Gamma-ray Burst 080320

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE


TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 04:38:04 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     306858,   Seg_Num: 0
GRB_RA:          177.780d {+11h 51m 07s} (J2000),
                 177.888d {+11h 51m 33s} (current),
                 177.121d {+11h 48m 29s} (1950)
GRB_DEC:         +57.144d {+57d 08' 38"} (J2000),
                 +57.098d {+57d 05' 53"} (current),
                 +57.422d {+57d 25' 19"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       7159 [cnts]    Image_Peak=245 [image_cnts]
TRIGGER_DUR:     1.408 [sec] 
TRIGGER_INDEX:   472     E_range: 25-100 keV
BKG_INTEN:       70772 [cnts]
BKG_TIME:        16637.34 SOD {04:37:17.34} UT
BKG_DUR:         16 [sec]
GRB_DATE:        14545 TJD;    80 DOY;   08/03/20
GRB_TIME:        16658.46 SOD {04:37:38.46} UT
GRB_PHI:         -178.36 [deg]
GRB_THETA:        22.07 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.94 [sigma]
IMAGE_SIGNIF:    7.64 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +2  +2  +0  +0 +54  +1 
SUN_POSTN:       359.95d {+23h 59m 48s}   -0.02d {-00d 01' 17"}
SUN_DIST:        122.90 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.27d {+10h 49m 04s}   +6.07d {+06d 04' 15"}
MOON_DIST:        52.48 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.44, 58.13 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      146.90, 49.67 [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 = 282.09,20.59 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 04:40:35 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.773d {+11h 51m 06s} (J2000)
POINT_DEC:       +57.154d {+57d 09' 14"} (J2000)
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16829.45 SOD {04:40:29.45} UT,   171.0 [sec] since BAT Trigger Time
COUNTS:          2    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 20 Mar 08 04:41:28 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     306858,   Seg_Num: 0
GRB_RA:          177.780d {+11h 51m 07s} (J2000),
                 177.888d {+11h 51m 33s} (current),
                 177.121d {+11h 48m 29s} (1950)
GRB_DEC:         +57.144d {+57d 08' 38"} (J2000),
                 +57.098d {+57d 05' 53"} (current),
                 +57.422d {+57d 25' 19"} (1950)
GRB_DATE:        14545 TJD;    80 DOY;   08/03/20
GRB_TIME:        16658.46 SOD {04:37:38.46} UT
TRIGGER_INDEX:   472
GRB_PHI:         -178.36 [deg]
GRB_THETA:        22.07 [deg]
DELTA_TIME:      -31.00 [sec]
TRIGGER_DUR:     1.408 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.94 [sigma]
IMAGE_SIGNIF:    7.64 [sigma]
LC_URL:          sw00306858000msb.lc
SUN_POSTN:       359.95d {+23h 59m 48s}   -0.02d {-00d 01' 14"}
SUN_DIST:        122.90 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.29d {+10h 49m 10s}   +6.06d {+06d 03' 25"}
MOON_DIST:        52.49 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.44, 58.13 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      146.90, 49.67 [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 = 282.09,20.59 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 04:42:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.774d {+11h 51m 06s} (J2000)
POINT_DEC:       +57.154d {+57d 09' 13"} (J2000)
POINT_ROLL:      357.405d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16834.81 SOD {04:40:34.81} UT,   176.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.135
N_STARS:         22
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0176.fits
SUN_POSTN:       359.95d {+23h 59m 49s}   -0.02d {-00d 01' 13"}
SUN_DIST:        122.89 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.30d {+10h 49m 13s}   +6.05d {+06d 03' 05"}
MOON_DIST:        52.50 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.44, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.88, 49.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 04:43:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.774d {+11h 51m 06s} (J2000)
POINT_DEC:       +57.154d {+57d 09' 13"} (J2000)
POINT_ROLL:      357.405d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16834.81 SOD {04:40:34.81} UT,   176.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.135
N_STARS:         22
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0176.fits
SUN_POSTN:       359.95d {+23h 59m 49s}   -0.02d {-00d 01' 12"}
SUN_DIST:        122.89 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.31d {+10h 49m 14s}   +6.05d {+06d 02' 58"}
MOON_DIST:        52.50 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.44, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.88, 49.68 [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 20 Mar 08 04:43:55 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.774d {+11h 51m 06s} (J2000)
POINT_DEC:       +57.154d {+57d 09' 13"} (J2000)
ROLL:            357.405d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16834.81 SOD {04:40:34.81} UT,   176.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     227680837
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0176.fits
SUN_POSTN:       359.95d {+23h 59m 49s}   -0.02d {-00d 01' 12"}
SUN_DIST:        122.89 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.31d {+10h 49m 15s}   +6.05d {+06d 02' 49"}
MOON_DIST:        52.51 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.44, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.88, 49.68 [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 20 Mar 08 04:44:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.774d {+11h 51m 06s} (J2000)
