Gamma-ray Burst 130816B

(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 16 Aug 13 04:54:02 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     566561,   Seg_Num: 0
GRB_RA:          170.093d {+11h 20m 22s} (J2000),
                 170.247d {+11h 20m 59s} (current),
                 169.529d {+11h 18m 07s} (1950)
GRB_DEC:         -57.558d {-57d 33' 28"} (J2000),
                 -57.633d {-57d 37' 57"} (current),
                 -57.284d {-57d 17' 02"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5465 [cnts]    Image_Peak=302 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   137     E_range: 15-50 keV
BKG_INTEN:       33847 [cnts]
BKG_TIME:        17605.08 SOD {04:53:25.08} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16520 TJD;   228 DOY;   13/08/16
GRB_TIME:        17618.58 SOD {04:53:38.58} UT
GRB_PHI:         -131.52 [deg]
GRB_THETA:        14.21 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.06 [sigma]
IMAGE_SIGNIF:    10.39 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +1  +0  +0  +1 -27  +0 
SUN_POSTN:       145.83d {+09h 43m 18s}  +13.69d {+13d 41' 08"}
SUN_DIST:         74.11 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.64d {+17h 02m 33s}  -19.73d {-19d 44' 00"}
MOON_DIST:        70.99 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.93,  3.18 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      205.41,-54.19 [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 = 60.09,-19.47 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 04:54:58 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.102d {+11h 20m 25s} (J2000)
POINT_DEC:       -57.574d {-57d 34' 25"} (J2000)
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17688.81 SOD {04:54:48.81} UT,   70.2 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 04:57:32 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     566561,   Seg_Num: 0
GRB_RA:          170.093d {+11h 20m 22s} (J2000),
                 170.247d {+11h 20m 59s} (current),
                 169.529d {+11h 18m 07s} (1950)
GRB_DEC:         -57.558d {-57d 33' 28"} (J2000),
                 -57.633d {-57d 37' 57"} (current),
                 -57.284d {-57d 17' 02"} (1950)
GRB_DATE:        16520 TJD;   228 DOY;   13/08/16
GRB_TIME:        17618.58 SOD {04:53:38.58} UT
TRIGGER_INDEX:   137
GRB_PHI:         -131.52 [deg]
GRB_THETA:        14.21 [deg]
DELTA_TIME:      -70.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.06 [sigma]
IMAGE_SIGNIF:    10.39 [sigma]
LC_URL:          sw00566561000msb.lc
SUN_POSTN:       145.83d {+09h 43m 19s}  +13.68d {+13d 41' 05"}
SUN_DIST:         74.11 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.68d {+17h 02m 42s}  -19.73d {-19d 44' 04"}
MOON_DIST:        71.01 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.93,  3.18 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      205.41,-54.19 [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 = 60.09,-19.47 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 05:00:03 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.102d {+11h 20m 25s} (J2000)
POINT_DEC:       -57.574d {-57d 34' 25"} (J2000)
POINT_ROLL:      335.435d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17693.71 SOD {04:54:53.71} UT,   75.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.750
N_STARS:         190
X_OFFSET:        593 [pixels]
Y_OFFSET:        484 [pixels]
X_MAX:           1552 [pixels]
Y_MAX:           1443 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00566561000msufc0075.fits
SUN_POSTN:       145.83d {+09h 43m 19s}  +13.68d {+13d 41' 03"}
SUN_DIST:         74.13 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.70d {+17h 02m 49s}  -19.74d {-19d 44' 06"}
MOON_DIST:        71.02 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.94,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.43,-54.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 05:00:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.102d {+11h 20m 25s} (J2000)
POINT_DEC:       -57.574d {-57d 34' 25"} (J2000)
POINT_ROLL:      335.435d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17693.71 SOD {04:54:53.71} UT,   75.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.750
N_STARS:         190
X_OFFSET:        593 [pixels]
Y_OFFSET:        484 [pixels]
X_MAX:           1552 [pixels]
Y_MAX:           1443 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00566561000msufc0075.fits
SUN_POSTN:       145.83d {+09h 43m 19s}  +13.68d {+13d 41' 03"}
SUN_DIST:         74.13 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.71d {+17h 02m 50s}  -19.74d {-19d 44' 07"}
MOON_DIST:        71.02 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.94,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.43,-54.20 [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 16 Aug 13 05:00:47 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     566561,   Seg_Num: 0
GRB_RA:          170.0184d {+11h 20m 04.41s} (J2000),
                 170.1724d {+11h 20m 41.37s} (current),
                 169.4555d {+11h 17m 49.32s} (1950)
GRB_DEC:         -57.5582d {-57d 33' 29.5"} (J2000),
                 -57.6329d {-57d 37' 58.4"} (current),
                 -57.2843d {-57d 17' 03.3"} (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:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17709.00 SOD {04:55:09.00} UT,   90.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       145.83d {+09h 43m 19s}  +13.68d {+13d 41' 03"}
SUN_DIST:         74.09 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.71d {+17h 02m 51s}  -19.74d {-19d 44' 07"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.89,  3.16 [deg] galactic lon,lat of the burst
ECL_COORDS:      205.36,-54.22 [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:     Fri 16 Aug 13 05:02:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.102d {+11h 20m 25s} (J2000)
