Gamma-ray Burst 151118A

(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:     Wed 18 Nov 15 03:06:51 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     664078,   Seg_Num: 0
GRB_RA:           57.158d {+03h 48m 38s} (J2000),
                  57.528d {+03h 50m 07s} (current),
                  56.001d {+03h 44m 00s} (1950)
GRB_DEC:         +65.869d {+65d 52' 07"} (J2000),
                 +65.916d {+65d 54' 59"} (current),
                 +65.715d {+65d 42' 55"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1845 [cnts]    Image_Peak=126 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   124     E_range: 25-100 keV
BKG_INTEN:       21669 [cnts]
BKG_TIME:        11176.57 SOD {03:06:16.57} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17344 TJD;   322 DOY;   15/11/18
GRB_TIME:        11190.01 SOD {03:06:30.01} UT
GRB_PHI:          12.72 [deg]
GRB_THETA:        15.89 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.91 [sigma]
IMAGE_SIGNIF:    7.82 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2  -2  +0  +1 +68  +0 
SUN_POSTN:       233.11d {+15h 32m 25s}  -19.12d {-19d 07' 15"}
SUN_DIST:        133.11 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.50d {+20h 50m 01s}  -13.80d {-13d 47' 44"}
MOON_DIST:       108.69 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.96 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       71.90, 44.48 [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 = 247.79,11.87 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 18 Nov 15 03:07:51 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.146d {+03h 48m 35s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 00"} (J2000)
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11256.25 SOD {03:07:36.25} UT,   66.2 [sec] since BAT Trigger Time
COUNTS:          4    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 18 Nov 15 03:10:16 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     664078,   Seg_Num: 0
GRB_RA:           57.158d {+03h 48m 38s} (J2000),
                  57.528d {+03h 50m 07s} (current),
                  56.001d {+03h 44m 00s} (1950)
GRB_DEC:         +65.869d {+65d 52' 07"} (J2000),
                 +65.916d {+65d 54' 59"} (current),
                 +65.715d {+65d 42' 55"} (1950)
GRB_DATE:        17344 TJD;   322 DOY;   15/11/18
GRB_TIME:        11190.01 SOD {03:06:30.01} UT
TRIGGER_INDEX:   124
GRB_PHI:          12.72 [deg]
GRB_THETA:        15.89 [deg]
DELTA_TIME:      -63.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.91 [sigma]
IMAGE_SIGNIF:    7.82 [sigma]
LC_URL:          sw00664078000msb.lc
SUN_POSTN:       233.11d {+15h 32m 26s}  -19.12d {-19d 07' 17"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.54d {+20h 50m 09s}  -13.79d {-13d 47' 20"}
MOON_DIST:       108.67 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.96 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       71.90, 44.48 [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 = 247.79,11.87 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 18 Nov 15 03:10:52 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.146d {+03h 48m 35s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 00"} (J2000)
POINT_ROLL:      5.255d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11259.74 SOD {03:07:39.74} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.197
N_STARS:         151
X_OFFSET:        512 [pixels]
Y_OFFSET:        594 [pixels]
X_MAX:           1471 [pixels]
Y_MAX:           1553 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00664078000msufc0069.fits
SUN_POSTN:       233.11d {+15h 32m 26s}  -19.12d {-19d 07' 17"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.54d {+20h 50m 10s}  -13.79d {-13d 47' 16"}
MOON_DIST:       108.66 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 18 Nov 15 03:12:16 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.146d {+03h 48m 35s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 00"} (J2000)
ROLL:            5.255d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11259.74 SOD {03:07:39.74} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     469508875
X_OFFSET:        831 [pixels]
Y_OFFSET:        913 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       991
Y_GRB_POS:       1073
BINNING_INDEX:   1
IM_URL:          sw00664078000msuni0085.fits
SUN_POSTN:       233.11d {+15h 32m 26s}  -19.12d {-19d 07' 18"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.56d {+20h 50m 13s}  -13.79d {-13d 47' 06"}
