Gamma-ray Burst 081118

(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:     Tue 18 Nov 08 14:57:54 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     334877,   Seg_Num: 0
GRB_RA:           82.590d {+05h 30m 22s} (J2000),
                  82.657d {+05h 30m 38s} (current),
                  82.210d {+05h 28m 50s} (1950)
GRB_DEC:         -43.302d {-43d 18' 07"} (J2000),
                 -43.296d {-43d 17' 44"} (current),
                 -43.339d {-43d 20' 19"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=3299 [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:        14788 TJD;   323 DOY;   08/11/18
GRB_TIME:        53796.73 SOD {14:56:36.73} UT
GRB_PHI:         -170.25 [deg]
GRB_THETA:        38.66 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    15.02 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +4  +0  +0 +37  +0 
SUN_POSTN:       234.34d {+15h 37m 22s}  -19.40d {-19d 24' 16"}
SUN_DIST:        112.12 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.84d {+08h 51m 23s}  +18.00d {+17d 59' 56"}
MOON_DIST:        76.63 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.90,-32.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       76.45,-66.39 [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 = 155.17,-16.15 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 14:59:40 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     334877,   Seg_Num: 0
GRB_RA:           82.5906d {+05h 30m 21.74s} (J2000),
                  82.6582d {+05h 30m 37.96s} (current),
                  82.2103d {+05h 28m 50.47s} (1950)
GRB_DEC:         -43.3000d {-43d 17' 59.9"} (J2000),
                 -43.2937d {-43d 17' 37.1"} (current),
                 -43.3368d {-43d 20' 12.5"} (1950)
GRB_ERROR:       6.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       6.01e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.74 [sigma]
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53950.03 SOD {14:59:10.03} UT,   153.3 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.24 261.42 243.51
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       234.34d {+15h 37m 23s}  -19.41d {-19d 24' 17"}
SUN_DIST:        112.12 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.86d {+08h 51m 27s}  +17.99d {+17d 59' 34"}
MOON_DIST:        76.63 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.90,-32.49 [deg] galactic lon,lat of the burst
ECL_COORDS:       76.45,-66.39 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.13 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 14:59:53 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     334877,   Seg_Num: 0
GRB_RA:           82.5906d {+05h 30m 21.7s} (J2000),
                  82.6582d {+05h 30m 37.9s} (current),
                  82.2103d {+05h 28m 50.4s} (1950)
GRB_DEC:         -43.3000d {-43d 17' 59.9"} (J2000),
                 -43.2937d {-43d 17' 37.1"} (current),
                 -43.3368d {-43d 20' 12.5"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       33 [cnts]
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53950.03 SOD {14:59:10.03} UT,   153.3 [sec] since BAT Trigger Time
CENTROID_X:      314.86,  raw= 315  [pixels]
CENTROID_Y:      321.89,  raw= 322  [pixels]
ROLL:            151.18 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   56.32
GRB_POS_XRT_Z:   29.62
IMAGE_URL:       sw00334877000msxps_rw.img
SUN_POSTN:       234.35d {+15h 37m 23s}  -19.41d {-19d 24' 17"}
SUN_DIST:        112.12 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.86d {+08h 51m 27s}  +17.99d {+17d 59' 31"}
MOON_DIST:        76.63 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.90,-32.49 [deg] galactic lon,lat of the burst
ECL_COORDS:       76.45,-66.39 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:00:00 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     334877,   Seg_Num: 0
GRB_RA:           82.5906d {+05h 30m 21.7s} (J2000),
                  82.6582d {+05h 30m 37.9s} (current),
                  82.2103d {+05h 28m 50.4s} (1950)
GRB_DEC:         -43.3000d {-43d 17' 59.9"} (J2000),
                 -43.2937d {-43d 17' 37.1"} (current),
                 -43.3368d {-43d 20' 12.5"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       33 [cnts]
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53950.03 SOD {14:59:10.03} UT,   153.3 [sec] since BAT Trigger Time
CENTROID_X:      314.86,  raw= 315  [pixels]
CENTROID_Y:      321.89,  raw= 322  [pixels]
ROLL:            151.18 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   56.32
GRB_POS_XRT_Z:   29.62
IMAGE_URL:       sw00334877000msxps_rw.img
SUN_POSTN:       234.35d {+15h 37m 23s}  -19.41d {-19d 24' 17"}
