Gamma-ray Burst 120816A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:19:15 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     531223,   Seg_Num: 0
GRB_RA:          282.126d {+18h 48m 30s} (J2000),
                 282.296d {+18h 49m 11s} (current),
                 281.452d {+18h 45m 48s} (1950)
GRB_DEC:          -6.979d {-06d 58' 43"} (J2000),
                  -6.964d {-06d 57' 50"} (current),
                  -7.036d {-07d 02' 08"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       17536 [cnts]    Image_Peak=194 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   295     E_range: 15-50 keV
BKG_INTEN:       161716 [cnts]
BKG_TIME:        69454.45 SOD {19:17:34.45} UT
BKG_DUR:         40 [sec]
GRB_DATE:        16155 TJD;   229 DOY;   12/08/16
GRB_TIME:        69514.74 SOD {19:18:34.74} UT
GRB_PHI:         141.65 [deg]
GRB_THETA:        46.65 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     10.24 [sigma]
IMAGE_SIGNIF:    6.94 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +1  -3  +0  +1 +71  +0 
SUN_POSTN:       146.61d {+09h 46m 27s}  +13.42d {+13d 25' 04"}
SUN_DIST:        135.97 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.81d {+08h 59m 15s}  +12.17d {+12d 10' 15"}
MOON_DIST:       147.54 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.38, -2.53 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      282.52, 15.93 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 22.61,19.07 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:20:57 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.116d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.963d {-06d 57' 44"} (J2000)
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69647.33 SOD {19:20:47.33} UT,   132.6 [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:     Thu 16 Aug 12 19:22:32 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     531223,   Seg_Num: 0
GRB_RA:          282.126d {+18h 48m 30s} (J2000),
                 282.296d {+18h 49m 11s} (current),
                 281.452d {+18h 45m 48s} (1950)
GRB_DEC:          -6.979d {-06d 58' 43"} (J2000),
                  -6.964d {-06d 57' 50"} (current),
                  -7.036d {-07d 02' 08"} (1950)
GRB_DATE:        16155 TJD;   229 DOY;   12/08/16
GRB_TIME:        69514.74 SOD {19:18:34.74} UT
TRIGGER_INDEX:   295
GRB_PHI:         141.65 [deg]
GRB_THETA:        46.65 [deg]
DELTA_TIME:      51.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     10.24 [sigma]
IMAGE_SIGNIF:    6.94 [sigma]
LC_URL:          sw00531223000msb.lc
SUN_POSTN:       146.61d {+09h 46m 28s}  +13.42d {+13d 25' 02"}
SUN_DIST:        135.97 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.84d {+08h 59m 22s}  +12.16d {+12d 09' 41"}
MOON_DIST:       147.51 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.38, -2.53 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      282.52, 15.93 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 22.61,19.07 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:25:25 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     531223,   Seg_Num: 0
GRB_RA:          282.1442d {+18h 48m 34.60s} (J2000),
                 282.3143d {+18h 49m 15.43s} (current),
                 281.4704d {+18h 45m 52.89s} (1950)
GRB_DEC:          -6.9375d {-06d 56' 15.0"} (J2000),
                  -6.9226d {-06d 55' 21.4"} (current),
                  -6.9945d {-06d 59' 40.0"} (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:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69667.00 SOD {19:21:07.00} UT,   152.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       146.62d {+09h 46m 28s}  +13.42d {+13d 24' 60"}
SUN_DIST:        135.97 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.87d {+08h 59m 28s}  +12.15d {+12d 09' 12"}
MOON_DIST:       147.50 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.43, -2.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      282.55, 15.97 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:26:26 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.116d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 40"} (J2000)
POINT_ROLL:      282.097d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69649.35 SOD {19:20:49.35} UT,   134.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.605
N_STARS:         190
X_OFFSET:        341 [pixels]
Y_OFFSET:        500 [pixels]
X_MAX:           1300 [pixels]
Y_MAX:           1459 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00531223000msufc0134.fits
SUN_POSTN:       146.62d {+09h 46m 28s}  +13.42d {+13d 24' 59"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.88d {+08h 59m 30s}  +12.15d {+12d 09' 02"}
MOON_DIST:       147.47 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.39, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.51, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:27:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.116d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 40"} (J2000)
POINT_ROLL:      282.097d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69649.35 SOD {19:20:49.35} UT,   134.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.605
N_STARS:         190
X_OFFSET:        341 [pixels]
Y_OFFSET:        500 [pixels]
X_MAX:           1300 [pixels]
Y_MAX:           1459 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00531223000msufc0134.fits
