Gamma-ray Burst 080426

(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 26 Apr 08 13:23:35 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     310219,   Seg_Num: 0
GRB_RA:           26.574d {+01h 46m 18s} (J2000),
                  26.736d {+01h 46m 57s} (current),
                  25.608d {+01h 42m 26s} (1950)
GRB_DEC:         +69.492d {+69d 29' 30"} (J2000),
                 +69.533d {+69d 31' 59"} (current),
                 +69.242d {+69d 14' 30"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       597 [cnts]    Image_Peak=69 [image_cnts]
TRIGGER_DUR:     0.064 [sec] 
TRIGGER_INDEX:   10411     E_range: 15-50 keV
BKG_INTEN:       32409 [cnts]
BKG_TIME:        48189.25 SOD {13:23:09.25} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14582 TJD;   117 DOY;   08/04/26
GRB_TIME:        48202.69 SOD {13:23:22.69} UT
GRB_PHI:         -98.79 [deg]
GRB_THETA:        29.67 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     25.25 [sigma]
IMAGE_SIGNIF:    8.32 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +1 +17  +0  +1 -55  +1 
SUN_POSTN:        34.34d {+02h 17m 23s}  +13.74d {+13d 44' 38"}
SUN_DIST:         56.00 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.15d {+19h 00m 37s}  -26.03d {-26d 01' 38"}
MOON_DIST:       118.31 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.73,  7.13 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       58.75, 52.84 [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 = 185.68,17.84 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:27:05 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     310219,   Seg_Num: 0
GRB_RA:           26.574d {+01h 46m 18s} (J2000),
                  26.736d {+01h 46m 57s} (current),
                  25.608d {+01h 42m 26s} (1950)
GRB_DEC:         +69.492d {+69d 29' 30"} (J2000),
                 +69.533d {+69d 31' 59"} (current),
                 +69.242d {+69d 14' 30"} (1950)
GRB_DATE:        14582 TJD;   117 DOY;   08/04/26
GRB_TIME:        48202.94 SOD {13:23:22.94} UT
TRIGGER_INDEX:   10411
GRB_PHI:         -98.79 [deg]
GRB_THETA:        29.67 [deg]
DELTA_TIME:      71.00 [sec]
TRIGGER_DUR:     0.064 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     25.25 [sigma]
IMAGE_SIGNIF:    8.32 [sigma]
LC_URL:          sw00310219000msb.lc
SUN_POSTN:        34.35d {+02h 17m 23s}  +13.74d {+13d 44' 41"}
SUN_DIST:         56.00 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.18d {+19h 00m 44s}  -26.02d {-26d 01' 20"}
MOON_DIST:       118.29 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.73,  7.13 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       58.75, 52.84 [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 = 185.68,17.84 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:27:14 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.566d {+01h 46m 16s} (J2000)
POINT_DEC:       +69.514d {+69d 30' 49"} (J2000)
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  48425.17 SOD {13:27:05.17} UT,   222.5 [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:     Sat 26 Apr 08 13:29:19 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.566d {+01h 46m 16s} (J2000)
POINT_DEC:       +69.514d {+69d 30' 49"} (J2000)
POINT_ROLL:      170.876d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  48428.51 SOD {13:27:08.51} UT,   225.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.172
N_STARS:         119
X_OFFSET:        632 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1423 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00310219000msufc0225.fits
SUN_POSTN:        34.35d {+02h 17m 24s}  +13.75d {+13d 44' 43"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.20d {+19h 00m 49s}  -26.02d {-26d 01' 08"}
MOON_DIST:       118.28 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.73,  7.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:29:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.566d {+01h 46m 16s} (J2000)
POINT_DEC:       +69.514d {+69d 30' 49"} (J2000)
POINT_ROLL:      170.876d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  48428.51 SOD {13:27:08.51} UT,   225.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.172
N_STARS:         119
X_OFFSET:        632 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1423 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00310219000msufc0225.fits
SUN_POSTN:        34.35d {+02h 17m 24s}  +13.75d {+13d 44' 43"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.21d {+19h 00m 51s}  -26.02d {-26d 01' 05"}
MOON_DIST:       118.27 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.73,  7.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.86 [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:     Sat 26 Apr 08 13:30:39 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.566d {+01h 46m 16s} (J2000)
POINT_DEC:       +69.514d {+69d 30' 49"} (J2000)
ROLL:            170.876d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  48428.51 SOD {13:27:08.51} UT,   225.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     230909231
X_OFFSET:        951 [pixels]
Y_OFFSET:        783 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1111
Y_GRB_POS:       943
BINNING_INDEX:   1
IM_URL:          sw00310219000msuni0225.fits