SUN_DIST:        112.12 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.86d {+08h 51m 28s}  +17.99d {+17d 59' 30"}
MOON_DIST:        76.63 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.90,-32.49 [deg] galactic lon,lat of the burst
ECL_COORDS:       76.45,-66.39 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:00:50 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     334877,   Seg_Num: 0
GRB_RA:           82.590d {+05h 30m 22s} (J2000),
                  82.657d {+05h 30m 38s} (current),
                  82.210d {+05h 28m 50s} (1950)
GRB_DEC:         -43.302d {-43d 18' 07"} (J2000),
                 -43.296d {-43d 17' 44"} (current),
                 -43.339d {-43d 20' 19"} (1950)
GRB_DATE:        14788 TJD;   323 DOY;   08/11/18
GRB_TIME:        53796.73 SOD {14:56:36.73} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -170.25 [deg]
GRB_THETA:        38.66 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    15.02 [sigma]
LC_URL:          sw00334877000msb.lc
SUN_POSTN:       234.35d {+15h 37m 23s}  -19.41d {-19d 24' 18"}
SUN_DIST:        112.12 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.87d {+08h 51m 30s}  +17.99d {+17d 59' 19"}
MOON_DIST:        76.63 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.90,-32.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       76.45,-66.39 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is 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 = 155.17,-16.15 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:02:15 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.578d {+05h 30m 19s} (J2000)
POINT_DEC:       -43.315d {-43d 18' 52"} (J2000)
POINT_ROLL:      151.174d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53960.44 SOD {14:59:20.44} UT,   163.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.567
N_STARS:         35
X_OFFSET:        372 [pixels]
Y_OFFSET:        471 [pixels]
X_MAX:           1331 [pixels]
Y_MAX:           1430 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00334877000msufc0163.fits
SUN_POSTN:       234.35d {+15h 37m 23s}  -19.41d {-19d 24' 19"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.89d {+08h 51m 33s}  +17.98d {+17d 59' 02"}
MOON_DIST:        76.65 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.42,-66.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:02:55 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.578d {+05h 30m 19s} (J2000)
POINT_DEC:       -43.315d {-43d 18' 52"} (J2000)
POINT_ROLL:      151.174d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53960.44 SOD {14:59:20.44} UT,   163.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.567
N_STARS:         35
X_OFFSET:        372 [pixels]
Y_OFFSET:        471 [pixels]
X_MAX:           1331 [pixels]
Y_MAX:           1430 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00334877000msufc0163.fits
SUN_POSTN:       234.35d {+15h 37m 23s}  -19.41d {-19d 24' 19"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.89d {+08h 51m 34s}  +17.98d {+17d 58' 53"}
MOON_DIST:        76.65 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.42,-66.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:03:50 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.578d {+05h 30m 19s} (J2000)
POINT_DEC:       -43.315d {-43d 18' 52"} (J2000)
ROLL:            151.174d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53960.44 SOD {14:59:20.44} UT,   163.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     248713163
X_OFFSET:        692 [pixels]
Y_OFFSET:        791 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       951
BINNING_INDEX:   1
IM_URL:          sw00334877000msuni0163.fits
SUN_POSTN:       234.35d {+15h 37m 24s}  -19.41d {-19d 24' 20"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.90d {+08h 51m 36s}  +17.98d {+17d 58' 42"}
MOON_DIST:        76.66 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.42,-66.40 [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:     Tue 18 Nov 08 15:04:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.578d {+05h 30m 19s} (J2000)
POINT_DEC:       -43.315d {-43d 18' 52"} (J2000)
ROLL:            151.174d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  53960.44 SOD {14:59:20.44} UT,   163.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     248713163
X_OFFSET:        692 [pixels]
Y_OFFSET:        791 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       951
BINNING_INDEX:   1
IM_URL:          sw00334877000msuni0163.fits
SUN_POSTN:       234.35d {+15h 37m 24s}  -19.41d {-19d 24' 20"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.91d {+08h 51m 38s}  +17.98d {+17d 58' 36"}