POINT_DEC:       +57.154d {+57d 09' 13"} (J2000)
ROLL:            357.405d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16834.81 SOD {04:40:34.81} UT,   176.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     227680837
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0176.fits
SUN_POSTN:       359.95d {+23h 59m 49s}   -0.02d {-00d 01' 11"}
SUN_DIST:        122.89 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.32d {+10h 49m 16s}   +6.04d {+06d 02' 42"}
MOON_DIST:        52.51 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.44, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.88, 49.68 [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:     Thu 20 Mar 08 04:51:56 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.778d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
POINT_ROLL:      357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16940.95 SOD {04:42:20.95} UT,   282.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.109
N_STARS:         22
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0282.fits
SUN_POSTN:       359.96d {+23h 59m 50s}   -0.02d {-00d 01' 04"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.38d {+10h 49m 30s}   +6.01d {+06d 00' 50"}
MOON_DIST:        52.53 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 04:52:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.778d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
POINT_ROLL:      357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16940.95 SOD {04:42:20.95} UT,   282.5 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.109
N_STARS:         22
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0282.fits
SUN_POSTN:       359.96d {+23h 59m 50s}   -0.02d {-00d 01' 03"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.38d {+10h 49m 31s}   +6.01d {+06d 00' 43"}
MOON_DIST:        52.53 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 20 Mar 08 04:52:55 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     306858,   Seg_Num: 0
GRB_RA:          177.7355d {+11h 50m 56.5s} (J2000),
                 177.8435d {+11h 51m 22.4s} (current),
                 177.0754d {+11h 48m 18.0s} (1950)
GRB_DEC:         +57.1579d {+57d 09' 28.4"} (J2000),
                 +57.1122d {+57d 06' 43.9"} (current),
                 +57.4360d {+57d 26' 09.6"} (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:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16840.00 SOD {04:40:40.00} UT,   181.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       359.96d {+23h 59m 50s}   -0.02d {-00d 01' 03"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.38d {+10h 49m 32s}   +6.01d {+06d 00' 36"}
MOON_DIST:        52.53 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.47, 58.11 [deg] galactic lon,lat of the burst
ECL_COORDS:      146.86, 49.67 [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:     Thu 20 Mar 08 04:53:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.778d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
ROLL:            357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16940.95 SOD {04:42:20.95} UT,   282.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     227680943
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0282.fits
SUN_POSTN:       359.96d {+23h 59m 50s}   -0.02d {-00d 01' 02"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.39d {+10h 49m 33s}   +6.01d {+06d 00' 29"}
MOON_DIST:        52.53 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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:     Thu 20 Mar 08 04:53:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.778d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
ROLL:            357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  16940.95 SOD {04:42:20.95} UT,   282.5 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     227680943
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0282.fits
SUN_POSTN:       359.96d {+23h 59m 50s}   -0.02d {-00d 01' 03"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.39d {+10h 49m 33s}   +6.01d {+06d 00' 33"}
MOON_DIST:        52.53 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 20 Mar 08 04:56:25 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
POINT_ROLL:      357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17525.85 SOD {04:52:05.85} UT,   867.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.129
N_STARS:         24
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0867.fits
SUN_POSTN:       359.96d {+23h 59m 51s}   -0.02d {-00d 01' 00"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.41d {+10h 49m 39s}   +6.00d {+05d 59' 44"}
MOON_DIST:        52.54 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 04:56:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
POINT_ROLL:      357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17525.85 SOD {04:52:05.85} UT,   867.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.129
N_STARS:         24
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0867.fits
SUN_POSTN:       359.96d {+23h 59m 51s}   -0.02d {-00d 00' 59"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.42d {+10h 49m 40s}   +5.99d {+05d 59' 37"}
MOON_DIST:        52.54 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 20 Mar 08 04:57:36 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
ROLL:            357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17525.85 SOD {04:52:05.85} UT,   867.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     227681528
