 53' 00"} (J2000)
ROLL:            104.511d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46189.36 SOD {12:49:49.36} UT,   120.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     403793400
X_OFFSET:        923 [pixels]
Y_OFFSET:        882 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1083
Y_GRB_POS:       1042
BINNING_INDEX:   1
IM_URL:          sw00574935000msuni0132.fits
SUN_POSTN:       203.45d {+13h 33m 49s}   -9.79d {-09d 47' 20"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.70d {+01h 10m 47s}   +9.17d {+09d 10' 08"}
MOON_DIST:        84.70 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:57:14 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
POINT_ROLL:      104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46347.44 SOD {12:52:27.44} UT,   278.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.690
N_STARS:         168
X_OFFSET:        603 [pixels]
Y_OFFSET:        562 [pixels]
X_MAX:           1562 [pixels]
Y_MAX:           1521 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00574935000msufc0278.fits
SUN_POSTN:       203.46d {+13h 33m 49s}   -9.79d {-09d 47' 22"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.72d {+01h 10m 53s}   +9.18d {+09d 10' 34"}
MOON_DIST:        84.68 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:57:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
POINT_ROLL:      104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46347.44 SOD {12:52:27.44} UT,   278.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.690
N_STARS:         168
X_OFFSET:        603 [pixels]
Y_OFFSET:        562 [pixels]
X_MAX:           1562 [pixels]
Y_MAX:           1521 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00574935000msufc0278.fits
SUN_POSTN:       203.46d {+13h 33m 49s}   -9.79d {-09d 47' 22"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.72d {+01h 10m 53s}   +9.18d {+09d 10' 35"}
MOON_DIST:        84.68 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:58:12 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     574935,   Seg_Num: 0
GRB_RA:           98.4709d {+06h 33m 53.01s} (J2000),
                  98.6202d {+06h 34m 28.84s} (current),
                  97.9300d {+06h 31m 43.20s} (1950)
GRB_DEC:         -19.8977d {-19d 53' 51.7"} (J2000),
                 -19.9091d {-19d 54' 32.8"} (current),
                 -19.8580d {-19d 51' 28.7"} (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:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46348.00 SOD {12:52:28.00} UT,   279.2 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       203.46d {+13h 33m 50s}   -9.79d {-09d 47' 23"}
SUN_DIST:        100.33 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.73d {+01h 10m 55s}   +9.18d {+09d 10' 43"}
MOON_DIST:        84.69 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      229.00,-12.66 [deg] galactic lon,lat of the burst
ECL_COORDS:      100.92,-43.02 [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 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:58:43 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
ROLL:            104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46347.44 SOD {12:52:27.44} UT,   278.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     403793558
X_OFFSET:        923 [pixels]
Y_OFFSET:        882 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1083
Y_GRB_POS:       1042
BINNING_INDEX:   1
IM_URL:          sw00574935000msuni0290.fits
SUN_POSTN:       203.46d {+13h 33m 50s}   -9.79d {-09d 47' 24"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.73d {+01h 10m 56s}   +9.18d {+09d 10' 49"}
MOON_DIST:        84.67 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 12:58:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
ROLL:            104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46347.44 SOD {12:52:27.44} UT,   278.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     403793558
X_OFFSET:        923 [pixels]
Y_OFFSET:        882 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1083
Y_GRB_POS:       1042
BINNING_INDEX:   1
IM_URL:          sw00574935000msuni0290.fits
SUN_POSTN:       203.46d {+13h 33m 50s}   -9.79d {-09d 47' 24"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.74d {+01h 10m 56s}   +9.18d {+09d 10' 50"}
MOON_DIST:        84.67 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #15349
A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), P. D\'Avanzo (INAF-OAB), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), S. T. Holland (STScI), J. A. Kennea (PSU), A. Y. Lien (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC), A. Maselli (INAF-IASFPA), C. Pagani (U Leicester), K. L. Page (U Leicester), P. Romano (INAF-IASFPA), M. H. Siegel (PSU) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 12:47:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 131018A (trigger=574935). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 98.462, -19.882 which is
```
   RA(J2000) = 06h 33m 51s
   Dec(J2000) = -19d 52' 54"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a broad single peak structure with a duration of about 100 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~56 sec after the trigger.
The XRT began observing the field at 12:49:41.4 UT, 112.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 98.4716, -19.8961 which is equivalent to:
```
   RA(J2000)  = 06h 33m 53.19s
   Dec(J2000) = -19d 53' 45.9"
```
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This location is 60 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 2.03 x 10^21 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 4.45e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 120 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 typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.26.
Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it). 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:     Fri 18 Oct 13 13:04:59 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
POINT_ROLL:      104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46924.93 SOD {13:02:04.93} UT,   856.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.480
N_STARS:         190
X_OFFSET:        363 [pixels]
Y_OFFSET:        322 [pixels]
X_MAX:           1802 [pixels]
Y_MAX:           1761 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00574935000msufc0856.fits
SUN_POSTN:       203.46d {+13h 33m 51s}   -9.79d {-09d 47' 29"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.79d {+01h 11m 09s}   +9.20d {+09d 11' 50"}
MOON_DIST:        84.62 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 13:05:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
POINT_ROLL:      104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46924.93 SOD {13:02:04.93} UT,   856.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.480
N_STARS:         190
X_OFFSET:        363 [pixels]
Y_OFFSET:        322 [pixels]
X_MAX:           1802 [pixels]
Y_MAX:           1761 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00574935000msufc0856.fits
SUN_POSTN:       203.46d {+13h 33m 51s}   -9.79d {-09d 47' 30"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.79d {+01h 11m 11s}   +9.20d {+09d 11' 55"}
MOON_DIST:        84.62 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 13:06:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
ROLL:            104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46924.93 SOD {13:02:04.93} UT,   856.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     403794136
X_OFFSET:        922 [pixels]
Y_OFFSET:        881 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       1041
BINNING_INDEX:   1
IM_URL:          sw00574935000msuni0868.fits
SUN_POSTN:       203.46d {+13h 33m 51s}   -9.79d {-09d 47' 31"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.80d {+01h 11m 13s}   +9.20d {+09d 12' 05"}
MOON_DIST:        84.61 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Oct 13 13:06:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     574935,   Seg_Num: 0
POINT_RA:         98.458d {+06h 33m 50s} (J2000)
POINT_DEC:       -19.883d {-19d 52' 57"} (J2000)
ROLL:            104.508d
IMG_START_DATE:  16583 TJD;   291 DOY;   13/10/18
IMG_START_TIME:  46924.93 SOD {13:02:04.93} UT,   856.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     403794136
X_OFFSET:        922 [pixels]
Y_OFFSET:        881 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1082
Y_GRB_POS:       1041
BINNING_INDEX:   1
IM_URL:          sw00574935000msuni0868.fits
SUN_POSTN:       203.46d {+13h 33m 51s}   -9.79d {-09d 47' 31"}
SUN_DIST:        100.35 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:       17.81d {+01h 11m 13s}   +9.20d {+09d 12' 07"}
MOON_DIST:        84.61 [deg]
MOON_ILLUM:      100 [%]
GAL_COORDS:      228.98,-12.67 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      100.90,-43.00 [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 #15350
Arne Henden (AAVSO), as part of a larger collaboration, reports:
We observed the field of GRB131018 using the Mt. John University Observatory Optical Craftsman 61cm telescope (part of AAVSOnet), with observations starting at 12:55:24 UT (7.6 minutes after the Swift trigger) under poor seeing conditions and bright moonlight. We do not see any optical afterglow at the XRT position to a limiting magnitude of R=17 (using APASS calibrations).
GCN Circular #15352
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1872 s of XRT Photon Counting mode data and 1 UVOT images for GRB 131018A, 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 = 98.47133, -19.89620 which is equivalent to:
```
RA (J2000): 06h 33m 53.12s
Dec (J2000): -19d 53' 46.3"
```
with an uncertainty of 1.9 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 #15353
S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a larger collaboration:
We have observed the location of the Swift GRB131018A (Melandri et al., GCN 15349) with the robotic Palomar 60 inch telescope. Two 60 s frames were obtained before the telescope closed due to the imminent sunrise. We find no new sources within the enhanced XRT error circle (Goad et al., GCN 15352). Using nearby point sources from SDSS for photometric calibration, we the following upper limits:
```
r' > 20.1 mag at 12:56 UT (dt = 8.6 min)
i' > 19.5 mag at 12:58 (dt = 10.0 min)
```
GCN Circular #15354
T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (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 131018A (trigger #574935) (Melandri, et al., GCN Circ. 15349). The BAT ground-calculated position is RA, Dec = 98.473, -19.897 deg which is
```
  RA(J2000)  =  06h 33m 53.4s
  Dec(J2000) = -19d 53' 48.5"
```
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a single long peak starts at ~T+21 sec and ends at ~T+118 sec. T90 (15-350 keV) is 73.22 +- 18.97 sec (estimated error including systematics).