SUN_POSTN:       146.62d {+09h 46m 28s}  +13.42d {+13d 24' 58"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.88d {+08h 59m 32s}  +12.15d {+12d 08' 53"}
MOON_DIST:       147.46 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.39, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.51, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:28:18 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.116d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 40"} (J2000)
ROLL:            282.097d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69649.35 SOD {19:20:49.35} UT,   134.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     366837658
X_OFFSET:        660 [pixels]
Y_OFFSET:        819 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       820
Y_GRB_POS:       979
BINNING_INDEX:   1
IM_URL:          sw00531223000msuni0144.fits
SUN_POSTN:       146.62d {+09h 46m 28s}  +13.42d {+13d 24' 57"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.89d {+08h 59m 34s}  +12.15d {+12d 08' 43"}
MOON_DIST:       147.45 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.39, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.51, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:28:30 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.116d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 40"} (J2000)
ROLL:            282.097d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69649.35 SOD {19:20:49.35} UT,   134.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     366837658
X_OFFSET:        660 [pixels]
Y_OFFSET:        819 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       820
Y_GRB_POS:       979
BINNING_INDEX:   1
IM_URL:          sw00531223000msuni0144.fits
SUN_POSTN:       146.62d {+09h 46m 28s}  +13.42d {+13d 24' 57"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.89d {+08h 59m 34s}  +12.14d {+12d 08' 41"}
MOON_DIST:       147.45 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.39, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.51, 15.95 [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 #13654
K. L. Page (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), S. T. Holland (STScI), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 19:18:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120816A (trigger=531223). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 282.126, -6.979, which is
```
   RA(J2000) = 18h 48m 30s
   Dec(J2000) = -06d 58' 43"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak with a duration of about 5 sec. The peak count rate was ~800 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 19:20:47.3 UT, 132.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 282.14430, -6.93753 which is equivalent to:
```
   RA(J2000)  = 18h 48m 34.63s
   Dec(J2000) = -06d 56' 15.1"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 162 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (3.73 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 4.4 (+3.28/-2.78) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 134 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 0.00% 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 K. L. Page (kpa AT star.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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:34:09 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
POINT_ROLL:      282.099d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69807.45 SOD {19:23:27.45} UT,   292.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.651
N_STARS:         190
X_OFFSET:        101 [pixels]
Y_OFFSET:        260 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1699 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00531223000msufc0292.fits
SUN_POSTN:       146.62d {+09h 46m 29s}  +13.41d {+13d 24' 53"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.94d {+08h 59m 46s}  +12.13d {+12d 07' 43"}
MOON_DIST:       147.40 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:34:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
POINT_ROLL:      282.099d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69807.45 SOD {19:23:27.45} UT,   292.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.651
N_STARS:         190
X_OFFSET:        101 [pixels]
Y_OFFSET:        260 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1699 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00531223000msufc0292.fits
SUN_POSTN:       146.62d {+09h 46m 29s}  +13.41d {+13d 24' 52"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.95d {+08h 59m 48s}  +12.13d {+12d 07' 38"}
MOON_DIST:       147.40 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:34:55 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     531223,   Seg_Num: 0
GRB_RA:          282.1428d {+18h 48m 34.27s} (J2000),
                 282.3129d {+18h 49m 15.09s} (current),
                 281.4690d {+18h 45m 52.55s} (1950)
GRB_DEC:          -6.9382d {-06d 56' 17.5"} (J2000),
                  -6.9233d {-06d 55' 23.9"} (current),
                  -6.9952d {-06d 59' 42.5"} (1950)
GRB_ERROR:       2.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69667.00 SOD {19:21:07.00} UT,   152.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       146.62d {+09h 46m 29s}  +13.41d {+13d 24' 52"}
