Gamma-ray Burst 090307

(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 07 Mar 09 03:52:45 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     345551,   Seg_Num: 0
GRB_RA:          244.979d {+16h 19m 55s} (J2000),
                 245.122d {+16h 20m 29s} (current),
                 244.202d {+16h 16m 48s} (1950)
GRB_DEC:         -28.644d {-28d 38' 38"} (J2000),
                 -28.666d {-28d 39' 55"} (current),
                 -28.525d {-28d 31' 28"} (1950)
GRB_ERROR:       4.00 [arcmin radius, statistical only]
GRB_INTEN:       54507 [cnts]    Image_Peak=498 [image_cnts]
TRIGGER_DUR:     12.160 [sec] 
TRIGGER_INDEX:   478     E_range: 25-100 keV
BKG_INTEN:       271195 [cnts]
BKG_TIME:        13499.44 SOD {03:44:59.44} UT
BKG_DUR:         64 [sec]
GRB_DATE:        14897 TJD;    66 DOY;   09/03/07
GRB_TIME:        13597.87 SOD {03:46:37.87} UT
GRB_PHI:         164.06 [deg]
GRB_THETA:        22.41 [deg]
SOLN_STATUS:     0x30004083
RATE_SIGNIF:     10.39 [sigma]
IMAGE_SIGNIF:    5.73 [sigma]
MERIT_PARAMS:     +1  +0  +0  +4  +2  -5  +0  +1 +15  +1 
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 47"}
SUN_DIST:         98.48 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      116.58d {+07h 46m 18s}  +22.39d {+22d 23' 19"}
MOON_DIST:       133.49 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.79, 15.13 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      248.03, -7.09 [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 was originally a SubThreshold, but now has been converted to a real GRB Position.  
COMMENTS:        This trigger occurred at longitude,latitude = 50.73,20.53 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is spatially(0.00<0.1deg) and temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=345551).

red DSS finding chart ps-file

GCN NOTICE

TITLE:        GCN/SIMBAD_NED NOTICE
NOTICE_DATE:  Sat Mar  7 03:53:00 UTC 2009
NOTICE_TYPE:  Swift-XRT Position search
TRIGGER_NUM:  345551
RA:           244.9937 (J2000)
DEC:          -28.6338 (J2000)
 
SIMBAD search for XRT_RA,Dec=244.9937,-28.6338,radius=1.0arcmin
 
Num   RA         Dec                    Name                        Type  Num_Pub  Distance

 
 
 
NED search for XRT_RA,Dec=244.9937,-28.6338,radius=1.0arcmin
 
Num    RA           Dec       Name                           Type      Distance

 1   244.992167   -28.643306  NVSS J161958-283835           , RadioS   0.60

GCN NOTICE

TITLE:        GCN/SIMBAD_NED NOTICE
NOTICE_DATE:  Sat Mar  7 03:52:49 UTC 2009
NOTICE_TYPE:  Swift-BAT Position search
TRIGGER_NUM:  345551
RA:           244.9792 (J2000)
DEC:          -28.6441 (J2000)
 
SIMBAD search for BAT_RA,Dec=244.9792,-28.6441,radius=10.0arcmin
 
Num   RA         Dec                    Name                        Type  Num_Pub  Distance

 1 245.06375000 -28.71708333       1RXS J162015.3-284301                X   0      6.24
 2 245.06375000 -28.71708333       1RXS J162015.3-284301                X   0      6.24
 3 245.06463542 -28.71690750                   HD 146974                *   1      6.27
 4 244.90334167 -28.73693889       1RXS J161936.8-284413                X   0      6.85
 5 244.92217208 -28.76674861                 CD-28 12050               IR   0      7.95
 
 
 
NED search for BAT_RA,Dec=244.9792,-28.6441,radius=10.0arcmin
 
Num    RA           Dec       Name                           Type      Distance

 1   244.992167   -28.643306  NVSS J161958-283835           , RadioS   0.70
 2   244.870792   -28.682750  NVSS J161928-284057           , RadioS   6.20
 3   245.051875   -28.724583  NVSS J162012-284328           , RadioS   6.20
 4   244.874208   -28.588389  NVSS J161929-283518           , RadioS   6.50
 5   244.974917   -28.770667  NVSS J161953-284614           , RadioS   7.60
 6   245.102292   -28.561194  NVSS J162024-283340           , RadioS   8.20
 7   245.146208   -28.586778  NVSS J162035-283512           , RadioS   9.40