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0867.fits
SUN_POSTN:       359.96d {+23h 59m 51s}   -0.02d {-00d 00' 58"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.42d {+10h 49m 41s}   +5.99d {+05d 59' 26"}
MOON_DIST:        52.54 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 20 Mar 08 04:57:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
ROLL:            357.410d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17525.85 SOD {04:52:05.85} UT,   867.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     227681528
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0867.fits
SUN_POSTN:       359.96d {+23h 59m 51s}   -0.02d {-00d 00' 58"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.42d {+10h 49m 42s}   +5.99d {+05d 59' 22"}
MOON_DIST:        52.54 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 #7472
F. Yuan (U Mich), E.S. Rykoff (UCSB), W. Rujopakarn (Steward), report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080320 (Swift trigger 306858), producing images beginning 6.5 s after the GCN notice time. An automated response took the first image at 04:38:10.5 UT, 32.1 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 20 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, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 16.4-17.5; we set the following specific limits.
```
start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
04:38:10.5   04:38:15.5         5     16.5           32.1       N
04:38:10.4   04:39:17.5        67     18.1           32.0       Y
```

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 05:02:09 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
POINT_ROLL:      357.409d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17631.82 SOD {04:53:51.82} UT,   973.4 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.050
N_STARS:         23
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0973.fits
SUN_POSTN:       359.97d {+23h 59m 52s}   -0.02d {-00d 00' 54"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.46d {+10h 49m 50s}   +5.97d {+05d 58' 19"}
MOON_DIST:        52.56 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 20 Mar 08 05:02:30 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
POINT_ROLL:      357.409d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17631.82 SOD {04:53:51.82} UT,   973.4 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.050
N_STARS:         23
X_OFFSET:        406 [pixels]
Y_OFFSET:        603 [pixels]
X_MAX:           1365 [pixels]
Y_MAX:           1562 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00306858000msufc0973.fits
SUN_POSTN:       359.97d {+23h 59m 52s}   -0.02d {-00d 00' 53"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.46d {+10h 49m 51s}   +5.97d {+05d 58' 14"}
MOON_DIST:        52.56 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 20 Mar 08 05:03:15 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
ROLL:            357.409d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17631.82 SOD {04:53:51.82} UT,   973.4 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     227681634
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0973.fits
SUN_POSTN:       359.97d {+23h 59m 52s}   -0.01d {-00d 00' 52"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.47d {+10h 49m 52s}   +5.97d {+05d 58' 03"}
MOON_DIST:        52.56 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 20 Mar 08 05:03:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     306858,   Seg_Num: 0
POINT_RA:        177.777d {+11h 51m 07s} (J2000)
POINT_DEC:       +57.156d {+57d 09' 20"} (J2000)
ROLL:            357.409d
IMG_START_DATE:  14545 TJD;    80 DOY;   08/03/20
IMG_START_TIME:  17631.82 SOD {04:53:51.82} UT,   973.4 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     227681634
X_OFFSET:        725 [pixels]
Y_OFFSET:        922 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       885
Y_GRB_POS:       1082
BINNING_INDEX:   1
IM_URL:          sw00306858000msuni0973.fits
SUN_POSTN:       359.97d {+23h 59m 52s}   -0.01d {-00d 00' 52"}
SUN_DIST:        122.88 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      162.47d {+10h 49m 53s}   +5.97d {+05d 57' 58"}
MOON_DIST:        52.56 [deg]
MOON_ILLUM:      97 [%]
GAL_COORDS:      138.43, 58.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      146.89, 49.68 [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 #7473
D. Grupe (PSU), D. N. Burrows (PSU), M. M. Chester (PSU), N. Gehrels (NASA/GSFC), S. Immler (CRESST/GSFC/UMD), J. A. Kennea (PSU), C. B. Markwardt (CRESST/GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), J. L. Racusin (PSU), M. Stamatikos (NASA/ORAU), T. N. Ukwatta (GSFC/GWU), D. E. Vanden Berk (PSU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 04:37:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080320 (trigger=306858). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 177.780, +57.144 which is
```
   RA(J2000) = 11h 51m 07s
   Dec(J2000) = +57d 08' 38"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a FRED structure with a duration of about 25 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 04:40:29.4 UT, 171.0 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 177.73502, 57.15776 which is equivalent to:
```
   RA(J2000)  = 11h 50m 56.41s
   Dec(J2000) = +57d 09' 27.9"
```
with an uncertainty of 2.5 arcseconds (radius, 90% containment). This location is 100 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 1.35e+20 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/306858/.
