Gamma-ray Burst 100508A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:21:59 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     421386,   Seg_Num: 0
GRB_RA:           76.250d {+05h 05m 00s} (J2000),
                  76.361d {+05h 05m 27s} (current),
                  75.712d {+05h 02m 51s} (1950)
GRB_DEC:         -20.721d {-20d 43' 14"} (J2000),
                 -20.707d {-20d 42' 25"} (current),
                 -20.788d {-20d 47' 17"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1447 [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:        15324 TJD;   128 DOY;   10/05/08
GRB_TIME:        33642.22 SOD {09:20:42.22} UT
GRB_PHI:          -4.78 [deg]
GRB_THETA:        34.13 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.47 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -2  +0  +0 -66  +0 
SUN_POSTN:        45.22d {+03h 00m 53s}  +17.11d {+17d 06' 18"}
SUN_DIST:         48.61 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.45d {+22h 45m 49s}   -3.21d {-03d 12' 18"}
MOON_DIST:        93.45 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.36,-32.29 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       72.21,-43.31 [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 = 65.05,-17.00 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:23:22 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.245d {+05h 04m 59s} (J2000)
POINT_DEC:       -20.704d {-20d 42' 14"} (J2000)
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33789.74 SOD {09:23:09.74} UT,   147.5 [sec] since BAT Trigger Time
COUNTS:          10    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:     Sat 08 May 10 09:24:53 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     421386,   Seg_Num: 0
GRB_RA:           76.250d {+05h 05m 00s} (J2000),
                  76.361d {+05h 05m 27s} (current),
                  75.712d {+05h 02m 51s} (1950)
GRB_DEC:         -20.721d {-20d 43' 14"} (J2000),
                 -20.707d {-20d 42' 25"} (current),
                 -20.788d {-20d 47' 17"} (1950)
GRB_DATE:        15324 TJD;   128 DOY;   10/05/08
GRB_TIME:        33642.22 SOD {09:20:42.22} UT
TRIGGER_INDEX:   20000
GRB_PHI:          -4.78 [deg]
GRB_THETA:        34.13 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.47 [sigma]
LC_URL:          sw00421386000msb.lc
SUN_POSTN:        45.22d {+03h 00m 54s}  +17.11d {+17d 06' 20"}
SUN_DIST:         48.61 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.47d {+22h 45m 54s}   -3.20d {-03d 11' 42"}
MOON_DIST:        93.43 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.36,-32.29 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       72.21,-43.31 [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 = 65.05,-17.00 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:26:03 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.245d {+05h 04m 59s} (J2000)
POINT_DEC:       -20.704d {-20d 42' 14"} (J2000)
POINT_ROLL:      318.904d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33794.07 SOD {09:23:14.07} UT,   151.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.983
N_STARS:         35
X_OFFSET:        355 [pixels]
Y_OFFSET:        579 [pixels]
X_MAX:           1314 [pixels]
Y_MAX:           1538 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00421386000msufc0151.fits
SUN_POSTN:        45.23d {+03h 00m 54s}  +17.11d {+17d 06' 21"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.48d {+22h 45m 56s}   -3.19d {-03d 11' 27"}
MOON_DIST:        93.42 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.21,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:26:03 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.245d {+05h 04m 59s} (J2000)
POINT_DEC:       -20.704d {-20d 42' 14"} (J2000)
POINT_ROLL:      318.904d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33794.07 SOD {09:23:14.07} UT,   151.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.983
N_STARS:         35
X_OFFSET:        355 [pixels]
Y_OFFSET:        579 [pixels]
X_MAX:           1314 [pixels]
Y_MAX:           1538 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00421386000msufc0151.fits
SUN_POSTN:        45.23d {+03h 00m 54s}  +17.11d {+17d 06' 21"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.48d {+22h 45m 56s}   -3.19d {-03d 11' 27"}
MOON_DIST:        93.42 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.21,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:26:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.245d {+05h 04m 59s} (J2000)
POINT_DEC:       -20.704d {-20d 42' 14"} (J2000)
POINT_ROLL:      318.904d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33794.07 SOD {09:23:14.07} UT,   151.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.983