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Mar 09 03:53:09 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.005d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.633d {-28d 37' 57"} (J2000)
POINT_ROLL:      100.816d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13725.93 SOD {03:48:45.93} UT,   128.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.335
N_STARS:         146
X_OFFSET:        392 [pixels]
Y_OFFSET:        695 [pixels]
X_MAX:           1351 [pixels]
Y_MAX:           1654 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00345551000msufc0128.fits
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 47"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.58d {+07h 46m 19s}  +22.39d {+22d 23' 15"}
MOON_DIST:       133.51 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Mar 09 03:52:58 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     345551,   Seg_Num: 0
GRB_RA:          244.9937d {+16h 19m 58.48s} (J2000),
                 245.1366d {+16h 20m 32.78s} (current),
                 244.2162d {+16h 16m 51.88s} (1950)
GRB_DEC:         -28.6338d {-28d 38' 01.6"} (J2000),
                 -28.6553d {-28d 39' 19.2"} (current),
                 -28.5144d {-28d 30' 51.8"} (1950)
GRB_ERROR:       4.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13734.00 SOD {03:48:54.00} UT,   136.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 47"}
SUN_DIST:         98.47 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      116.58d {+07h 46m 19s}  +22.39d {+22d 23' 17"}
MOON_DIST:       133.50 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.80, 15.13 [deg] galactic lon,lat of the burst
ECL_COORDS:      248.05, -7.08 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This was originally a SubThreshold, but now has been converted to a real GRB Position.  
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.php for details.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Mar 09 03:53:53 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.005d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.633d {-28d 37' 57"} (J2000)
POINT_ROLL:      100.816d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13725.93 SOD {03:48:45.93} UT,   128.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.335
N_STARS:         146
X_OFFSET:        392 [pixels]
Y_OFFSET:        695 [pixels]
X_MAX:           1351 [pixels]
Y_MAX:           1654 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00345551000msufc0128.fits
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 46"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.59d {+07h 46m 21s}  +22.39d {+22d 23' 08"}
MOON_DIST:       133.50 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [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 07 Mar 09 03:54:23 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.005d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.633d {-28d 37' 57"} (J2000)
ROLL:            100.816d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13725.93 SOD {03:48:45.93} UT,   128.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     258090530
X_OFFSET:        711 [pixels]
Y_OFFSET:        1014 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1174
BINNING_INDEX:   1
IM_URL:          sw00345551000msuni0133.fits
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 46"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.59d {+07h 46m 22s}  +22.38d {+22d 23' 03"}
MOON_DIST:       133.50 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [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 07 Mar 09 03:54:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.005d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.633d {-28d 37' 57"} (J2000)
ROLL:            100.816d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13725.93 SOD {03:48:45.93} UT,   128.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     258090530
X_OFFSET:        711 [pixels]
Y_OFFSET:        1014 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1174
BINNING_INDEX:   1
IM_URL:          sw00345551000msuni0133.fits
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 45"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.60d {+07h 46m 23s}  +22.38d {+22d 22' 59"}
MOON_DIST:       133.49 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [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 07 Mar 09 03:53:09 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.005d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.633d {-28d 37' 57"} (J2000)
POINT_ROLL:      100.816d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13725.93 SOD {03:48:45.93} UT,   128.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.335
N_STARS:         146
X_OFFSET:        392 [pixels]
Y_OFFSET:        695 [pixels]
X_MAX:           1351 [pixels]
Y_MAX:           1654 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00345551000msufc0128.fits
SUN_POSTN:       347.77d {+23h 11m 05s}   -5.25d {-05d 14' 47"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.58d {+07h 46m 19s}  +22.39d {+22d 23' 15"}
MOON_DIST:       133.51 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Mar 09 04:00:40 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.004d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.637d {-28d 38' 11"} (J2000)
POINT_ROLL:      100.820d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13883.89 SOD {03:51:23.89} UT,   286.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.291
N_STARS:         98