MOON_DIST:       108.65 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [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:     Wed 18 Nov 15 03:12:36 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     664078,   Seg_Num: 0
GRB_RA:           57.1715d {+03h 48m 41.16s} (J2000),
                  57.5416d {+03h 50m 09.97s} (current),
                  56.0133d {+03h 44m 03.18s} (1950)
GRB_DEC:         +65.9011d {+65d 54' 03.9"} (J2000),
                 +65.9488d {+65d 56' 55.6"} (current),
                 +65.7478d {+65d 44' 52.0"} (1950)
GRB_ERROR:       3.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11284.00 SOD {03:08:04.00} UT,   94.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       233.11d {+15h 32m 26s}  -19.12d {-19d 07' 18"}
SUN_DIST:        133.08 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.56d {+20h 50m 14s}  -13.78d {-13d 47' 03"}
MOON_DIST:       108.66 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.72,  8.99 [deg] galactic lon,lat of the burst
ECL_COORDS:       71.92, 44.51 [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:     Wed 18 Nov 15 03:12:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.146d {+03h 48m 35s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 00"} (J2000)
ROLL:            5.255d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11259.74 SOD {03:07:39.74} UT,   69.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     469508875
X_OFFSET:        831 [pixels]
Y_OFFSET:        913 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       991
Y_GRB_POS:       1073
BINNING_INDEX:   1
IM_URL:          sw00664078000msuni0085.fits
SUN_POSTN:       233.11d {+15h 32m 26s}  -19.12d {-19d 07' 18"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.56d {+20h 50m 14s}  -13.78d {-13d 47' 04"}
MOON_DIST:       108.65 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [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:     Wed 18 Nov 15 03:18:59 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.141d {+03h 48m 34s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 03"} (J2000)
POINT_ROLL:      5.249d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11471.81 SOD {03:11:11.81} UT,   281.8 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.586
N_STARS:         73
X_OFFSET:        272 [pixels]
Y_OFFSET:        354 [pixels]
X_MAX:           1711 [pixels]
Y_MAX:           1793 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00664078000msufc0281.fits
SUN_POSTN:       233.11d {+15h 32m 28s}  -19.12d {-19d 07' 22"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.62d {+20h 50m 29s}  -13.77d {-13d 46' 18"}
MOON_DIST:       108.61 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 18 Nov 15 03:19:22 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     664078,   Seg_Num: 0
GRB_RA:           57.1719d {+03h 48m 41.25s} (J2000),
                  57.5420d {+03h 50m 10.06s} (current),
                  56.0137d {+03h 44m 03.28s} (1950)
GRB_DEC:         +65.9012d {+65d 54' 04.3"} (J2000),
                 +65.9489d {+65d 56' 55.9"} (current),
                 +65.7479d {+65d 44' 52.4"} (1950)
GRB_ERROR:       2.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11284.00 SOD {03:08:04.00} UT,   94.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       233.12d {+15h 32m 28s}  -19.12d {-19d 07' 22"}
SUN_DIST:        133.08 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.62d {+20h 50m 29s}  -13.77d {-13d 46' 16"}
MOON_DIST:       108.62 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.72,  8.99 [deg] galactic lon,lat of the burst
ECL_COORDS:       71.92, 44.51 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 18 Nov 15 03:19:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.141d {+03h 48m 34s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 03"} (J2000)
POINT_ROLL:      5.249d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11471.81 SOD {03:11:11.81} UT,   281.8 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.586
N_STARS:         73
X_OFFSET:        272 [pixels]
Y_OFFSET:        354 [pixels]
X_MAX:           1711 [pixels]
Y_MAX:           1793 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00664078000msufc0281.fits
SUN_POSTN:       233.12d {+15h 32m 28s}  -19.12d {-19d 07' 22"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.62d {+20h 50m 29s}  -13.77d {-13d 46' 16"}
MOON_DIST:       108.61 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [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:     Wed 18 Nov 15 03:20:30 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.141d {+03h 48m 34s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 03"} (J2000)