N_STARS:         35
X_OFFSET:        355 [pixels]
Y_OFFSET:        579 [pixels]
X_MAX:           1314 [pixels]
Y_MAX:           1538 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00421386000msufc0151.fits
SUN_POSTN:        45.23d {+03h 00m 54s}  +17.11d {+17d 06' 21"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.48d {+22h 45m 56s}   -3.19d {-03d 11' 25"}
MOON_DIST:        93.42 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.21,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_field_srclist.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:27:15 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     421386,   Seg_Num: 0
GRB_RA:           76.2464d {+05h 04m 59.13s} (J2000),
                  76.3578d {+05h 05m 25.88s} (current),
                  75.7082d {+05h 02m 49.96s} (1950)
GRB_DEC:         -20.7116d {-20d 42' 41.7"} (J2000),
                 -20.6980d {-20d 41' 52.6"} (current),
                 -20.7791d {-20d 46' 44.6"} (1950)
GRB_ERROR:       3.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33820.00 SOD {09:23:40.00} UT,   177.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        45.23d {+03h 00m 54s}  +17.11d {+17d 06' 22"}
SUN_DIST:         48.60 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.49d {+22h 45m 58s}   -3.19d {-03d 11' 12"}
MOON_DIST:        93.42 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.35,-32.29 [deg] galactic lon,lat of the burst
ECL_COORDS:       72.21,-43.31 [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:     Sat 08 May 10 09:27:37 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.245d {+05h 04m 59s} (J2000)
POINT_DEC:       -20.704d {-20d 42' 14"} (J2000)
ROLL:            318.904d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33794.07 SOD {09:23:14.07} UT,   151.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     295003399
X_OFFSET:        674 [pixels]
Y_OFFSET:        898 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1058
BINNING_INDEX:   1
IM_URL:          sw00421386000msuni0157.fits
SUN_POSTN:        45.23d {+03h 00m 54s}  +17.11d {+17d 06' 22"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.49d {+22h 45m 59s}   -3.19d {-03d 11' 08"}
MOON_DIST:        93.41 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.21,-43.30 [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:     Sat 08 May 10 09:27:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.245d {+05h 04m 59s} (J2000)
POINT_DEC:       -20.704d {-20d 42' 14"} (J2000)
ROLL:            318.904d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33794.07 SOD {09:23:14.07} UT,   151.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     295003399
X_OFFSET:        674 [pixels]
Y_OFFSET:        898 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1058
BINNING_INDEX:   1
IM_URL:          sw00421386000msuni0157.fits
SUN_POSTN:        45.23d {+03h 00m 54s}  +17.11d {+17d 06' 22"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.49d {+22h 45m 59s}   -3.19d {-03d 11' 08"}
MOON_DIST:        93.41 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.21,-43.30 [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_field_image.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:33:34 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
POINT_ROLL:      318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33952.71 SOD {09:25:52.71} UT,   310.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.740
N_STARS:         56
X_OFFSET:        115 [pixels]
Y_OFFSET:        339 [pixels]
X_MAX:           1554 [pixels]
Y_MAX:           1778 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00421386000msufc0310.fits
SUN_POSTN:        45.23d {+03h 00m 55s}  +17.11d {+17d 06' 26"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.54d {+22h 46m 09s}   -3.16d {-03d 09' 53"}
MOON_DIST:        93.38 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:33:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
POINT_ROLL:      318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33952.71 SOD {09:25:52.71} UT,   310.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.740
N_STARS:         56
X_OFFSET:        115 [pixels]
Y_OFFSET:        339 [pixels]
X_MAX:           1554 [pixels]
Y_MAX:           1778 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00421386000msufc0310.fits
SUN_POSTN:        45.23d {+03h 00m 55s}  +17.11d {+17d 06' 26"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.54d {+22h 46m 10s}   -3.16d {-03d 09' 50"}
MOON_DIST:        93.38 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_field_srclist.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:33:34 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