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 177 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle but does not overlap the XRT error circle. 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 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 0.01.
Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #7474
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB080320 prior to the burst. As these data should be useful as a pre-burst comparison and for calibrating photometry, we are supplying the images and photometry measurements for this GRB field to the community.
Data from the SDSS, including 5 FITS images, 3 JPGS, and 3 files of photometry and astrometry, are being placed at http://mizar.as.arizona.edu/~grb/public/GRB080320
We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=177.780 (11:51:07.2), dec=57.1440 (57:08:38.4); Swift-BAT Trigger 306858), as well as 3 gri color-composite JPGs (with different stretches). The units in the FITS images are nanomaggies per pixel. A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS astrometric information.
In the file GRB080320_sdss.calstar.dat, we report photometry and astrometry of 178 bright stars (r<20.5) within 15' of the burst location. The magnitudes presented in this file are asinh magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118, 1406). Beware that some of these stars are not well-detected in the u-band; use the errors and object flags to monitor data quality.
In the files GRB080320_sdss.objects_flux.dat and GRB080320_sdss.objects_magnitudes.dat, we report photometry of 349 objects detected within 6' of the GRB position. We have removed saturated objects and objects with model magnitudes fainter than 23.0 in the r-band. The fluxes listed in GRB080320_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB080320_sdss.objects_magnitudes.dat are asinh magnitudes.
All quantities reported are standard SDSS photometry, meaning that they are very close to AB zeropoints and magnitudes are quoted in asinh magnitudes. Photometric zeropoints are known to about 2% rms. None of the photometry is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis (1998) predictions for this region are A_U=0.079 mag, A_g=0.058 mag, A_r = 0.042 mag, A_i=0.032 mag, and A_z=0.023 mag.
The file GRB080320_sdss.spectro.dat contains a list of the 6 objects with SDSS spectroscopy within 6 arcminutes of the GRB position. In addition to the redshift and 1-sigma error for each object, this file also lists the object spectroscopic classification.
SDSS astrometry is generally better than 0.1 arcsecond per coordinate. Users requiring high precision astrometry should take note that the SDSS astrometric system can differ from other systems such as those used in other notices; we have not checked the offsets in this region.
More detailed information pertaining to our SDSS GRB releases can be found in our initial data release paper (Cool et al. 2006, PASP 118, 733). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr5.
These data have been reduced using a slightly different pipeline than that used for SDSS public data releases. We cannot guarantee that the values here will exactly match those in the data release in which these data are included. In particular, we expect the photometric calibrations to differ by of order 0.01 mag.
This note may be cited, but please also cite the SDSS data release paper, Adelman-McCarthy et al. (2007, ApJS, 172, 634), when using the data or referring to the technical documentation.
GCN Circular #7478
Martin Jelinek, Alberto J. Castro-Tirado (IAA-CSIC Granada), and Jorge Pl=E1 (IAC La Laguna), on behalf of a larger collaboration, report:
"We observed the XRT localization of the GRB080320 (Grupe et al. GCN 7473) with the 0.8m IAC80 at Obs. del Teide in Tenerife, with exposure mean time 5:33UT (i.e. 1hour after the GRB). We do not detect any source within or near the XRT error box down to the limiting magnitude of R~20.0."
this message may be cited
GCN Circular #7479
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 995 s of overlapping XRT Photon Counting mode and UVOT data for GRB 080320, 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 = 177.73526, +57.15746 which is equivalent to:
```
RA (J2000): 11h 50m 56.46s
Dec (J2000): +57d 09' 26.8"
```
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 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 #7480
N. R. Tanvir, P. T. O'Brien, J. Osborne and P. Evans (U. Leicester) note:
We note here is an SDSS source in the centre of the UVOT enhanced XRT error circle (GCN 7479). The source is reported as having r=22.38 and a photometric redshift estimate of z=0.35+/-0.13 according to the SDSS web site:
http://cas.sdss.org/dr6/en/tools/explore/obj.asp?id=587731890577605599
A provisional analysis of Gemini-N/GMOS observations obtained about 90 mins post-burst also shows this source (at roughly the same magnitude), but nothing else in the error circle.