X_OFFSET:        152 [pixels]
Y_OFFSET:        455 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1894 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00345551000msufc0286.fits
SUN_POSTN:       347.77d {+23h 11m 06s}   -5.24d {-05d 14' 40"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.66d {+07h 46m 38s}  +22.37d {+22d 22' 03"}
MOON_DIST:       133.43 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 07 Mar 09 04:01:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.004d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.637d {-28d 38' 11"} (J2000)
POINT_ROLL:      100.820d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13883.89 SOD {03:51:23.89} UT,   286.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.291
N_STARS:         98
X_OFFSET:        152 [pixels]
Y_OFFSET:        455 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1894 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00345551000msufc0286.fits
SUN_POSTN:       347.77d {+23h 11m 06s}   -5.24d {-05d 14' 39"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.67d {+07h 46m 40s}  +22.37d {+22d 21' 57"}
MOON_DIST:       133.43 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [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 07 Mar 09 04:02:04 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.004d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.637d {-28d 38' 11"} (J2000)
ROLL:            100.820d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13883.89 SOD {03:51:23.89} UT,   286.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     258090688
X_OFFSET:        711 [pixels]
Y_OFFSET:        1014 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1174
BINNING_INDEX:   1
IM_URL:          sw00345551000msuni0291.fits
SUN_POSTN:       347.78d {+23h 11m 06s}   -5.24d {-05d 14' 38"}
SUN_DIST:         98.47 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.67d {+07h 46m 42s}  +22.36d {+22d 21' 50"}
MOON_DIST:       133.42 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [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 07 Mar 09 04:02:32 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.004d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.637d {-28d 38' 11"} (J2000)
ROLL:            100.820d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13883.89 SOD {03:51:23.89} UT,   286.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     258090688
X_OFFSET:        711 [pixels]
Y_OFFSET:        1014 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       871
Y_GRB_POS:       1174
BINNING_INDEX:   1
IM_URL:          sw00345551000msuni0291.fits
SUN_POSTN:       347.78d {+23h 11m 06s}   -5.24d {-05d 14' 38"}
SUN_DIST:         98.47 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.68d {+07h 46m 43s}  +22.36d {+22d 21' 45"}
MOON_DIST:       133.42 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [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 07 Mar 09 04:00:40 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     345551,   Seg_Num: 0
POINT_RA:        245.004d {+16h 20m 01s} (J2000)
POINT_DEC:       -28.637d {-28d 38' 11"} (J2000)
POINT_ROLL:      100.820d
IMG_START_DATE:  14897 TJD;    66 DOY;   09/03/07
IMG_START_TIME:  13883.89 SOD {03:51:23.89} UT,   286.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.291
N_STARS:         98
X_OFFSET:        152 [pixels]
Y_OFFSET:        455 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1894 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00345551000msufc0286.fits
SUN_POSTN:       347.77d {+23h 11m 06s}   -5.24d {-05d 14' 40"}
SUN_DIST:         98.46 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN:      116.66d {+07h 46m 38s}  +22.37d {+22d 22' 03"}
MOON_DIST:       133.43 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      348.81, 15.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      248.05, -7.08 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #8943
P. A. Evans (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), F. E. Marshall (NASA/GSFC), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC), M. H. Siegel (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 03:46:37 UT, the Swift Burst Alert Telescope (BAT) triggered and located a marginal peak (trigger=345551). Swift slewed immediately to the +location. The BAT on-board calculated location is RA, Dec 244.979, -28.644, which is
```
   RA(J2000)  = 16h 19m 55s
   Dec(J2000) = -28d 38' 38"
```
with an uncertainty of 4 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a slight increase above background at T_0, but it is very weak.
The XRT began observing the field at 03:48:52.38 UT, 135.5 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 244.99412, -28.63366 which is equivalent to:
```
   RA(J2000)  = 16h 19m 58.59s
   Dec(J2000) = -28d 38' 01.2"
```
with an uncertainty of 3.8 arcseconds (radius, 90% containment). The source does not appear to be fading at this time, with a limit of alpha ~0.5.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.14e+21 cm^-2 (Kalberla et al. 2005).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 128 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 XRT 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 0.53.
We are currently commissioning a new sub-threshold capability for Swift, allowing the spacecraft to quickly slew to events with marginal statistics (in the 5.5 - 6.5 sigma range) in the BAT image, and using XRT to test whether a source is detected at a consistent position. If automatic ground processing finds a consistent XRT source, the event is automatically promoted to GRB status, and the original BAT position and other TDRSS messages are released as delayed GCN Notices.