POINT_DEC:       -57.574d {-57d 34' 25"} (J2000)
ROLL:            335.435d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17693.71 SOD {04:54:53.71} UT,   75.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     398321704
X_OFFSET:        912 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1072
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw00566561000msuni0086.fits
SUN_POSTN:       145.83d {+09h 43m 20s}  +13.68d {+13d 41' 02"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.72d {+17h 02m 54s}  -19.74d {-19d 44' 09"}
MOON_DIST:        71.03 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.94,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.43,-54.20 [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 16 Aug 13 05:02:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.102d {+11h 20m 25s} (J2000)
POINT_DEC:       -57.574d {-57d 34' 25"} (J2000)
ROLL:            335.435d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17693.71 SOD {04:54:53.71} UT,   75.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     398321704
X_OFFSET:        912 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1072
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw00566561000msuni0086.fits
SUN_POSTN:       145.83d {+09h 43m 20s}  +13.68d {+13d 41' 02"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.73d {+17h 02m 54s}  -19.74d {-19d 44' 09"}
MOON_DIST:        71.03 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.94,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.43,-54.20 [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:     Fri 16 Aug 13 05:08:01 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.108d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
POINT_ROLL:      335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17906.04 SOD {04:58:26.04} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.218
N_STARS:         190
X_OFFSET:        353 [pixels]
Y_OFFSET:        244 [pixels]
X_MAX:           1792 [pixels]
Y_MAX:           1683 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00566561000msufc0287.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 57"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.79d {+17h 03m 09s}  -19.74d {-19d 44' 14"}
MOON_DIST:        71.06 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 05:08:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.108d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
POINT_ROLL:      335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17906.04 SOD {04:58:26.04} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.218
N_STARS:         190
X_OFFSET:        353 [pixels]
Y_OFFSET:        244 [pixels]
X_MAX:           1792 [pixels]
Y_MAX:           1683 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00566561000msufc0287.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 57"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.79d {+17h 03m 10s}  -19.74d {-19d 44' 15"}
MOON_DIST:        71.06 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [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 16 Aug 13 05:09:23 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     566561,   Seg_Num: 0
GRB_RA:          170.0166d {+11h 20m 03.98s} (J2000),
                 170.1706d {+11h 20m 40.94s} (current),
                 169.4537d {+11h 17m 48.89s} (1950)
GRB_DEC:         -57.5572d {-57d 33' 25.9"} (J2000),
                 -57.6319d {-57d 37' 54.8"} (current),
                 -57.2833d {-57d 16' 59.7"} (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:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17709.00 SOD {04:55:09.00} UT,   90.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 56"}
SUN_DIST:         74.09 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.80d {+17h 03m 12s}  -19.74d {-19d 44' 16"}
MOON_DIST:        71.12 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.89,  3.16 [deg] galactic lon,lat of the burst
ECL_COORDS:      205.36,-54.22 [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:     Fri 16 Aug 13 05:09:37 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.108d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
ROLL:            335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17906.04 SOD {04:58:26.04} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     398321916
X_OFFSET:        912 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1072
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw00566561000msuni0298.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 56"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.80d {+17h 03m 13s}  -19.74d {-19d 44' 16"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [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 Circular #15099
M. Stamatikos (OSU/NASA/GSFC), P. D'Avanzo (INAF-OAB), M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift Team:
At 04:53:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130816B (trigger=566561). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 170.093, -57.558 which is
```
   RA(J2000) = 11h 20m 22s
   Dec(J2000) = -57d 33' 28"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak structure with a duration of about 20 sec. The peak count rate was ~2440 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 04:54:48.8 UT, 70.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 170.01845, -57.55829 which is equivalent to:
```
   RA(J2000)  = 11h 20m 04.43s
   Dec(J2000) = -57d 33' 29.8"
```
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 143 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. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 4.04 x 10^21 cm^-2 (Kalberla et al. 2005).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 75 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. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the large, but uncertain extinction expected.
Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 05:09:56 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.108d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
ROLL:            335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  17906.04 SOD {04:58:26.04} UT,   287.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     398321916
X_OFFSET:        912 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1072
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw00566561000msuni0298.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 56"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.81d {+17h 03m 14s}  -19.74d {-19d 44' 16"}
MOON_DIST:        71.07 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [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:     Fri 16 Aug 13 05:12:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.109d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
POINT_ROLL:      335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  18487.07 SOD {05:08:07.07} UT,   868.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.468
N_STARS:         190
X_OFFSET:        353 [pixels]
Y_OFFSET:        244 [pixels]
X_MAX:           1792 [pixels]
Y_MAX:           1683 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00566561000msufc0868.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 53"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.84d {+17h 03m 21s}  -19.74d {-19d 44' 19"}
MOON_DIST:        71.08 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 16 Aug 13 05:13:10 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.109d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
POINT_ROLL:      335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  18487.07 SOD {05:08:07.07} UT,   868.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.468
N_STARS:         190
X_OFFSET:        353 [pixels]
Y_OFFSET:        244 [pixels]
X_MAX:           1792 [pixels]
Y_MAX:           1683 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00566561000msufc0868.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 53"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.84d {+17h 03m 22s}  -19.74d {-19d 44' 19"}
MOON_DIST:        71.09 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [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 16 Aug 13 05:14:08 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.109d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
ROLL:            335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  18487.07 SOD {05:08:07.07} UT,   868.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     398322497
X_OFFSET:        912 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1072
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw00566561000msuni0879.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 52"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.85d {+17h 03m 24s}  -19.74d {-19d 44' 20"}
MOON_DIST:        71.09 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [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 16 Aug 13 05:14:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     566561,   Seg_Num: 0
POINT_RA:        170.109d {+11h 20m 26s} (J2000)
POINT_DEC:       -57.575d {-57d 34' 28"} (J2000)
ROLL:            335.428d
IMG_START_DATE:  16520 TJD;   228 DOY;   13/08/16
IMG_START_TIME:  18487.07 SOD {05:08:07.07} UT,   868.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     398322497
X_OFFSET:        912 [pixels]
Y_OFFSET:        803 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1072
Y_GRB_POS:       963
BINNING_INDEX:   1
IM_URL:          sw00566561000msuni0879.fits
SUN_POSTN:       145.84d {+09h 43m 21s}  +13.68d {+13d 40' 52"}
SUN_DIST:         74.12 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      255.85d {+17h 03m 25s}  -19.74d {-19d 44' 21"}
MOON_DIST:        71.09 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      290.95,  3.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      205.44,-54.20 [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 #15102
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 1915 s of XRT Photon Counting mode data and 2 UVOT images for GRB 130816B, 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 = 170.01621, -57.55740 which is equivalent to:
```
RA (J2000): 11h 20m 3.89s
Dec (J2000): -57d 33' 26.7"
```
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 #15103
B.P. Gompertz (U. Leicester), V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and M. Stamatikos report on behalf of the Swift-XRT team:
We have analysed 7.7 ks of XRT data for GRB 130816B (Stamatikos et al. GCN Circ. 15099), from 77 s to 24.0 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 15102).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.98 (+0.13, -0.11).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.1 (+0.5, -0.4). The best-fitting absorption column is 5.3 (+2.8, -1.3) x 10^21 cm^-2, consistent with the Galactic value of 4.0 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.6 x 10^-11 (8.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     5.3 (+2.8, -1.3) x 10^21 cm^-2
Galactic foreground: 4.0 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.1 (+0.5, -0.4)
```
If the light curve continues to decay with a power-law decay index of 0.98, the count rate at T+24 hours will be 5.8 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x 10^-14 (4.9 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00566561.