POINT_ROLL:      318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33952.71 SOD {09:25:52.71} UT,   310.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.740
N_STARS:         56
X_OFFSET:        115 [pixels]
Y_OFFSET:        339 [pixels]
X_MAX:           1554 [pixels]
Y_MAX:           1778 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00421386000msufc0310.fits
SUN_POSTN:        45.23d {+03h 00m 55s}  +17.11d {+17d 06' 26"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.54d {+22h 46m 09s}   -3.16d {-03d 09' 53"}
MOON_DIST:        93.38 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:34:56 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
ROLL:            318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33952.71 SOD {09:25:52.71} UT,   310.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     295003558
X_OFFSET:        674 [pixels]
Y_OFFSET:        898 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1058
BINNING_INDEX:   1
IM_URL:          sw00421386000msuni0316.fits
SUN_POSTN:        45.23d {+03h 00m 55s}  +17.11d {+17d 06' 27"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.55d {+22h 46m 12s}   -3.16d {-03d 09' 36"}
MOON_DIST:        93.37 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [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:     Sat 08 May 10 09:35:05 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
ROLL:            318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33952.71 SOD {09:25:52.71} UT,   310.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     295003558
X_OFFSET:        674 [pixels]
Y_OFFSET:        898 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1058
BINNING_INDEX:   1
IM_URL:          sw00421386000msuni0316.fits
SUN_POSTN:        45.23d {+03h 00m 56s}  +17.11d {+17d 06' 27"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.55d {+22h 46m 12s}   -3.16d {-03d 09' 34"}
MOON_DIST:        93.37 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [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_field_image.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:35:14 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     421386,   Seg_Num: 0
GRB_RA:           76.2455d {+05h 04m 58.92s} (J2000),
                  76.3569d {+05h 05m 25.66s} (current),
                  75.7073d {+05h 02m 49.74s} (1950)
GRB_DEC:         -20.7114d {-20d 42' 41.0"} (J2000),
                 -20.6978d {-20d 41' 51.9"} (current),
                 -20.7789d {-20d 46' 43.9"} (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:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33820.00 SOD {09:23:40.00} UT,   177.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        45.23d {+03h 00m 56s}  +17.11d {+17d 06' 27"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.55d {+22h 46m 12s}   -3.16d {-03d 09' 32"}
MOON_DIST:        93.37 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.35,-32.29 [deg] galactic lon,lat of the burst
ECL_COORDS:       72.21,-43.30 [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:     Sat 08 May 10 09:39:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
POINT_ROLL:      318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  34506.26 SOD {09:35:06.26} UT,   864.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.647
N_STARS:         78
X_OFFSET:        115 [pixels]
Y_OFFSET:        339 [pixels]
X_MAX:           1554 [pixels]
Y_MAX:           1778 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00421386000msufc0864.fits
SUN_POSTN:        45.23d {+03h 00m 56s}  +17.11d {+17d 06' 30"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.59d {+22h 46m 21s}   -3.14d {-03d 08' 35"}
MOON_DIST:        93.34 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:40:03 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
POINT_ROLL:      318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  34506.26 SOD {09:35:06.26} UT,   864.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.647
N_STARS:         78
X_OFFSET:        115 [pixels]
Y_OFFSET:        339 [pixels]
X_MAX:           1554 [pixels]
Y_MAX:           1778 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00421386000msufc0864.fits
SUN_POSTN:        45.23d {+03h 00m 56s}  +17.11d {+17d 06' 31"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.59d {+22h 46m 21s}   -3.14d {-03d 08' 31"}
MOON_DIST:        93.34 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_field_srclist.ps.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:39:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
