Gamma-ray Burst 070224

(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 24 Feb 07 20:29:12 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     261880,   Seg_Num: 0
GRB_RA:          178.990d {+11h 55m 58s} (J2000),
                 179.081d {+11h 56m 19s} (current),
                 178.351d {+11h 53m 24s} (1950)
GRB_DEC:         -13.340d {-13d 20' 23"} (J2000),
                 -13.380d {-13d 22' 46"} (current),
                 -13.062d {-13d 03' 41"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1508 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        14155 TJD;    55 DOY;   07/02/24
GRB_TIME:        73678.21 SOD {20:27:58.21} UT
GRB_PHI:          -0.44 [deg]
GRB_THETA:        12.25 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.50 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -2  +0  +0 +85  +1 
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 58"}
SUN_DIST:        148.85 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.18d {+04h 40m 44s}  +27.53d {+27d 31' 57"}
MOON_DIST:       112.73 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.79, 47.35 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      184.47,-12.62 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 79.57,-16.28 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:30:49 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     261880,   Seg_Num: 0
GRB_RA:          179.0263d {+11h 56m 06.3s} (J2000),
                 179.1178d {+11h 56m 28.2s} (current),
                 178.3873d {+11h 53m 32.9s} (1950)
GRB_DEC:         -13.3303d {-13d 19' 49.0"} (J2000),
                 -13.3701d {-13d 22' 12.3"} (current),
                 -13.0520d {-13d 03' 07.0"} (1950)
GRB_ERROR:       7.2 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       20 [cnts]
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73821.10 SOD {20:30:21.10} UT,   142.9 [sec] since BAT Trigger Time
CENTROID_X:      237.17,  raw= 237  [pixels]
CENTROID_Y:      385.07,  raw= 385  [pixels]
ROLL:            135.90 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   205.26
GRB_POS_XRT_Z:   -153.52
IMAGE_URL:       sw00261880000msxps_rw.img
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 56"}
SUN_DIST:        148.83 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.20d {+04h 40m 48s}  +27.53d {+27d 32' 05"}
MOON_DIST:       112.74 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.84, 47.37 [deg] galactic lon,lat of the burst
ECL_COORDS:      184.50,-12.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:30:55 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     261880,   Seg_Num: 0
GRB_RA:          179.0263d {+11h 56m 06.3s} (J2000),
                 179.1178d {+11h 56m 28.2s} (current),
                 178.3873d {+11h 53m 32.9s} (1950)
GRB_DEC:         -13.3303d {-13d 19' 49.0"} (J2000),
                 -13.3701d {-13d 22' 12.3"} (current),
                 -13.0520d {-13d 03' 07.0"} (1950)
GRB_ERROR:       7.2 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       20 [cnts]
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73821.10 SOD {20:30:21.10} UT,   142.9 [sec] since BAT Trigger Time
CENTROID_X:      237.17,  raw= 237  [pixels]
CENTROID_Y:      385.07,  raw= 385  [pixels]
ROLL:            135.90 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   205.26
GRB_POS_XRT_Z:   -153.52
IMAGE_URL:       sw00261880000msxps_rw.img
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 56"}
SUN_DIST:        148.83 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.20d {+04h 40m 49s}  +27.53d {+27d 32' 05"}
MOON_DIST:       112.74 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.84, 47.37 [deg] galactic lon,lat of the burst
ECL_COORDS:      184.50,-12.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:30:48 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     261880,   Seg_Num: 0
GRB_RA:          179.0263d {+11h 56m 06.3s} (J2000),
                 179.1178d {+11h 56m 28.2s} (current),
                 178.3873d {+11h 53m 32.9s} (1950)
GRB_DEC:         -13.3303d {-13d 19' 49.0"} (J2000),
                 -13.3701d {-13d 22' 12.3"} (current),
                 -13.0520d {-13d 03' 07.0"} (1950)
GRB_ERROR:       7.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       3.07e-10 [erg/cm2/sec]
GRB_SIGNIF:      4.47 [sigma]
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73821.10 SOD {20:30:21.10} UT,   142.9 [sec] since BAT Trigger Time
TAM[0-3]:        327.65 237.16 261.15 243.60
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 57"}
SUN_DIST:        148.83 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.20d {+04h 40m 48s}  +27.53d {+27d 32' 05"}
MOON_DIST:       112.74 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.84, 47.37 [deg] galactic lon,lat of the burst
ECL_COORDS:      184.50,-12.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:31:53 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     261880,   Seg_Num: 0
GRB_RA:          178.990d {+11h 55m 58s} (J2000),
                 179.081d {+11h 56m 19s} (current),
                 178.351d {+11h 53m 24s} (1950)
GRB_DEC:         -13.340d {-13d 20' 23"} (J2000),
                 -13.380d {-13d 22' 46"} (current),
                 -13.062d {-13d 03' 41"} (1950)
GRB_DATE:        14155 TJD;    55 DOY;   07/02/24