If this is the host, then the photo-z is interestingly low, and the burst interestingly faint in the optical.
Further analysis is ongoing.
GCN Circular #7488
N. R. Tanvir, E. Rol (U. Leicester), A. Stephens (Gemini), report on behalf of a larger collaboration:
We obtained griz observations of the field of GRB 080320 starting approximately 80 mins post-burst with Gemini-N/GMOS. Conditions were rather poor, with some cirrus, which reduced the depth of the images. A 2nd epoch of i-band imaging was obtained 9 hours post-burst.
A fading point source is seen in both i-band images, somewhat outside the enhanced XRT error circle (GCN 7479). The position (J2000) of this counterpart, with respect to nearby SDSS stars, is (to 0.25 arcsec in each coordinate):
```
 RA =  11 50 56.427
 dec= +57 09 23.90
```
The SDSS galaxy noted in GCN 7480 is about 3 arcsec away from the counterpart, and therefore probably unrelated to it.
Preliminary photometry (again relative to SDSS field stars) gives i'=22.9, and fading between the epochs of 0.37+/-0.03 mag. This relatively slow rate of fading could indicate a contribution from a host galaxy. The counterpart is seen in the z-band, but is absent (or very faint) in the r-band image with a limit of about r~24. This red r-i colour could be explained by a Lyman-alpha break if the redshift is z~4.5 to 5.
Further analysis is ongoing.
GCN Circular #7489
D. Malesani (DARK), A. A. Djupvik, J. Niemela (NOT), J. P. U. Fynbo (DARK), report on behalf of a larger collaboration:
We observed the field of GRB 080320 (Grupe et al., GCN 7473) with the Nordic Optical Telescope. R-band observations were carried out with the StanCam instrument, with mean time 2008 March 20.254 UT (1.47 hr after the GRB).
We do not detect any object at the position of the afterglow reported by Tanvir et al. (GCN 7488) nor inside the XRT error circle (Goad et al., GCN 7479). Our limiting magnitude is R=22 (based on USNO-B1), consistent with the nearly-simultaneous measurement of Tanvir et al. (GCNs 7480, 7488).
GCN Circular #7491
Adria C. Updike, Brian C. Donehew, Ian Oliver, and Dieter H. Hartmann (Clemson University) report:
We used the Kitt Peak 2.1m telescope and the FLAMINGOS instrument in NIR imaging mode to obtain J-band exposures of the field of GRB 080320 (GCN 7473, Grupe et al.). In 80 minutes of stacked exposures, we marginally detect the afterglow (GCN 7488, Tanvir et al.) at J ~ 20 (using a 2MASS comparison star located at RA=11:50:47.4, Dec=+57:10:07.41). The midtime of the stacked exposures was ~3 hours after the trigger. Further analysis is ongoing.
This message may be cited.
GCN Circular #7492
G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of the Super-LOTIS Collaboration, report:
The robotic 0.6-m Super-LOTIS telescope began observing the error box of GRB 080320 (Swift Trigger 306858, Grupe et al. GCN 7473) at 04:38:34.3 UT, 56.3 seconds after the trigger. Our initial observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all in the R-band.
We do not detect any variable sources or afterglow candidates within the refined XRT error box (Goad et al. GCN 7479) or at the location of the OT candidate (Tanvir et al. GCN 7488, Updike et al. GCN 7491) in any of our single exposures or combined exposures to the following 3-sigma limiting magnitudes:
```
t_start (UT)    t_end (UT)     exp t (s)     t_start-t_0 (s)    Limit
       coadd?