SUN_POSTN:        34.35d {+02h 17m 24s}  +13.75d {+13d 44' 44"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.22d {+19h 00m 52s}  -26.02d {-26d 01' 02"}
MOON_DIST:       118.27 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.73,  7.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.86 [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 26 Apr 08 13:30:53 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.566d {+01h 46m 16s} (J2000)
POINT_DEC:       +69.514d {+69d 30' 49"} (J2000)
ROLL:            170.876d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  48428.51 SOD {13:27:08.51} UT,   225.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     230909231
X_OFFSET:        951 [pixels]
Y_OFFSET:        783 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1111
Y_GRB_POS:       943
BINNING_INDEX:   1
IM_URL:          sw00310219000msuni0225.fits
SUN_POSTN:        34.35d {+02h 17m 24s}  +13.75d {+13d 44' 44"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.22d {+19h 00m 53s}  -26.02d {-26d 01' 00"}
MOON_DIST:       118.27 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.73,  7.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:40:14 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 59"} (J2000)
POINT_ROLL:      170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49071.96 SOD {13:37:51.96} UT,   869.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.976
N_STARS:         121
X_OFFSET:        632 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1423 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00310219000msufc0869.fits
SUN_POSTN:        34.36d {+02h 17m 25s}  +13.75d {+13d 44' 51"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.30d {+19h 01m 13s}  -26.00d {-26d 00' 12"}
MOON_DIST:       118.23 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:40:51 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 59"} (J2000)
POINT_ROLL:      170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49071.96 SOD {13:37:51.96} UT,   869.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.976
N_STARS:         121
X_OFFSET:        632 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1423 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00310219000msufc0869.fits
SUN_POSTN:        34.36d {+02h 17m 25s}  +13.75d {+13d 44' 52"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.31d {+19h 01m 14s}  -26.00d {-26d 00' 09"}
MOON_DIST:       118.22 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [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:     Sat 26 Apr 08 13:40:52 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     310219,   Seg_Num: 0
GRB_RA:           26.4993d {+01h 45m 59.8s} (J2000),
                  26.6613d {+01h 46m 38.7s} (current),
                  25.5349d {+01h 42m 08.3s} (1950)
GRB_DEC:         +69.4685d {+69d 28' 06.6"} (J2000),
                 +69.5099d {+69d 30' 35.6"} (current),
                 +69.2183d {+69d 13' 05.8"} (1950)
GRB_ERROR:       2.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  48434.00 SOD {13:27:14.00} UT,   231.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        34.36d {+02h 17m 25s}  +13.75d {+13d 44' 52"}
SUN_DIST:         55.97 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.31d {+19h 01m 14s}  -26.00d {-26d 00' 09"}
MOON_DIST:       118.20 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.71,  7.10 [deg] galactic lon,lat of the burst
ECL_COORDS:       58.69, 52.84 [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:        This position was enhanced using UVOT field astrometry

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:41:36 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 59"} (J2000)
ROLL:            170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49071.96 SOD {13:37:51.96} UT,   869.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     230909874
X_OFFSET:        951 [pixels]
Y_OFFSET:        783 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1111
Y_GRB_POS:       943
BINNING_INDEX:   1
IM_URL:          sw00310219000msuni0869.fits
SUN_POSTN:        34.36d {+02h 17m 26s}  +13.75d {+13d 44' 52"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.32d {+19h 01m 16s}  -26.00d {-26d 00' 05"}
MOON_DIST:       118.22 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [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 26 Apr 08 13:41:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 59"} (J2000)
ROLL:            170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49071.96 SOD {13:37:51.96} UT,   869.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     230909874
X_OFFSET:        951 [pixels]
Y_OFFSET:        783 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1111
Y_GRB_POS:       943
BINNING_INDEX:   1
IM_URL:          sw00310219000msuni0869.fits
SUN_POSTN:        34.36d {+02h 17m 26s}  +13.75d {+13d 44' 53"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.32d {+19h 01m 17s}  -26.00d {-26d 00' 03"}
MOON_DIST:       118.22 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:46:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 58"} (J2000)
POINT_ROLL:      170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49177.96 SOD {13:39:37.96} UT,   975.3 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        3.290