GRB_TIME:        73678.21 SOD {20:27:58.21} UT
TRIGGER_INDEX:   20000
GRB_PHI:          -0.44 [deg]
GRB_THETA:        12.25 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.50 [sigma]
LC_URL:          sw00261880000msb.lc
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 55"}
SUN_DIST:        148.85 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.21d {+04h 40m 51s}  +27.54d {+27d 32' 10"}
MOON_DIST:       112.70 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.79, 47.35 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      184.47,-12.62 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is an image trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 79.57,-16.28 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:32:33 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 21"} (J2000)
POINT_ROLL:      135.903d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73830.97 SOD {20:30:30.97} UT,   152.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.618
N_STARS:         59
X_OFFSET:        552 [pixels]
Y_OFFSET:        312 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1271 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0152.fits
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 55"}
SUN_DIST:        148.87 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.22d {+04h 40m 53s}  +27.54d {+27d 32' 13"}
MOON_DIST:       112.66 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:32:58 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 21"} (J2000)
POINT_ROLL:      135.903d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73830.97 SOD {20:30:30.97} UT,   152.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.618
N_STARS:         59
X_OFFSET:        552 [pixels]
Y_OFFSET:        312 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1271 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0152.fits
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.37d {-09d 21' 54"}
SUN_DIST:        148.87 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.22d {+04h 40m 54s}  +27.54d {+27d 32' 15"}
MOON_DIST:       112.66 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.64 [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 24 Feb 07 20:34:42 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 21"} (J2000)
ROLL:            135.903d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73830.97 SOD {20:30:30.97} UT,   152.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     194041832
X_OFFSET:        872 [pixels]
Y_OFFSET:        369 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1032
Y_GRB_POS:       529
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0152.fits
SUN_POSTN:       337.64d {+22h 30m 33s}   -9.36d {-09d 21' 53"}
SUN_DIST:        148.87 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.24d {+04h 40m 58s}  +27.54d {+27d 32' 24"}
MOON_DIST:       112.65 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:34:59 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 21"} (J2000)
ROLL:            135.903d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73830.97 SOD {20:30:30.97} UT,   152.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     194041832
X_OFFSET:        872 [pixels]
Y_OFFSET:        369 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1032
Y_GRB_POS:       529
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0152.fits
SUN_POSTN:       337.64d {+22h 30m 34s}   -9.36d {-09d 21' 53"}
SUN_DIST:        148.87 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.25d {+04h 40m 59s}  +27.54d {+27d 32' 25"}
MOON_DIST:       112.64 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.64 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:40:29 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
POINT_ROLL:      135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73936.23 SOD {20:32:16.23} UT,   258.0 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.514
N_STARS:         89
X_OFFSET:        552 [pixels]
Y_OFFSET:        49 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1008 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0258.fits
SUN_POSTN:       337.64d {+22h 30m 34s}   -9.36d {-09d 21' 48"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.30d {+04h 41m 13s}  +27.55d {+27d 32' 52"}
MOON_DIST:       112.59 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:40:55 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
POINT_ROLL:      135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73936.23 SOD {20:32:16.23} UT,   258.0 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.514
N_STARS:         89
X_OFFSET:        552 [pixels]
Y_OFFSET:        49 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1008 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0258.fits
SUN_POSTN:       337.64d {+22h 30m 34s}   -9.36d {-09d 21' 47"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.31d {+04h 41m 14s}  +27.55d {+27d 32' 54"}
MOON_DIST:       112.59 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [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 24 Feb 07 20:41:42 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
ROLL:            135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73936.23 SOD {20:32:16.23} UT,   258.0 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     194041938
X_OFFSET:        872 [pixels]