The time-averaged spectrum from T+21.10 to T+117.74 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.24 +- 0.14. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+59.41 sec in the 15-150 keV band is 0.5 +- 0.1 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/574935/BA/
GCN Circular #15355
WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to GRB 131018A (Melandri et al., GCN 15349) starting at 12:50:47 UT, 179 s after the burst. Observations were performed with an automatic sequence in the V, I, and clear(roughly R) filters, and the exposure time was 20 s per image. Comparing to the SDSS image, we do not detect new sources in our single images or in coadds of 5 images within the enhanced XRT error circle (Goad et al., GCN 15352). There is a faint stellar object (r = 22.2 mag) in the SDSS image 1.8" from the enhanced XRT position, but it is beyond our limiting magnitudes of R ~ 18.7 for single images and R ~ 19.6 for 5 coadded images.
GCN Circular #15356
V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), J.A. Kennea (PSU), V. Mangano (PSU), M.C. Stroh (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester) and A. Melandri report on behalf of the Swift-XRT team:
We have analysed 11 ks of XRT data for GRB 131018A (Melandri et al. GCN Circ. 15349), from 119 s to 25.2 ks after the BAT trigger. The data comprise 171 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 15352).
The light curve can be modelled with an initial power-law decay with an index of alpha=4.24 (+0.17, -0.15), followed by a break at T+549 s to an alpha of 0.30 (+/-0.06).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.06 (+0.13, -0.12). The best-fitting absorption column is 4.3 (+/-0.3) x 10^21 cm^-2, in excess of the Galactic value of 2.0 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.16 (+0.18, -0.17) and a best-fitting absorption column of 3.1 (+/-0.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (6.7 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     3.1 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 2.0 x 10^21 cm^-2
Excess significance: 2.9 sigma
Photon index:	     2.16 (+0.18, -0.17)
```
If the light curve continues to decay with a power-law decay index of 0.30, the count rate at T+24 hours will be 0.040 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x 10^-12 (2.7 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/00574935.
This circular is an official product of the Swift-XRT team.
GCN Circular #15358
M. De Pasquale (UCL-MSSL) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 131018A 99 s after the BAT trigger (Melandri et al., GCN Circ. 15349). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 15352) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           120          270          147         >21.3
u_FC               279          528          246         >20.5
white              120        13702         1588         >22.4
v                   99         7600          581         >20.3
b                  534        19468         2174         >22.0
u                  279        18703         2368         >21.9
w1                 657        17790         1382         >21.3
m2                 632         7805          568         >20.5
w2                 584         7395          568         >20.8
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.26 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #15359
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), Willia= m H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB)= , J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos=E9 A. de Diego (UNAM), Leonid Georgiev (UNAM), J= es=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC),= and Harvey Moseley (GSFC) report:
We observed the field of GRB 131018A (Melandri, et al., GCN 15349) with t= he Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional = on Sierra San Pedro M=E1rtir from 2013/10 19.34 to 2013/10 19.53 UTC (19.36 = to 23.83 hours after the BAT trigger), obtaining a total of 2.58 hours exposure in the r and i bands and 1.09 hours exposure in the Z, Y, J, and= H bands.
We detect no new sources within the enhanced Swift-XRT error circle (Goad= , et al., GCN 15352). In comparison with the SDSS DR9 and 2MASS, we obtain the following upper limits (3-sigma):
```
  r > 23.30
  i > 23.18
  Z > 22.43
  Y > 22.05
  J > 21.70
  H > 21.27
```
The SDSS source present in the XRT error circle (see also, Zheng, et al., GCN 15355) is well-detected, apparently non-extended, and is measured to have the following magnitudes:
```
  r     22.06 +/- 0.11
  i     20.73 +/- 0.05
  Z     20.10 +/- 0.05
  Y     19.63 +/- 0.05
  J     19.64 +/- 0.06
  H     19.18 +/- 0.06
```
The above magnitude are in the AB system and are not corrected for Galact= ic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Report 450.1
GCN_Report 450.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_450_1.pdf by A. Melandri at INAF-OAB titled: "Swift Observations of GRB 131018A"

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Jochen Greiner, last update: 26-Apr-2014 [Disclaimer]