ROLL:            5.249d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11471.81 SOD {03:11:11.81} UT,   281.8 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     469509087
X_OFFSET:        831 [pixels]
Y_OFFSET:        913 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       991
Y_GRB_POS:       1073
BINNING_INDEX:   1
IM_URL:          sw00664078000msuni0297.fits
SUN_POSTN:       233.12d {+15h 32m 28s}  -19.12d {-19d 07' 23"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.63d {+20h 50m 32s}  -13.77d {-13d 46' 08"}
MOON_DIST:       108.61 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [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:     Wed 18 Nov 15 03:20:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     664078,   Seg_Num: 0
POINT_RA:         57.141d {+03h 48m 34s} (J2000)
POINT_DEC:       +65.867d {+65d 52' 03"} (J2000)
ROLL:            5.249d
IMG_START_DATE:  17344 TJD;   322 DOY;   15/11/18
IMG_START_TIME:  11471.81 SOD {03:11:11.81} UT,   281.8 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     469509087
X_OFFSET:        831 [pixels]
Y_OFFSET:        913 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       991
Y_GRB_POS:       1073
BINNING_INDEX:   1
IM_URL:          sw00664078000msuni0297.fits
SUN_POSTN:       233.12d {+15h 32m 28s}  -19.12d {-19d 07' 23"}
SUN_DIST:        133.12 [deg]   Sun_angle= 11.7 [hr] (West of Sun)
MOON_POSTN:      312.64d {+20h 50m 33s}  -13.77d {-13d 46' 05"}
MOON_DIST:       108.60 [deg]
MOON_ILLUM:      38 [%]
GAL_COORDS:      139.73,  8.95 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       71.89, 44.48 [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 #18611
A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 03:06:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151118A (trigger=664078). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 57.158, +65.869, which is
```
   RA(J2000)  =  03h 48m 38s
   Dec(J2000) = +65d 52' 07"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a few peaks with a duration of about 25 sec. The peak count rate was ~2600 counts/sec (15-350 keV), at ~6 sec after the trigger.
The XRT began observing the field at 03:07:36.2 UT, 66.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 57.1719, 65.9012 which is equivalent to:
```
   RA(J2000)  = 03h 48m 41.25s
   Dec(J2000) = +65d 54' 04.4"
```
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This location is 117 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.54 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.9 (+4.29/-3.55) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 250 seconds with the U filter starting 281 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 none of the XRT error circle. 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 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 1.10.
Burst Advocate for this burst is A. Amaral-Rogers (aar14 AT le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #18612
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), A. Sota (IAA-CSIC), and C. Thoene (IAA-CSIC) report:
We observed the field of GRB 151118A (Amaral-Rogers et al. GCN 18611) with the 1.5 m OSN telescope in Granada (Spain), starting at 03:17:55 UT (11.42 min after the GRB onset). Observations consisted of 7x300 s exposures in I-band. No new source is detected within the XRT error box. The 3-sigma limiting magnitudes of the individual exposures, and the combined frames are I(Vega) = 21.5 mag, and I(Vega) = 22.5 mag, respectively. The mean time of the combined exposure is 03:37:49 (31.32 min after the burst). Photometry was obtained by comparison with stars from the USNO-B1.0 catalogue.
GCN Circular #18613
V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D. Vlasenko, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB151118.13 30 sec after notice time and 44 sec after trigger time at 2015-11-18 03:07:17 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=03 48 37 dec=+65 52 06 r=0.05). The 5-sigma upper limit has been about 16.5 mag unfiltered.
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB151118A 24 sec after notice time and 42 sec after trigger time at 2015-11-18 03:07:12 UT in two polarizations. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (Amaral-Rogers et al GCN 18611). Our early upper limits on single and coadd images given in a table below:
Table 1. 5 sigma limit.