N_STARS:         150
X_OFFSET:        632 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1423 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00310219000msufc0975.fits
SUN_POSTN:        34.36d {+02h 17m 26s}  +13.75d {+13d 44' 57"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.36d {+19h 01m 27s}  -25.99d {-25d 59' 39"}
MOON_DIST:       118.20 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Apr 08 13:47:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 58"} (J2000)
POINT_ROLL:      170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49177.96 SOD {13:39:37.96} UT,   975.3 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        3.290
N_STARS:         150
X_OFFSET:        632 [pixels]
Y_OFFSET:        464 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1423 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00310219000msufc0975.fits
SUN_POSTN:        34.36d {+02h 17m 26s}  +13.75d {+13d 44' 57"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.37d {+19h 01m 29s}  -25.99d {-25d 59' 36"}
MOON_DIST:       118.20 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [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:     Sat 26 Apr 08 13:48:09 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 58"} (J2000)
ROLL:            170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49177.96 SOD {13:39:37.96} UT,   975.3 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     230909980
X_OFFSET:        951 [pixels]
Y_OFFSET:        783 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1111
Y_GRB_POS:       943
BINNING_INDEX:   1
IM_URL:          sw00310219000msuni0975.fits
SUN_POSTN:        34.36d {+02h 17m 27s}  +13.75d {+13d 44' 58"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.38d {+19h 01m 30s}  -25.99d {-25d 59' 31"}
MOON_DIST:       118.19 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [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 26 Apr 08 13:48:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     310219,   Seg_Num: 0
POINT_RA:         26.561d {+01h 46m 15s} (J2000)
POINT_DEC:       +69.516d {+69d 30' 58"} (J2000)
ROLL:            170.872d
IMG_START_DATE:  14582 TJD;   117 DOY;   08/04/26
IMG_START_TIME:  49177.96 SOD {13:39:37.96} UT,   975.3 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     230909980
X_OFFSET:        951 [pixels]
Y_OFFSET:        783 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1111
Y_GRB_POS:       943
BINNING_INDEX:   1
IM_URL:          sw00310219000msuni0975.fits
SUN_POSTN:        34.36d {+02h 17m 27s}  +13.75d {+13d 44' 58"}
SUN_DIST:         56.02 [deg]   Sun_angle= 0.5 [hr] (West of Sun)
MOON_POSTN:      285.38d {+19h 01m 31s}  -25.99d {-25d 59' 30"}
MOON_DIST:       118.19 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      127.72,  7.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       58.77, 52.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #7639
H. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (MSSL), J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), S. R. Oates (UCL-MSSL), C. Pagani (PSU), D. M. Palmer (LANL), D. Perez (U Leicester), R. L. C. Starling (U Leicester), G. Tagliaferri (INAF-OAB), T. N. Ukwatta (GSFC/GWU) and P. A. Ward (MSSL-UCL) report on behalf of the Swift Team:
At 13:23:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080426 (trigger=310219). Swift slewed to the burst after a brief delay due to Earth limb constraint. The BAT on-board calculated location is RA, Dec 26.574, +69.492 which is
```
   RA(J2000) = 01h 46m 18s
   Dec(J2000) = +69d 29' 30"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 2 sec. The peak count rate was ~7500 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 13:27:05.2 UT, 222.5 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 26.49931, 69.46856 which is equivalent to:
```
   RA(J2000)  = 01h 45m 59.83s
   Dec(J2000) = +69d 28' 06.8"
```
with an uncertainty of 2.8 arcseconds (radius, 90% containment). This location is 126 arcseconds from the BAT onboard position, within the BAT error circle.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 3.65e+21 cm^-2 (Kalberla et al. 2005), so we cannot constrain the redshift at this time using the relation from Grupe et al. (2007). A summary of the promptly downlinked data is given at http://www.swift.ac.uk/sper/310219/.
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)filter starting 226 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The typical 3-sigma upper limit has been about 18.5 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.79.
Burst Advocate for this burst is H. Ziaeepour (hz AT mssl.ucl.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #7640
J. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU), H. Ziaeepour (UCL-MSSL) (i.e. the Swift-BAT team):
Using the data set from T-119 to T+183 sec from recent telemetry downlinks, we report further analysis of BAT GRB 080426 (trigger #310219) (Ziaeepour, et al., GCN Circ. 7639). The BAT ground-calculated position is RA, Dec = 26.510, 69.469 deg which is
```
   RA(J2000)  =  01h 46m 02.4s 
   Dec(J2000) = +69d 28' 07.9" 
```
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 43%.