We believe that this event was most likely to be a low-significance statistical fluctuation in the BAT image, in coincidence with a serendipitous detection of a non-GRB astrophysical source by the XRT. After the XRT source was found, GCN Notices were transmitted, 7 minutes after the original trigger.
The association of the initial BAT detection with a real GRB will be determined using Malindi data, including analysis of the XRT data to see if the XRT source exhibits GRB-like temporal and spectral behavior. The currently available XRT data does not indicate fading.
GCN Circular #8945
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), P. A. Evans (U Leicester), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-60 to T+303 sec from recent telemetry downlinks, we report further analysis of posible GRB 090307 (trigger #345551) (Evans, et al., GCN Circ. 8943). The BAT ground-calculated position is RA, Dec = 245.007, -28.647 deg, which is
```
   RA(J2000)  =  16h 20m 01.7s 
   Dec(J2000) = -28d 38' 48.2" 
```
with an uncertainty of 3.3 arcmin, (radius, sys+stat, 90% containment). We note that this position is based on a weak peak in the image domain (5.5 sigma). This is lower than our regular detections because this is a Subthreshold trigger. The partial coding was 87%.
The mask-weighted light curve shows a weak pulse starting at ~T-7 sec and ending at ~T+20 sec. T90 (15-350 keV) is 22 +- 8 sec (estimated error including systematics).
The time-averaged spectrum from T-7.4 to T+16.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.08 +- 0.39. The fluence in the 15-150 keV band is 2.6 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+5.57 sec in the 15-150 keV band is 0.2 +- 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/345551/BA/
Given the weak nature of this event and the as yet unconfirmed nature of this trigger by the XRT follow-up observations, we can not rule out that this trigger is due something other than a GRB. There are further XRT follow-up observations in the observing plan.
GCN Circular #8946
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT observed the field of GRB 090307 (BAT trigger 345551; GCN Circs. 8943, 8945) for 4.6 ks, from 135 s to 80 ks after the BAT trigger. All of the data were taken in Photon Counting (PC) mode. The X-ray source reported by Evans et al. (GCN Circ. 8943) is seen to fade, and is therefore identified as the afterglow, confirming the GRB nature of this BAT trigger. The source has an enhanced XRT position: RA, Dec = 244.9944, -28.6333 which is equivalent to:
```
RA (J2000): 16 19 58.64
Dec (J2000): -28 37 59.9
```
with an uncertainty of 2.1 arcsec (radius, 90% confidence). The light curve shows a power-law decay, with an index 0.7 (+0.2, -0.1).
The PC mode spectrum can be fitted with an absorbed power-law, with a photon index of 2.21 (+0.72, -0.60) and an absorbing column of 3.5 (+2.7,-1.1) e21 cm-2, in excess of the Galactic value of 1.3e21 cm-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10-11 (7.6 x 10-11) erg cm-2 count-1.
If the light curve continues to decay with alpha=0.7, the XRT count-rate at T+48 hrs will be 0.002 counts s-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.38e-14 (1.4e-13) erg cm-2 s-1.
The results of the automatic XRT analysis are available online at http://www.swift.ac.uk/xrt_products/00345551.
This circular is an official product of the Swift-XRT team.
GCN Circular #8959
A. C. Updike (Clemson University), C. Clemens, J. Greiner and P. Afonso (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 090307 (Swift trigger 345551; Barthelmy et al., GCN #8945) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile).
Observations started at 05:06 UT on March 7, 80 min after the GRB trigger, and continued for 66 min. They were performed at an average seeing of 1.2" and at an average airmass of 1.8.
We do not detect a source within the Swift-XRT error circle reported by Evans et al. (GCN #8946) down to (all in AB system)
```
g' > 23.3,
r' > 23.7,
i' > 23.2,
z' > 22.9,
J > 21.7,
H > 21.2 and
K > 20.3.
```
The given limits are derived based on calibrating the images against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.528 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #8974
Klotz, A. (CESR-OMP), Gendre, B. (LAM-OAMP), Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 090307A detected by SWIFT (trigger 345551) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
The observations started 373.3s after the GRB trigger The elevation of the field increased from 16 degrees above horizon and weather conditions were good.
The first image has a duration of 90.0s. We do not detect any OT at the XRT position (Evans GCNC 8946) with a limiting magnitude of: t0+373.3s to t0+463.3s : R > 16.5
We co-added a series of exposures: t0+373.3s to t0+1062.0s : R > 18.9
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon=348.7859 lat=+15.1296 and the galactic extinction in R band is ~1.4 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
GCN Report 199.1
GCN_Report 199.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_199_1.pdf by P.A. Evans at U.Leicester titled: "Final Swift Observations of GRB 090307"

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Jochen Greiner, last update: 13-Mar-2009 [Disclaimer]