Y_OFFSET:        369 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1032
Y_GRB_POS:       529
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0258.fits
SUN_POSTN:       337.64d {+22h 30m 35s}   -9.36d {-09d 21' 46"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.32d {+04h 41m 16s}  +27.55d {+27d 32' 57"}
MOON_DIST:       112.58 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:42:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
ROLL:            135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  73936.23 SOD {20:32:16.23} UT,   258.0 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     194041938
X_OFFSET:        872 [pixels]
Y_OFFSET:        369 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1032
Y_GRB_POS:       529
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0258.fits
SUN_POSTN:       337.64d {+22h 30m 35s}   -9.36d {-09d 21' 46"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.32d {+04h 41m 17s}  +27.55d {+27d 32' 59"}
MOON_DIST:       112.58 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:44:24 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
POINT_ROLL:      135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74539.65 SOD {20:42:19.65} UT,   861.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.563
N_STARS:         84
X_OFFSET:        552 [pixels]
Y_OFFSET:        49 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1008 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0861.fits
SUN_POSTN:       337.65d {+22h 30m 35s}   -9.36d {-09d 21' 44"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.34d {+04h 41m 23s}  +27.55d {+27d 33' 11"}
MOON_DIST:       112.56 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:44:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
POINT_ROLL:      135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74539.65 SOD {20:42:19.65} UT,   861.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.563
N_STARS:         84
X_OFFSET:        552 [pixels]
Y_OFFSET:        49 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1008 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0861.fits
SUN_POSTN:       337.65d {+22h 30m 35s}   -9.36d {-09d 21' 44"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.35d {+04h 41m 24s}  +27.55d {+27d 33' 12"}
MOON_DIST:       112.55 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [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 24 Feb 07 20:45:40 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
ROLL:            135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74539.65 SOD {20:42:19.65} UT,   861.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     194042541
X_OFFSET:        871 [pixels]
Y_OFFSET:        368 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1031
Y_GRB_POS:       528
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0861.fits
SUN_POSTN:       337.65d {+22h 30m 35s}   -9.36d {-09d 21' 43"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.36d {+04h 41m 26s}  +27.55d {+27d 33' 17"}
MOON_DIST:       112.54 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [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 24 Feb 07 20:45:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
ROLL:            135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74539.65 SOD {20:42:19.65} UT,   861.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     194042541
X_OFFSET:        871 [pixels]
Y_OFFSET:        368 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1031
Y_GRB_POS:       528
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0861.fits
SUN_POSTN:       337.65d {+22h 30m 35s}   -9.36d {-09d 21' 43"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.36d {+04h 41m 26s}  +27.55d {+27d 33' 18"}
MOON_DIST:       112.54 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #6137
J. L. Racusin (PSU), L. M. Barbier (NASA/GSFC), S. D. Barthelmy (GSFC), M. M. Chester (PSU), G. Cusumano (INAF-IASFPA), D. Grupe (PSU), J. A. Kennea (PSU), D. M. Palmer (LANL), R. L. C. Starling (U Leicester) and L. Vetere (PSU) report on behalf of the Swift Team:
At 20:27:58 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 070224 (trigger=261880). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 178.990, -13.340 which is
```
   RA(J2000)  =  11h 55m 58s
   Dec(J2000) = -13d 20' 23"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 25 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 20:30:21 UT, 143 seconds after the BAT trigger. XRT found a bright, fading, uncatalogued X-ray source located at RA, Dec 179.0257, -13.3294 which is
```
   RA(J2000)  =  11h 56m 06.2s
   Dec(J2000) = -13d 19' 46.0"
```
with an uncertainty of 4.2 arcseconds (radius, 90% containment). This location is 131 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 2.5s image was 3.1e-10 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 153 seconds after the BAT trigger, and a finding chart of nominal 400 seconds with the V filter starting 259 seconds after the BAT trigger. No 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 3-sigma upper limit in White at the XRT position is 19.3 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. No correction has been made for the expected extinction corresponding to E(B-V) of 0.06.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:51:03 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