POINT_ROLL:      318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  34506.26 SOD {09:35:06.26} UT,   864.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.647
N_STARS:         78
X_OFFSET:        115 [pixels]
Y_OFFSET:        339 [pixels]
X_MAX:           1554 [pixels]
Y_MAX:           1778 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00421386000msufc0864.fits
SUN_POSTN:        45.23d {+03h 00m 56s}  +17.11d {+17d 06' 30"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.59d {+22h 46m 21s}   -3.14d {-03d 08' 35"}
MOON_DIST:        93.34 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 09:41:31 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
ROLL:            318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  34506.26 SOD {09:35:06.26} UT,   864.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     295004112
X_OFFSET:        674 [pixels]
Y_OFFSET:        898 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1058
BINNING_INDEX:   1
IM_URL:          sw00421386000msuni0870.fits
SUN_POSTN:        45.24d {+03h 00m 57s}  +17.11d {+17d 06' 32"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.60d {+22h 46m 24s}   -3.14d {-03d 08' 13"}
MOON_DIST:        93.33 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [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:     Sat 08 May 10 09:41:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     421386,   Seg_Num: 0
POINT_RA:         76.243d {+05h 04m 58s} (J2000)
POINT_DEC:       -20.705d {-20d 42' 18"} (J2000)
ROLL:            318.905d
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  34506.26 SOD {09:35:06.26} UT,   864.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     295004112
X_OFFSET:        674 [pixels]
Y_OFFSET:        898 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1058
BINNING_INDEX:   1
IM_URL:          sw00421386000msuni0870.fits
SUN_POSTN:        45.24d {+03h 00m 57s}  +17.11d {+17d 06' 32"}
SUN_DIST:         48.59 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      341.60d {+22h 46m 24s}   -3.14d {-03d 08' 11"}
MOON_DIST:        93.33 [deg]
MOON_ILLUM:      30 [%]
GAL_COORDS:      221.34,-32.29 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       72.20,-43.30 [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_field_image.ps.gz file does not exist; skipping the attachment.

GCN Circular #10728
R. Margutti (INAF-OAB), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), S. Campana (INAF-OAB), A. de Ugarte Postigo (INAF-OAB), P. A. Evans (U Leicester), J. M. Gelbord (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA), G. Tagliaferri (INAF-OAB) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:
At 09:20:42 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100508A (trigger=421386). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 76.250, -20.721 which is
```
   RA(J2000) = 05h 05m 00s
   Dec(J2000) = -20d 43' 14"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual for an image trigger, the BAT light curve shows nothing of note.
The XRT began observing the field at 09:23:09.7 UT, 147.5 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 76.2456, -20.7114 which is equivalent to:
```
   RA(J2000)  = 05h 04m 58.95s
   Dec(J2000) = -20d 42' 41.1"
```
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 37 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 (2.37e+20 cm^-2, Kalberla et al. 2005), with an excess column of 2.3 (+2.14/-1.86) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 151 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 BAT 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 0.03. There is a possible uncataloged object within the XRT error circle, but due to analysis complications we cannot confirm the validity.
Burst Advocate for this burst is R. Margutti (raffaella.margutti AT brera.inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #10729
B. E. Schaefer (Louisiana State), L. Xiao (Louisiana State), S. B. Pandey (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB 100508A (Swift trigger 421386; Margutti et al., GCN 10728), producing images beginning 156.8 s after the GCN notice time. An automated response took the first image at 09:23:19.1 UT, 156.8 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 10 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; the field is not crowded. Individual images have limiting magnitudes ranging from 16.3-16.6; we set the following specific limits.
```
start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
09:25:55.9   09:26:15.9        20     16.5          156.8       N
```
GCN Circular #10730
W.B. Landsman (GSFC) and R. Margutti (INAF-OAB) report on behalf of the Swift/UVOT team.