```
T-Ts  T-Tm  Expt.    P|     P-    coadd.
                     lim     lim 
----------------------------------------
   42    47    10    16.7   16.8     1
   42    90    50    17.9   18.0     3
   42   508   790    19.9   20.0    12
   86    96    20    17.3   17.4     1
  117   127    20    17.3   17.4     1
  147   218   120    18.7   18.8     3
  299   420   220    19.2   19.3     3
  551   762   400    19.6   19.7     3
---------------------------------------

 T   - is a trigger time [s].
Ts   - image start time [s].
Tm   - image middle time [s].
Expt - exposure time [s].
P|   - image upper limit in polarizer orientated 90 deg. to RA axis [mag].
P-   - image upper limit in polarizer orientated  0 deg. to RA axis [mag].
```
We do not see OT brighter 20 mag. There is marginal object (m~20) with 6" W (RA) and 3"S (dec) offset from XRT error box center (Ra = 03h 48m 40.40s Dec= 65d 54m 01.3s Mag ~ 20.3 +- 0.7 ).
The message may be cited.
GCN Circular #18614
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 4427 s of XRT Photon Counting mode data and 6 UVOT images for GRB 151118A, 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 = 57.17172, +65.90168 which is equivalent to:
```
RA (J2000): 03h 48m 41.21s
Dec (J2000): +65d 54' 06.1"
```
with an uncertainty of 1.6 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 #18615
M. H. Siegel (PSU) and Amaral-Rogers (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 151118A 70 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 18611). No optical afterglow consistent with the XRT position (Amaral-Rogers et al. GCN Circ. 18611) 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)           70          220          148         >20.6
u (fc)              282          532          246         >20.0
white               70          754          186         >20.8
v                  612          631           19         >18.3
b                  537          730           39         >19.3
u                  282          705          265         >19.9
w1                 661          680           19         >18.2
w2                 587          607           19         >17.9
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.10 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #18617
C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. D'ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU) and A. Amaral-Rogers report on behalf of the Swift-XRT team:
We have analysed 7.4 ks of XRT data for GRB 151118A (Amaral-Rogers et al. GCN Circ. 18611), from 52 s to 22.7 ks after the BAT trigger. The data comprise 22 s in Windowed Timing (WT) mode (the first 7 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 18614).
The late-time light curve (from T0+4.9 ks) can be modelled with a power-law decay with a decay index of alpha=1.07 (+/-0.26).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.93 (+0.23, -0.22). The best-fitting absorption column is 1.07 (+0.25, -0.21) x 10^22 cm^-2, in excess of the Galactic value of 4.5 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.1 x 10^-11 (9.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.07 (+0.25, -0.21) x 10^22 cm^-2
Galactic foreground: 4.5 x 10^21 cm^-2
Excess significance: 4.7 sigma
Photon index:	     1.93 (+0.23, -0.22)
```
If the light curve continues to decay with a power-law decay index of 1.07, the count rate at T+24 hours will be 4.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x 10^-13 (4.2 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/00664078.
This circular is an official product of the Swift-XRT team.
GCN Circular #18618
L. Elenin (KIAM), A. Volnova (IKI), E. Mazaeva (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 151118A (Amaral-Rogers et al., GCN 18611) with 0.4-m telescope of ISON-NM observatory in robotic mode starting on Nov., 18 (UT) 03:08:32 i.e. 122 seconds after burst trigger. We obtained 6 unfiltered images of 30 s exposure under unfavorable weather conditions. We do not detect any source within enhanced XRT error circle (Evans et al., GCN 18614):
```
Date       UT start   t-T0     Filter  Exp.   UL(3 sigma)
                       (mid, days)      (s)


2015-11-28 03:08:32   0.00158  None    1*30   17.4
2015-11-28 03:08:32   0.00265  None    5*30   18.0
```
The photometry is based on nearby USNO-B1.0 stars:
```
USNO-B1.0 id R2
1559-0079254 15.66
1558-0078601 16.03
1558-0078636 14.62
```
GCN Circular #18619
L. K. Hardy (Sheffield), V. S. Dhillon (Sheffield, IAC), S. P. Littlefair (Sheffield), T. Butterley (Durham) and R. W. Wilson (Durham) report:
Our automated robotic telescope 'pt5m' (Hardy et al. 2015, MNRAS 454, 4316) on La Palma observed the field of GRB 151118A (Amaral-Rogers et al., GCN 18611) starting at 03:16:27 UT on Nov 18, 10 min after the GRB detection.