SUN_DIST:        135.97 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.95d {+08h 59m 48s}  +12.13d {+12d 07' 36"}
MOON_DIST:       147.42 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.43, -2.52 [deg] galactic lon,lat of the burst
ECL_COORDS:      282.54, 15.97 [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:     Thu 16 Aug 12 19:35:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
ROLL:            282.099d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69807.45 SOD {19:23:27.45} UT,   292.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     366837817
X_OFFSET:        660 [pixels]
Y_OFFSET:        819 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       820
Y_GRB_POS:       979
BINNING_INDEX:   1
IM_URL:          sw00531223000msuni0302.fits
SUN_POSTN:       146.62d {+09h 46m 30s}  +13.41d {+13d 24' 52"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.96d {+08h 59m 49s}  +12.12d {+12d 07' 30"}
MOON_DIST:       147.39 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:35:37 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
ROLL:            282.099d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  69807.45 SOD {19:23:27.45} UT,   292.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     366837817
X_OFFSET:        660 [pixels]
Y_OFFSET:        819 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       820
Y_GRB_POS:       979
BINNING_INDEX:   1
IM_URL:          sw00531223000msuni0302.fits
SUN_POSTN:       146.62d {+09h 46m 30s}  +13.41d {+13d 24' 51"}
SUN_DIST:        135.95 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.96d {+08h 59m 50s}  +12.12d {+12d 07' 28"}
MOON_DIST:       147.39 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:39:38 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
POINT_ROLL:      282.098d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  70386.09 SOD {19:33:06.09} UT,   871.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.717
N_STARS:         190
X_OFFSET:        101 [pixels]
Y_OFFSET:        260 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1699 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00531223000msufc0871.fits
SUN_POSTN:       146.63d {+09h 46m 30s}  +13.41d {+13d 24' 48"}
SUN_DIST:        135.94 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      134.99d {+08h 59m 58s}  +12.11d {+12d 06' 48"}
MOON_DIST:       147.36 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:40:11 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
POINT_ROLL:      282.098d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  70386.09 SOD {19:33:06.09} UT,   871.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.717
N_STARS:         190
X_OFFSET:        101 [pixels]
Y_OFFSET:        260 [pixels]
X_MAX:           1540 [pixels]
Y_MAX:           1699 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw00531223000msufc0871.fits
SUN_POSTN:       146.63d {+09h 46m 30s}  +13.41d {+13d 24' 48"}
SUN_DIST:        135.94 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      135.00d {+08h 59m 59s}  +12.11d {+12d 06' 42"}
MOON_DIST:       147.35 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:41:26 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
ROLL:            282.098d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  70386.09 SOD {19:33:06.09} UT,   871.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     366838395
X_OFFSET:        660 [pixels]
Y_OFFSET:        819 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       820
Y_GRB_POS:       979
BINNING_INDEX:   1
IM_URL:          sw00531223000msuni0881.fits
SUN_POSTN:       146.63d {+09h 46m 30s}  +13.41d {+13d 24' 47"}
SUN_DIST:        135.94 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      135.01d {+09h 00m 02s}  +12.11d {+12d 06' 29"}
MOON_DIST:       147.34 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 16 Aug 12 19:41:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     531223,   Seg_Num: 0
POINT_RA:        282.117d {+18h 48m 28s} (J2000)
POINT_DEC:        -6.961d {-06d 57' 39"} (J2000)
ROLL:            282.098d
IMG_START_DATE:  16155 TJD;   229 DOY;   12/08/16
IMG_START_TIME:  70386.09 SOD {19:33:06.09} UT,   871.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     366838395
X_OFFSET:        660 [pixels]
Y_OFFSET:        819 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       820
Y_GRB_POS:       979
BINNING_INDEX:   1
IM_URL:          sw00531223000msuni0881.fits
SUN_POSTN:       146.63d {+09h 46m 31s}  +13.41d {+13d 24' 47"}
SUN_DIST:        135.94 [deg]   Sun_angle= -9.0 [hr] (East of Sun)
MOON_POSTN:      135.01d {+09h 00m 03s}  +12.11d {+12d 06' 26"}
MOON_DIST:       147.34 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:       26.40, -2.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      282.52, 15.95 [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 #13655
W. Zheng (U Mich), W. Rujopakarn (Steward), T. Guver (Sabanci University), report on behalf of the ROTSE collaboration:
ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe, Turkey, automatically responded to GRB 120816A (Swift trigger 531223; Page et al., GCN 13654). An automated response took the first image at 19:23:18.6 UT, 285 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 50 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going.
Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle or the XRT error circle; however, we are limited as the field is severely crowded. Individual images have limiting magnitudes ranging from 13.9-15.1; we set the following specific limits.
```
start UT end UT t_exp(s) mlim Coadd?
----------------------------------------------------
19:23:18.6   19:23:23.6         5     13.9      N
19:23:45.6   19:23:50.6         5     14.2      N
19:24:13.1   19:24:18.1         5     14.3      N
19:25:34.5   19:25:54.5        20     14.8      N
19:35:05.4   19:40:22.7       600     15.1      Y
```
GCN Circular #13656
Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 120816A detected by SWIFT (trigger 531223) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
The observations started 526s after the GRB trigger (delay due to the beginning of the night). The elevation of the field increased from 36 degrees above horizon and weather conditions were good.
We co-added a series of exposures but we do not detect any OT at the XRT position (Page et al. GCNC 13654):
From t0+526s to t0+942s, R > 16.5
Galactic coordinates are lon= 26.384d lat= -2.527d and the galactic extinction in R band is about 3 magnitudes (estimated from D. Schlegel et al. 1998ApJ...500..525S). Although the field is very dense, there are no star brighter than 18th mag in the XRT error box.
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
This message may be cited.
GCN Circular #13657
Arne Rau and Gottfried Kanbach (both MPE Garching) report on behalf of the OPTIMA-Burst Team:
"We observed the location of GRB 120816A (Page et al. GCN #13654) with OPTIMA-Burst (Kanbach et al. 2008, Astrophys. and Sp. Sci. Lib. Vol. 351, 153) currently mounted at the 1.3m telescope at Skinakas Observatory, University of Crete. Observations started at 19:22:44 UT (249 sec after the burst) with unfiltered 20s exposures using the field-viewing CCD camera. Within the updated XRT error circle we find a fading source located at:
```
RA(J2000) = 18:48:34.4
Dec(J2000) = -06:56:16
```
with an approximate uncertainty of 1" in both coordinates.
We measure the following magnitudes:
```
T0+         white
-----------------
249s        ~17.8
4844s       >19.1
```
calibrated against the R=15.2mag reference star USNO-B1.0 0830-0537586."
GCN Circular #13658
M. Jel=EDnek, J. C. Tello, J. Gorosabel and A. J. Castro-Tirado (IAA-CSIC Granada), on behalf of a larger collaboration, report:
"Following the detection of GRB 120816A (Page et al. GCNC 13654), the BOOTES-2/TELMA 0.6m telescope (+COLORES) in southern Spain started to observe the field about one hour after the GRB, as soon as the night started, obtaining a series of unfiltered images. In particular, a combination of 15x60s frames gathered around 20:24:35UT (i.e. T0+66min) provides a limit of R > 18 at the position of the reported optical counterpart (Rau and Kanbach GCNC 13657)."
This message can be quoted.
GCN Circular #13659
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), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-60 to T+192 sec from the recent telemetry downlink, we report further analysis of BAT GRB 120816A (trigger #531223) (Page, et al., GCN Circ. 13654). The BAT ground-calculated position is RA, Dec = 282.133, -6.981 deg, which is
```
   RA(J2000)  =  18h 48m 32.0s 
   Dec(J2000) = -06d 58' 51.6" 
```
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%.
The mask-weighted light curve shows a single peak starting at ~T+0 sec, peaking at ~T+1 sec, and ending at ~T+8 sec. T90 (15-350 keV) is 7.6 +- 3.1 sec (estimated error including systematics).