MOON_DIST:        76.66 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.42,-66.40 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:05:09 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     334877,   Seg_Num: 0
GRB_RA:           82.5925d {+05h 30m 22.20s} (J2000),
                  82.6601d {+05h 30m 38.42s} (current),
                  82.2122d {+05h 28m 50.92s} (1950)
GRB_DEC:         -43.3005d {-43d 18' 01.7"} (J2000),
                 -43.2942d {-43d 17' 38.9"} (current),
                 -43.3373d {-43d 20' 14.3"} (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:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  54051.00 SOD {15:00:51.00} UT,   254.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       234.35d {+15h 37m 24s}  -19.41d {-19d 24' 20"}
SUN_DIST:        112.12 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      132.91d {+08h 51m 39s}  +17.97d {+17d 58' 25"}
MOON_DIST:        76.64 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.90,-32.49 [deg] galactic lon,lat of the burst
ECL_COORDS:       76.45,-66.39 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.

GCN Circular #8524
E. A. Hoversten (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), M. Capalbi (ASDC), P.A. Curran (MSSL-UCL), M. De Pasquale (UCL-MSSL), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), D. Grupe (PSU), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB), J. P. Osborne (U Leicester), C. Pagani (PSU), D. M. Palmer (LANL), J. L. Racusin (PSU), P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-IASFPA), P. Schady (MSSL-UCL), R. L. C. Starling (U Leicester), G. Tagliaferri (INAF-OAB), E. Troja (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 14:56:36 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 081118 (trigger=334877). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 82.590, -43.302 which is
```
   RA(J2000)  =  05h 30m 22s
   Dec(J2000) = -43d 18' 07"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Even though this is an image trigger, there appears to be a peak of about 600 counts/sec starting 20 to 40 sec after the start of the trigger integration.
The XRT began observing the field at 14:59:10.0 UT, 153.3 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 82.59254, -43.30058 which is equivalent to:
```
   RA(J2000)  = 05h 30m 22.21s
   Dec(J2000) = -43d 18' 02.1"
```
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 8.4 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 3.74e+20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 6.01e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 164 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 0.04.
Burst Advocate for this burst is E. A. Hoversten (hoversten AT astro.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:14:05 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.575d {+05h 30m 18s} (J2000)
POINT_DEC:       -43.314d {-43d 18' 50"} (J2000)
POINT_ROLL:      151.179d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  54664.31 SOD {15:11:04.31} UT,   867.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.659
N_STARS:         132
X_OFFSET:        132 [pixels]
Y_OFFSET:        231 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1670 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00334877000msufc0867.fits
SUN_POSTN:       234.36d {+15h 37m 25s}  -19.41d {-19d 24' 26"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      133.00d {+08h 52m 00s}  +17.94d {+17d 56' 33"}
MOON_DIST:        76.68 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.41,-66.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:14:32 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.575d {+05h 30m 18s} (J2000)
POINT_DEC:       -43.314d {-43d 18' 50"} (J2000)
POINT_ROLL:      151.179d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  54664.31 SOD {15:11:04.31} UT,   867.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.659
N_STARS:         132
X_OFFSET:        132 [pixels]
Y_OFFSET:        231 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1670 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00334877000msufc0867.fits
SUN_POSTN:       234.36d {+15h 37m 25s}  -19.41d {-19d 24' 26"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      133.00d {+08h 52m 01s}  +17.94d {+17d 56' 28"}
MOON_DIST:        76.68 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.41,-66.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:15:20 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.575d {+05h 30m 18s} (J2000)
POINT_DEC:       -43.314d {-43d 18' 50"} (J2000)