Swift/UVOT began settled observations of the field of GRB 100508A starting 152 s after the BAT trigger (Margutti et al. GCN Circ. 10728). An uncatalogued fading source is seen in the 2.7' x 2.7' rapidly available subimage within the XRT error circle at
```
     RA(J2000) = 05h 04m 58.99s
     Dec(J2000) = -20d 42' 41.1"
```
with an uncertainty of about 0.6 arc sec (radius, 90% containment), The initial estimated magnitudes are as follows:
```
Filter   T_start    Exp(s)      Mag  Err
----------------------------------------------
white       152       150     18.87  0.09
u           310       250     19.25  0.20
white       864       150     20.7   0.44
----------------------------------------------
```
The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.87 (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 08 May 10 12:29:57 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     421386,   Seg_Num: 0
GRB_RA:           76.2466d {+05h 04m 59.18s} (J2000),
                  76.3580d {+05h 05m 25.92s} (current),
                  75.7084d {+05h 02m 50.01s} (1950)
GRB_DEC:         -20.7113d {-20d 42' 40.6"} (J2000),
                 -20.6977d {-20d 41' 51.5"} (current),
                 -20.7788d {-20d 46' 43.5"} (1950)
GRB_ERROR:       0.6 [arcsec radius, statistical only]
GRB_MAG:         18.89 +/- 0.10 [mag]
FILTER:          10, White
IMG_START_DATE:  15324 TJD;   128 DOY;   10/05/08
IMG_START_TIME:  33800.00 SOD {09:23:20.00} UT,   157.8 [sec] since BAT Trigger Time
SUN_POSTN:        45.35d {+03h 01m 24s}  +17.14d {+17d 08' 26"}
SUN_DIST:         48.55 [deg]   Sun_angle= -2.1 [hr] (East of Sun)
MOON_POSTN:      342.87d {+22h 51m 29s}   -2.55d {-02d 32' 52"}
MOON_DIST:        92.36 [deg]
MOON_ILLUM:      29 [%]
GAL_COORDS:      221.35,-32.29 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       72.21,-43.30 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN Circular #10731
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 1306 s of XRT Photon Counting mode data and 2 UVOT images for GRB 100508A, 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 = 76.24555, -20.71171 which is equivalent to:
```
RA (J2000): 05h 04m 58.93s
Dec (J2000): -20d 42' 42.2"
```
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 #10732
M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), R. Margutti (INAF-OAB), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), 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 100508A (trigger #421386) (Margutti, et al., GCN Circ. 10728). The BAT ground-calculated position is RA, Dec = 76.263, -20.744 deg, which is
```
   RA(J2000)  =  05h 05m 03.1s 
   Dec(J2000) = -20d 44' 36.8" 
```
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 70%.
The mask-weighted light curve shows a broad peak starting at ~T-25 sec and ending around T+200 sec with a very weak tail out to around T+400 sec. T90 (15-350 keV) is 52 +- 10 sec (estimated error including systematics).
The time-averaged spectrum from T-8 to T+59 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.23 +- 0.25. The fluence in the 15-150 keV band is 7.0 +- 1.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+6.04 sec in the 15-150 keV band is 0.4 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. One small caveate: the fluence and peak flux should be taken as lower limits given that there are three 2-3 sec gaps (between 7 and 20 sec) in the event-by-event data received on the ground.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/421386/BA/
GCN Circular #10733
R. Margutti, B. Sbarufatti, A. de Ugarte Postigo (INAF-OAB) report on behalf of the Swift-XRT team:
We have analysed 3.0 ks of XRT data for GRB 100508A (Margutti et al. GCN Circ. 10728), from 132 s to 7.3 ks after the BAT trigger. The data comprise 40 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The UVOT-enhanced XRT position was given by Beardmore al. in GCN Circ. 10731.