The time-averaged spectrum from T-1.97 to T+6.66 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.54 +- 0.40. The fluence in the 15-150 keV band is 4.3 +- 1.0 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.82 sec in the 15-150 keV band is 2.1 +- 0.5 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/531223/BA/
GCN Circular #13660
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 2433 s of XRT Photon Counting mode data and 4 UVOT images for GRB 120816A, 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 = 282.14298, -6.93791 which is equivalent to:
```
RA (J2000): 18h 48m 34.31s
Dec (J2000): -06d 56' 16.5"
```
with an uncertainty of 1.7 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 #13663
K. L. Page (U Leicester) reports on behalf of the Swift-XRT team:
We have analysed 5.6 ks of XRT data for GRB 120816A (Page et al. GCN Circ. 13654), from 136 s to 12.5 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 13660).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.94 (+0.08, -0.07).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.10 (+0.26, -0.25). The best-fitting absorption column is 6.4 (+1.5, -1.4) x 10^21 cm^-2, in excess of the Galactic value of 3.7 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 4.8 x 10^-11 (9.5 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     6.4 (+1.5, -1.4) x 10^21 cm^-2
Galactic foreground: 3.7 x 10^21 cm^-2
Excess significance: 3.2 sigma
Photon index:	     2.10 (+0.26, -0.25)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00531223.
This circular is an official product of the Swift-XRT team.
GCN Circular #13665
U.Quadri, L.Strabla and R.Girelli A.Quadri report:
We imaged the field of GRB 120816A detected by SWIFT(trigger 531223) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy.
The observations started 26.7 min. after the GRB trigger,with our schmidt telescope D=320 mm F/D=3.1.
Weather conditions were discrete.
We co-added 4 series of 30 x 120s exposures.
We did not appear any optical counterpart in the error box of the XRTcandidate (Page et al.GCNC 13654).
```
Start       End       Vlim
27.6min     278min    17.7
```
Magnitudes were estimated with the USNO-B1 cat.
The message may be cited.
GCN Circular #13668
A. Ivanov, V. Ivanov, V. Lysenko (Kuban State University), A. Pozanenko (IKI)
We observed the field of the Swift GRB 120816A (Page et al., GCN 13654) with 20-inch telescope of Kuban State University Astrophysical Observatory on August 16 starting on (UT) 19:34:49. We took several series of 40 s and 60 s exposures using R filter. In a stacked image we do not detect any new source in the enhanced XRT error circle (Osborne et al., GCN 13660), in particular we do not detect the OT candidate (Rau et al., GCN 13657). A preliminary photometry is based on the nearby USNO-B1.0 (R2) stars:
```
 Start,         T0+         Filter, Exposure,    OT,   uplim (3 sigma)
  (UT)         (mid, d)             (s)
19:34:49   0.0115      R       40               n/d    16.0
19:36:01   0.0221      R     830               n/d    17.9
19:36:01   0.0539      R   3530               n/d    18.1
```
GCN Circular #13678
S. Immler (NASA/CRESST/GSFC) and K. L. Page (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 120815A starting 117 s after the BAT trigger (Page et al., 2012, GCNC 13654). We detect an uncatalogued source inside the enhanced XRT error circle (Osborne et al., 2012, GCNC 13660) with preliminary coordinates
```
   RA (J2000.0) = 18:48:34.5 = 282.14359 (deg)
  Dec (J2000.0) = -06:56:16.4 = -6.93788 (deg)
```
and an estimated uncertainty of 0.6 arcsec (radius, 90% confidence, statistical + systematic). The UVOT detection is consistent with the optical afterglow reported by Rau et al. (2012, GCNC 13657). Source magnitudes and 3-sigma upper limits at this location are given below (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373).
```
Filter       TSTART   TSTOP    Exp Time      Mag  Err
-----------------------------------------------------
white          134      284         147      18.5  0.2
white          573     6306         598      19.9  0.2
    v          117     6716         500     >19.0
    b          548    11345        1174     >19.6
    u          293     7286         672     >21.1
 uvw1          672     7126         490     >21.1
 uvm2          647     6921         490     >19.5
 uvw2          599     6511         490     >19.8
-----------------------------------------------------
```
The quoted magnitudes and upper limits have not been corrected for the Galactic extinction along the line of sight to this burst of E_{B-V} = 0.703 mag.
GCN Report 381.1
GCN_Report 381.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_381_1.pdf by K.L. Page at U. Leicester titled: "Swift Observations of GRB 120816A"

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Jochen Greiner, last update: 22-Aug-2012 [Disclaimer]