ROLL:            151.179d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  54664.31 SOD {15:11:04.31} UT,   867.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     248713867
X_OFFSET:        691 [pixels]
Y_OFFSET:        790 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       851
Y_GRB_POS:       950
BINNING_INDEX:   1
IM_URL:          sw00334877000msuni0867.fits
SUN_POSTN:       234.36d {+15h 37m 25s}  -19.41d {-19d 24' 26"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      133.01d {+08h 52m 03s}  +17.94d {+17d 56' 18"}
MOON_DIST:        76.68 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.41,-66.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 18 Nov 08 15:15:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     334877,   Seg_Num: 0
POINT_RA:         82.575d {+05h 30m 18s} (J2000)
POINT_DEC:       -43.314d {-43d 18' 50"} (J2000)
ROLL:            151.179d
IMG_START_DATE:  14788 TJD;   323 DOY;   08/11/18
IMG_START_TIME:  54664.31 SOD {15:11:04.31} UT,   867.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     248713867
X_OFFSET:        691 [pixels]
Y_OFFSET:        790 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       851
Y_GRB_POS:       950
BINNING_INDEX:   1
IM_URL:          sw00334877000msuni0867.fits
SUN_POSTN:       234.36d {+15h 37m 26s}  -19.41d {-19d 24' 27"}
SUN_DIST:        112.11 [deg]   Sun_angle= 10.1 [hr] (West of Sun)
MOON_POSTN:      133.02d {+08h 52m 04s}  +17.94d {+17d 56' 14"}
MOON_DIST:        76.69 [deg]
MOON_ILLUM:      64 [%]
GAL_COORDS:      248.91,-32.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       76.41,-66.40 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #8525
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 4848 s of XRT Photon Counting mode data and 4 UVOT images for GRB 081118, 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 = 82.5928, -43.3009 which is equivalent to:
```
RA (J2000): 05h 30m 22.28s
Dec (J2000): -43d 18' 03.1"
```
with an uncertainty of 2.0 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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method.
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #8526
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 081118 (trigger #334877) (Hoversten, et al., GCN Circ. 8524). The BAT ground-calculated position is RA, Dec = 82.572, -43.305 deg, which is
```
   RA(J2000)  =  05h 30m 17.3s 
   Dec(J2000) = -43d 18' 16.2" 
```
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 61%.
The mask-weighted light curve shows a roughly symmetrical peak starting at ~T+10 sec, peaking at ~T+25 sec, and ending at ~T+105 sec. T90 (15-350 keV) is 67+- 28 sec (estimated error including systematics).
The time-averaged spectrum from T+19.6 to T+118.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.10 +- 0.16. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+46.97 sec in the 15-150 keV band is 0.6 +- 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/334877/BA/
GCN Circular #8527
E. A. Hoversten (PSU) reports on behalf of the Swift UVOT team:
The Swift/UVOT began settled observations of the field of GRB 081118 150s after the BAT trigger (Hoversten et al., GCN 8524). We do not detect any source at the enhanced Swift XRT position (Evans et al., GCN 8525). UVOT magnitude 3-sigma upper limits are reported in the following table:
```
Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white       150      300     147      > 21.32
white       854     1004     147      > 21.29
white      5726     5926     196      > 21.50
v          6137     6337     196      > 19.79
b          5522     5721     196      > 20.82
u          5316     5515     196      > 20.49
uvw1       5111     5310     196      > 20.26
uvm2       4905     5105     196      > 19.88
uvw2       5933     6132     196      > 20.24
```
The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.04 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular #8528
P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-OAR), S. Covino (INAF-OAB), S. Piranomonte (INAF-OAR), R. Salvaterra (INAF-OAB), C. Thone (INAF-OAB), G. Chincarini (Un. Bicocca) report on behalf of the MISTICI collaboration:
We observed the field of GRB 081118 (Hoversten et al. GCN 8524) with the ESO-VLT equipped with the FORS2 camera on Nov 19.0431 UT (about 10 hours after the burst). We detect an object in our R-band images at the edge of the refined XRT error box (Evans et al. GCN 8525). The object is around R ~ 22.5. At present it is not possible to say if it is variable or not. Object coordinates are (J2000):
```
R.A. = 05:30:22.18
Dec = -43:18:05.3
```
+/- 0.5". Further analysis is ongoing.