Observations comprised of 46 x 60-second exposures in the R-band. We detect no new source within the XRT error box (Evans et al., GCN 18614). The 3-sigma limiting magnitude of a combined image is R = 22.1 mag. The mean time of the combined exposure is 03:42 UT (36 mins after the burst). We obtained photometry using the nearest comparison star, USNOB1.0:1559-0079286, R=15.6.
GCN Circular #18622
C. B. Markwardt (GSFC), A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+941 sec from the recent telemetry downlink, we report further analysis of BAT GRB 151118A (trigger #664078) (Amaral-Rogers, et al., GCN Circ. 18611). The BAT ground-calculated position is RA, Dec = 57.169, 65.889 deg which is
```
  RA(J2000)  =  03h 48m 40.6s
  Dec(J2000) = +65d 53' 22.0"
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 98%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~ T0 and ends at ~T+30 s. The structure contains roughly two main pulses that peak at ~ T0 and ~T+7 s, respectively. T90 (15-350 keV) is 23.4 +- 10.5 sec (estimated error including systematics).
The time-averaged spectrum from T+0.0 to T+30.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.80 +- 0.20. The fluence in the 15-150 keV band is 4.5 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+6.41 sec in the 15-150 keV band is 1.2 +- 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/664078/BA/
GCN Circular #18627
E. Mazaeva (IKI), R. Inasaridze (AAO), V. Ayvazian (AAO), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 151118A (Amaral-Rogers et al., GCN 18611) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Nov. 18 (UT) 18:08:09. We do not detect any source within enhanced XRT error circle (Evans et al., GCN 18614):
```
Date       UT start    t-T0     Filter  Exp.     UL(3 sigam)
                        (mid, days)      (s)

2015-11-18 18:08:09    0.65922  None    35*120   22.1
```
The photometry is based on nearby USNO-B1.0 stars
```
USNO-B.1_id     R2
1559-0079254	15.66
1559-0079234	16.18
1559-0079286	15.60
1559-0079243	16.15
1558-0078596	14.88
```
GCN Circular #18630
Y.Yano, T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 151118A (A. Amaral=E2=80=93= Rogers et al., GCN Circular #18611) with the=20 optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME = 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2015-11-18 19:14:09 UT (~16.1 h after the burs= t). We did not find any new point source within XRT circle in all three bands.
We obtained following limits for the magnitudes.
```
T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
-------------------------------------------------------------
58059  19:44:17  2520  > 20.3  > 19.6  > 18.4
-------------------------------------------------------------
T0+ : Elapsed time after the burst=20
T-EXP: Total Exposure time=20
We used GSC2.3 catalog for flux calibration.
```
GCN Circular #18642
Y. Kitaoka, T. Sakamoto, A. Yoshida (AGU)
We observed the field of GRB 151118A detected by Swift (trigger #664078; Amaral-Rogers et al., GCN Circ. 18611) with the iTelescope.Net (http://www.itelescope.net) T7 (17" Plane Wave) telescope located at the AstroCamp Observatory (Nerpio, Spain). 20 images of 60 sec exposures were taken in the R filter starting from November 18 03:45:22 (UT) about 38.8 minutes after the trigger and stopped on November 18 04:23:04 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the enhanced X-ray afterglow position (Evans et al., GCN Circ. 18614). The estimated five sigma upper limit of the combined image (total exposure of 1200 sec) is ~18.3 using the USNO-B1 catalog.

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Jochen Greiner, last update: 26-Nov-2015 [Disclaimer]