This circular is an official product of the Swift-XRT team.
GCN Circular #15107
K. Varela (MPE Garching), S. Klose (TLS Tautenburg) and J. Greiner (both MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 130816B (Stamatikos et al., GCN #15099) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
Observations started at 23:12 UT on 16 August 2013, 18.3 hours after the GRB trigger. They were performed at an average seeing of 1.6" and at and average airmass of 2.20. We find a source inside the 1.9" Swift-XRT error circle (Osborne et al., GCN #15102) at coordinates
```
RA(J2000.0) = 11:20:03.96
DEC (J200.0) = -57:33:27.1
```
with an uncertainty of 0.5" in each coordinate.
Based on the first 460 sec g'r'i'z and 480 sec JHK exposure, we estimate preliminary magnitudes (all in AB) of
```
g' > 23.5 mag
r' = 23.1 +/- 0.2 mag,
i' = 22.5 +/- 0.2 mag,
z' = 21.6 +/- 0.1 mag,
J = 20.5 +/- 0.3 mag,
H = 20.5 +/- 0.3 mag,
K = 19.9 +/- 0.4 mag,
```
calibrated against GROND zero points (griz) and 2MASS (JHK) and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.56 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #15108
M. Stamatikos (OSU), 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), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130816B (trigger #566561) (Stamatikos, et al., GCN Circ. 15099). The BAT ground-calculated position is RA, Dec = 170.049, -57.527 deg which is
```
   RA(J2000)  =  11h 20m 11.8s
   Dec(J2000) = -57d 31' 37.7"
```
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).The partial coding was 98%.
BAT mask-weighted light curve shows a single peak starting from ~T-10 sec peaking around T+0 sec and ending at ~T+4 sec. T90 (15-350 keV) is 10.00 +- 3.61 sec (estimated error including systematics).
The time-averaged spectrum from T-6.50 to T+6.50 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.45 +- 0.93, and Epeak of 47.3 +- 10.8 keV (chi squared 35.98 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 2.7 +- 0.4 x 10^-07 erg/cm2 and the 1-sec peak flux measured from T+0.50 sec in the 15-150 keV band is 0.9 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.82 +- 0.17 (chi squared 44.98 for 57 d.o.f.). 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/566561/BA/
GCN Circular #15110
S. T. Holland (STScI) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 130816B starting 75 s after the BAT trigger (Stamatikos et al. 2013, GCNC 15099). We do not detect any new source consistent with the GROND afterglow position (Varela et al. 2013, GCNC 15107) in any of the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the finding chart (FC) exposures and initial summed exposures are presented below.
```
---------------------------------------------------
Filter       TSTART      TSTOP    Exposure      Mag
---------------------------------------------------
white (FC)       75        225         147    >20.7
    u (FC)      287        537         246    >19.9
---------------------------------------------------
    v           618     12,639        1295    >20.4
    b           543       7299         530    >20.7
    u           692     19,298         923    >20.5
 uvw1           667     18,676        1238    >20.8
 uvm2           642     13,534        1227    >20.8
 uvw2           593     24,128         882    >20.7
white           567       7498         672    >21.5
---------------------------------------------------
```
The quoted upper limits have not been corrected for the expected extinction due to the Galactic reddening along the line of sight to this burst of E(B-V) = 0.50 mag (Schlafly et al. 2011, ApJS, 737, 103). GRB 130816B was 3 degrees above the Galactic Plane, so this extinction value is highly uncertain.

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Jochen Greiner, last update: 19-Aug-2013 [Disclaimer]