We acknowledge support from the ESO staff, in particular Antonio de Ugarte Postigo.
GCN Circular #8529
S. Loew, J. Greiner, A. Yoldas (all MPE Garching), A. Kuepcue Yoldas (ESO), G. Szokoly (Eoetvoes Univ., Budapest, and MPE) report for the GROND team:
We observed the field of GRB 081118 (Swift trigger 334877; Hoversten et al., GCN #8524) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile). Observations started at 00:35 UT on November 19th, 2008, 9.6 hr post-burst, when the GRB location was becoming visible at 20 degrees above horizon. Observations were performed at an average seeing of 1.0".
We detect the source reported by D'Avanzo et al. (GCN #8528) at the edge of the astrometrically corrected 2.0'' Swift-XRT error circle (Evans et al., GCN #8525). Based on a 20 min exposure at mid-time 1:55 UT, we estimate preliminary magnitudes (all in AB system) of
```
g' ~ 23.3 mag,     
r' ~ 23.0 mag,     
i' ~ 22.5 mag,     
z' ~ 22.0 mag,
J  ~ 21.6 mag,     
H  ~ 21.2 mag and  
K  ~ 20.6 mag      
```
with errors of +/- 0.2. These magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars, and are not corrected for the galactic foreground extinction of E(B-V)= 0.04 (Schlegel et al. 1998).
The object clearly decayed by 0.6 mag over the course of 1.5 hrs, thus it is suggested as the couterpart of GRB 081118.
The spectral energy distribution is consistent with a power law, so the g'-band detection implies a redshift of this GRB smaller than 3.5.
GCN Circular #8530
L. Vetere, E. Hoversten (PSU) report on behalf of the Swift-XRT team.
The Swift-XRT started observing the field of GRB 081118 (trigger=334877, Hoversten et al., GCN 8525) at 14:59:10.0 UT, 153.3 s after the BAT trigger. The XRT observed the GRB in Windowed Timing (WT) mode until 216 s after the trigger and Photon Counting (PC) mode thereafter.
The X-ray light curve from the first three orbits can be modelled with a broken powerlaw with an initial rapid decay (slope of 4.8+/-1.0), a break time of 580 s, followed by a shallower decay (slope of 0.6+/-0.3).
The spectrum of the WT data can be well fit by an absorbed powerlaw with a photon index of 2.6 +/- 0.3 and an absorbing equivalent hydrogen column density consistent with the Galactic one in the GRB direction (3.7e20 cm^-2; Kalberla et al. 2005). The observed (unabsorbed) 0.3-10 keV flux is 1.79 (2.28) x 10^-10 erg cm^-2 s^-1.
The PC spectrum (T+250 s to T+19 ks) is best fit with a photon index of 2.5 +/- 0.3 and an absorbing equivalent hydrogen column density consistent with the Galactic one in the GRB direction (3.7e20 cm^-2; Kalberla et al. 2005). The observed (unabsorbed) 0.3-10 keV flux over this interval is 7.6 (9.4) x 10^-13 erg cm^-2 s^-1.
Assuming the X-ray emission from the burst continues to decline at the same rate we predict an XRT count rate of 0.002 count s^-1 at T+24 hour, or an observed 0.3-10 keV X-ray flux of 5.2 x 10^-14 erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular #8531
V. D'Elia (INAF-OAR), C. C. Thoene (INAF-OAB), A. De Ugarte Postigo (ESO), P. D'Avanzo, S. Covino (INAF-OAB), S. Piranomonte (INAF-OAR), R. Salvaterra (INAF-OAB), G. Chincarini (Univ. Bicocca) report on behalf of the MISTICI collaboration:
We observed the optical afterglow candidate of GRB 081118 (D'Avanzo et al. GCN 8528; Loew et al. GCN 8529) with the ESO-VLT equipped with the FORS2 camera starting on Nov 19.1166 (about 12 hours after the burst) in spectroscopic mode. We took 2x30 min spectra covering the range 4300-9000 Angstrom (based on a preliminary wavelength calibration) with a resolution of R=440.