----------------------------------------------------------------------------------------------------------
04:38:34.3     04:38:44.3     10.0           56.3                R > 17.7      N
04:39:59.3     04:40:19.3     20.0           141.3              R > 18.3      N
04:42:13.7     04:43:13.7     60.0           275.7              R > 19.0      N
04:38:34.3     04:39:52.6     50.0           56.3                R > 18.7      Y
04:39:59.3     04:42:07.0     100.0         141.3               R > 19.4      Y
04:42:13.7     04:47:41.5     300.0         275.7               R > 20.0      Y
```
GCN Circular #7494
Dirk Grupe reports on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 080320 (trigger=306858; Grupe et al., GCN Circ 7473) at 04:40:29.4 UT, 171.0 seconds after the BAT trigger.
The astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is: RA, Dec = 177.7353, +57.1574 which is equivalent to:
```
RA (J2000):  11 50 56.46
Dec (J2000): +57 09 26.8
```
with an uncertainty of 1.4 arcsec (radius, 90% confidence).
The 0.3-10 keV X-ray light curve starts with three flares up to 12 counts/s. The afterglow decays very fast and started to flatten at the end of the first orbit about 1000 s after the burst. The light curve is currently decaying with a shallow decay slope of 0.63 +/- 0.05.
The spectrum of the Photon Counting data of the first three orbits can be well fitted by an absorbed single powerlaw with a photon index Gamma = 1.96 +/- 0.20 and column density of (6.9 +/- 4.0)e20 cm-2 This is slightly in excess of the Galactic column density of 1.35e20 cm-2 in this direction. Using this spectrum we estimated a count rate to flux conversion of 1 count/s converts to 4.22e-11 ergs/cm2/s.
If the underlying powerlaw decay continues as is, we predict an XRT count rate of 0.026 counts/s at T+24 hours or 1.1e-12 erg/s/cm2.
GCN Circular #7505
K. McLean (GSFC/UMD), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-119 to T+183 sec from the telemetry downlinks, we report further analysis of BAT GRB 080320 (trigger #306858) (Grupe, et al., GCN Circ. 7473). The BAT ground-calculated position is RA, Dec = 177.763, 57.162 deg, which is
```
   RA(J2000)  =  11h 51m 03.1s 
   Dec(J2000) = +57d 09' 42.6" 
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 93%.
The mask-weighted light curve shows a FRED peak starting at ~T-5 sec, peaking at ~T+0, and ending at ~T+35 sec. There a possible (3 sigma) precursor peak at ~T-55 sec with a width of about 5 sec. T90 (15-350 keV) is 14 +- 2 sec (estimated error including systematics).
The time-averaged spectrum from T-1.7 to T+13.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.70 +- 0.22. The fluence in the 15-150 keV band is 2.7 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.15 sec in the 15-150 keV band is 0.6 +- 0.1 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/306858/BA/
GCN Circular #7637
A. Melandri (Liverpool JMU), A. Gomboc (Ljubljana), C. Guidorzi (INAF-OAB), R.J. Smith, I.A. Steele, C.G. Mundell, D.F. Bersier, M.F. Bode, M.J. Burgdorf, S. Kobayashi, C.J. Mottram (Liverpool JMU), P. O'Brien, N. Bannister, N. Tanvir (U. Leicester) report on behalf of larger GRB collaboration :
On 2008 March 20 (06:00:59UT) we observed the field of GRB 080320 (trigger=306858, Grupe et al. GCN 7473) with the Faulkes Telescope North. Observations constited of 10x300s exposures acquired using the SDSS-i' filter.
In our coadded frame we do not detect any source inside the refined XRT error box (Goad et al. GCN 7479) or at the position of the faint infrared afterglow reported by Tanvir et al. (GCN 7488) and Updike et al. (GCN 7491), down to the limiting magnitude reported below.
```
Telescope        Filter  DT_mean[min]  Exposure(s)    M_lim (3-sigma)

----------------------------------------------------------------------
Faulkes North      i'       108.4         3000         20.4
----------------------------------------------------------------------
```
GCN Report 126.1
GCN_Report 126.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_126_1.pdf by D. Grupe at PSU titled: "Final Swift Observations of GRB 080320"

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Jochen Greiner, last update: 22-Apr-2008 [Disclaimer]