The light curve can be modelled with an initial power-law decay with an index of alpha=1.49 (+0.22, -0.18), followed by a break at T+694 s to an alpha=0.39 (+0.08, -0.09).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.66 (+0.28, -0.27). The best-fitting absorption column is 1.4 (+0.9, -0.7) x 10^21 cm^-2, in excess of the Galactic value of 2.4 x 10^20 cm^-2 (Kalberla et al. 2005). Uncertainties are given at 90% c.l. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.7 x 10^-11 (5.7 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 0.39, the count rate at T+24 hours will be 0.068 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.2 x 10^-12 (3.9 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00421386.
This circular is an official product of the Swift-XRT team.
GCN Circular #10734
P. Schady, F. Olivares, (MPE Garching), A. Rossi (Tautenburg Obs.) and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 100508A (Swift trigger 421386; Margutti et al., GCN #10728) 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 22:50 UT on date, 13.5 hrs after the GRB trigger, and were performed in poor seeing conditions and high airmass.
We detect an extended source in all four optical filters within the 1.7 Swift-XRT refined error circle reported by Beardmore et al. (GCN #10731), and at a position consistent with the UVOT position reported by Landsman et al. (GCN #10730).
Based on 15.3 min of total exposures in g'r'i'z' and 16 min in JHK, we estimate preliminary magnitudes and upper limits in the optical and IR respectively (all in AB system) of
```
g' = 22.0 +- 0.1 mag
r' = 21.8 +- 0.1 mag
i' = 21.5 +- 0.1 mag
z' = 21.7 +- 0.2 mag
J > 21.4
H > 20.8
K > 20.1
```
at the UVOT position using aperture photometry.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.029 in the direction of the burst (Schlegel et al. 1998). No correction has been applied to the optical magnitudes for the possible contribution from the underlying host galaxy.
GCN Circular #10736
W.B. Landsman (GSFC) and R. Margutti (INAF-OAB) report on behalf of=20 the Swift/UVOT team.
Swift/UVOT has continued observations of GRB100508A through 93,000s=20 after the initial trigger (Margutti et al. GCN 10728). The afterglow=20 reported by Landsman and Margutti (GCN 10730) was not detected in any=20 filter past 12,000s after the initial trigger. Magnitudes and 3=20 sigma upper limits for selected exposures are reported below:
```
FILTER     T_start(s)     Exposure     Mag/3UL
white fc     152            147        18.91 =B1 0.07
white        864            147        20.70 =B1 0.31
white      11708            295        21.22 =B1 0.30
u            310            246        19.16 =B1 0.15
u           6860            197        20.12 =B1 0.36
b           5634            197 > 20.7
v           6250            197 > 19.7
```
At late times our 3" photometry aperture includes the galaxy reported=20 by Schady et al. (GCN 10734), which may be the GRB host. This galaxy=20 is also listed in the SuperCosmos Sky Survey (=20 http://www-wfau.roe.ac.uk/sss/docs.html ) with coordinates 2.1" distant=20 from the UVOT position. The late-time white magnitude in a 6491s=20 summed exposure taken between 57097s and 93249s after the trigger within=20 the 3" aperture used to measure the afterglow is 21.86 =B1 0.12.
There are no detections or interesting magnitude limits in the UV filters.
The above magnitudes are not corrected for the Galactic extinction=20 corresponding to a reddening of E(B-V) =3D 0.029 (Schlegel et al., 1998,=20 ApJS, 500, 525). There was a typo in the value of E(B-V) reported for=20 this burst by Landsman & Margutti (GCN 10730). The photometry is on=20 the UVOT photometric system described in Poole et al. (2008, MNRAS,=20 383, 627).
GCN Report 282.1
GCN_Report 282.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_282_1.pdf by M. Margutti at INAF-OAB titled: "Final report on Swift Observations of GRB 100508A"
arXiv:1505.06743 X-shooter redshift: 0.5201

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Jochen Greiner, last update: 25-Jun-2015 [Disclaimer]