We detect a broad absorption feature around lambda_obs = 4350 Angstrom. Interpreting this feature as Ly-alpha absorption the inferred redshift is z = 2.58. At this redshift we also detect the SiII (1260), SiII (1304), CII (1334), SiIV (1393,1402) doublet, SiII (1526), CIV (1548,1550) doublet, FeII (1608), AlII (1670), SiII (1808) and AlIII (1854).
We acknowledge support from the ESO staff.
GCN Circular #8532
Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward optically bright GRB 08118 (GCN 8524) at a frequency of 8.46 GHz on 2008 Nov 20.35 UT. The GRB radio afterglow is undetected and the peak radio flux at the ESO-VLT optical afterglow position=20 (GCN 8528) is -70 =B1 60 uJy.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Circular #8535
H.hayasi, N.Ohmori, K.Kono H.Tanaka, R.Hara, M.Yamauchi, E.Sonoda, (University of Miyazaki)
We have observed the field covering the error circle of GRB081118(GCN 8524, Hoversten et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 14:57:54 UT, 38.1 min after the Swift-BAT trigger time.
We have compared our data of 30 sec exposures with the USNO-A2.0 catalog.there is no new source at the reported position. (GCN 8524, Hoversten et al. GCN 8526, Palmer et al. GCN 8528, D'Avanzo et al.)
the upper limits are as follows:
```
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
15:35:58 15:36:28 1  16.7
15:35:58 16:11:50 32 17.6
---------------------------------------------------------------
```
GCN Circular #8642
Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope National Facility), Steven Tingay (Curtin Institute of Radio Astronomy), Chris Phillips (Australia Telescope National Facility), Gregory Taylor (University of New Mexico), Mark Wieringa (Australia Telescope National Facility) and Ralph Martin (Perth Observatory) report:
We observed the VLT position of the GRB 081118 optical afterglow (GCN 8528) at 4.800 and 4.928 GHz with the Australia Telescope Compact Array (ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30 UT, November 25, 2008.
We did not detect a radio source at the optical afterglow position of the GRB 081118 (GCN 8528). The data at 4.800 and 4.928 GHz were merged and the radio flux density at the afterglow position found out to be -89 +/- 5.6 uJy/beam (1-sigma).
The Australia Telescope Compact Array (/ Parkes telescope / Mopra telescope / Long Baseline Array) is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.
See the 4.800 & 4.928 GHz combined image at:
http://cira.ivec.org/dokuwiki/doku.php/grb/grb081118_field_image
GCN Report 181.1
GCN_Report 181.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_181_1.pdf by E.A. Hoversten at PSU titled: "Final Swift report on GRB 081118"
GCN Circular #8675
Subject: GRB 081118: Zadko observations From: D.M Coward at UWA
D.M. Coward, T. Vaalsta, J. Zadko, A. Imerito, D. Blair, R. Burman, P. Lucas, S. Gordon, K. Frost, A. Fletcher (University of Western Australia) M. Todd, M. Zadnik (Curtin University) M. Boer, A. Klotz (TAROT)
On 18 Nov, the Zadko Telescope team observed the XRT field of GRB 081118 reported by P. Evans (GCN 8525) using the 1 meter Zadko Telescope (in very early commissioning mode). Imaging commenced approx 1.96 hr post burst trigger using an unfiltered integrating CCD video camera and continued over a period of 1 hr. The OA candidate reported by GCN 8529 is seen in a selected stack of 40 x 5 second exposures, though it is near the detection limit. We do not have absolute standard star photometric calibration. Using nearby USNO-B1 stars we estimate the limiting magnitude of the OA to be in the range 20.9 +- 0.5.
This message is quotable in publications.
David Coward and Timo Vaalsta report on behalf of the UWA Zadko Telescope Team.

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Jochen Greiner, last update: 16-Dec-2008 [Disclaimer]