The mask-weighted light curve shows a single spike starting at T+0 and ending at T+2.0 sec. The lag analysis yields:
```
  Lag31 = 88 +/- 9 ms  (50-100 to 15-25 keV bands)
  Lag21 = 74 +/- 6 ms  (25-50  to 15-25 keV bands)
```
T90 (15-350 keV) is 1.7 +- 0.4 sec (estimated error including systematics). While the T90 value puts this burst in the middle of the long and Short burst T90-distribution peaks, the lag value puts this burst in the Long burst class.
The time-averaged spectrum from T+0.1 to T+2.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.98 +- 0.13. The fluence in the 15-150 keV band is 3.7 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.08 sec in the 15-150 keV band is 4.8 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
We note that this is an unusual burst. The T90 for the 50-300 keV BATSE range is 1.3 sec which would put it in the short class in that era. However, the long lag and a spectrum that is not hard lead us to believe it is in the long class.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/310219/BA/
GCN Circular #7641
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 894 s of overlapping XRT Photon Counting mode and UVOT data for GRB 080426, 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 = 26.49890, +69.46823 which is equivalent to:
```
RA (J2000): 01h 45m 59.74s
Dec (J2000): +69d 28' 05.6"
```
with an uncertainty of 1.8 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method.
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #7642
S.R. Oates (UCL-MSSL) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift/UVOT team.
The Swift/UVOT began settled observations the field of GRB 080426 (trigger 310219) 226 seconds after the BAT trigger (Ziaeepour, et al., GCN Circ. 7639). No afterglow is detected at the enhanced XRT position (Beardmore, et al., GCN Circ. 7641) in any of the UVOT filters. The 3 sigma upper limits are given below:
```
Filter   T_start  T_stop    Exp.    Mag UL (3sig)
            (s)    (s)
------------------------------------------------
white      226     326       98        >20.38
white      446     7457     362        >20.86
v          333     7868    1316        >19.98
b          431     7253     303        >20.01
u          407     7047     333        >19.79
uvw1       382     6843     352        >19.99
uvm2       357     7969     407        >19.94
uvw2       462     7663     510        >20.26
-------------------------------------------------
```
These upper limits are not corrected for the Galactic extinction in the line of sight, corresponding to a reddening of E(B-V)= 0.798 mag (Schlegel et al., 1998, ApJS, 500, 525). The photometry is based on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular #7643
A.P. Beardmore (U. Leicester) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift-XRT team :
The Swift-XRT began observing GRB 080426 (trigger=310219, Ziaeepour et al. GCN Circ. 7639) in Photon Counting mode, 230 s after the BAT trigger. The best XRT position for this burst is the UVOT-enhanced position reported by Beardmore et al. (GCN Circ. 7641).
Three orbits of data out to T+13 ks, totalling 5.7 ks of exposure, reveal a light curve which follows a simple power-law decay, with an index of -1.07 +/- 0.08.
The spectrum from the first three orbits is well fit by an absorbed power-law model, with a photon index of 2.01 +/- 0.25 and column density of (5.3 +/- 1.3)e21 cm^-2, which is slightly in excess of the average Galactic column density in this direction of 3.7e21 cm^-2. The observed (unabsorbed) 0.3-10 keV flux is 5.1e-12 (9.1e-12) erg cm^-2 s^-1.
If the burst continues to decay at the same rate, we predict an XRT count rate of 2.0e-3 count/s at T+24 hours, which corresponds to an observed 0.3-10 keV flux of approximately 1.2e-13 erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular #7644
A. de Ugarte Postigo (ESO), D. A. Kann (TLS Tautenburg), A.J. Castro-Tirado (IAA-CSIC, Granada), A. Aguirre (CAHA), C. Jordi (U. Barcelona) report on behalf of a larger collaboration:
We have observed the XRT error circle (Beardmore et al. GCN 7641) of the possible intermediate GRB 080426 (H. Ziaeepour et al. GCN 7639, J. Cummings et al. GNC 7640) with the 2.2m telescope at Calar Alto Observatory (Almer=EDa, Spain) at high airmass but good conditions.
The observations started at 26 April 19:53:33 UT and were carried out in B, V, R and I bands. In an I-band combined frame comprised of 11x300s with mean epoch 7.50 hours after the burst, we do not detect any source within the XRT error box down to a limiting magnitude of I~22.5.
Further analysis is ongoing. This message may be cited.
GCN Report 130.1
GCN_Report 130.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_130_1.pdf by H. Ziaeepour at UCL/MSSL titled: "Final Swift observations on GRB 080426"

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