POINT_ROLL:      135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74644.87 SOD {20:44:04.87} UT,   966.7 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.524
N_STARS:         91
X_OFFSET:        552 [pixels]
Y_OFFSET:        49 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1008 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0966.fits
SUN_POSTN:       337.65d {+22h 30m 36s}   -9.36d {-09d 21' 38"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.41d {+04h 41m 39s}  +27.56d {+27d 33' 43"}
MOON_DIST:       112.49 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 24 Feb 07 20:51:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
POINT_ROLL:      135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74644.87 SOD {20:44:04.87} UT,   966.7 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.524
N_STARS:         91
X_OFFSET:        552 [pixels]
Y_OFFSET:        49 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1008 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00261880000msufc0966.fits
SUN_POSTN:       337.65d {+22h 30m 36s}   -9.36d {-09d 21' 37"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.42d {+04h 41m 40s}  +27.56d {+27d 33' 45"}
MOON_DIST:       112.49 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [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 24 Feb 07 20:52:18 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
ROLL:            135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74644.87 SOD {20:44:04.87} UT,   966.7 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     194042646
X_OFFSET:        871 [pixels]
Y_OFFSET:        368 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1031
Y_GRB_POS:       528
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0966.fits
SUN_POSTN:       337.65d {+22h 30m 36s}   -9.36d {-09d 21' 37"}
SUN_DIST:        148.88 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.43d {+04h 41m 43s}  +27.56d {+27d 33' 49"}
MOON_DIST:       112.48 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [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 24 Feb 07 20:52:32 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     261880,   Seg_Num: 0
POINT_RA:        178.954d {+11h 55m 49s} (J2000)
POINT_DEC:       -13.339d {-13d 20' 18"} (J2000)
ROLL:            135.900d
IMG_START_DATE:  14155 TJD;    55 DOY;   07/02/24
IMG_START_TIME:  74644.87 SOD {20:44:04.87} UT,   966.7 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     194042646
X_OFFSET:        871 [pixels]
Y_OFFSET:        368 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1031
Y_GRB_POS:       528
BINNING_INDEX:   1
IM_URL:          sw00261880000msuni0966.fits
SUN_POSTN:       337.65d {+22h 30m 36s}   -9.36d {-09d 21' 36"}
SUN_DIST:        148.89 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       70.43d {+04h 41m 43s}  +27.56d {+27d 33' 50"}
MOON_DIST:       112.48 [deg]
MOON_ILLUM:      56 [%]
GAL_COORDS:      282.75, 47.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      184.44,-12.63 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #6138
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy, A.Krylov,N.Shatskiy ,G.Borisov, A.Sankovich, G.Antipov, V.Vladimirov P.Gritsyk
Sternberg Astronomical Institute, Moscow Union 'Optic' MASTER robotic system (http://observ.pereplet.ru) responded to GRB070224.9 (GRB_TIME is 2007-02-24 20:27:58.21). The first image was at 2007-02-24 20:30:04 UT, 51s after notice arrivel time and 00:02:05.79 after the GRB time The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B). The robot not find OT-candidate in error box brighter then 16.2 (s/n=10). The JPG-image will be available at http://observ.pereplet.ru/images/GRB070224.9/img/i12.jpg The reduction is continuing. This message can be cited. Mailto: lipunov@sai.msu.ru
GCN Circular #6139
V. Lipunov, V.Kornilov, N.Shatskiy, E.Gorbovskoy, A.Belinski, D.Kuvshinov, N.Tyurina, P.Gritsyk Sternberg Astronomical Institute, Moscow Union 'Optic'
A. Tlatov, I.Golubov Kislovodsk Solar Station of the Pulkovo observatory
MASTER Very Wide Field Camera located at Kislovodsk Solar Station (http://observ.pereplet.ru, D=70 mm, 420 square degrees, 11 Mpixel's CCD) has moved to the Swift-BAT trigger 261880 and it has taken a series of 5s exposures starting 2 s after notice arrivel time at 20:29:38.285 UT under good weather condition and waxing moon.
We note that the GBR position (J. L. Racusin et al. GCN Circ No. 6137) was at 4 degrees outside of the our field of view.
We note that the VWF camera continuously takes frames during the night.
These unfiltered images are calibrated relative to USNO A2.0 (R). There is no OT was found inside Swift error box.
```
T-Tgrb     Mean Time     Limit   Coadd?

29s        29.5s        11.0     no

29s        59 s         12.0     12
```
The message can be cited.
mailto: lipunov@sai.msu.ru
GCN Circular #6140
V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, E.Gorbovskoy, A.Krylov, N.Shatskiy, N.Tyurina,G.Borisov, A.Sankovich, V.Vladimirov, V.Vibornov, A.Kuznetsov Sternberg Astronomical Institute, Moscow Union 'Optic'
A. Tlatov, I.Golubov Kislovodsk Solar Station of the Pulkovo observatory
MASTER Very Wide Field Camera located at Kislovodsk Solar Station (http://observ.pereplet.ru, D=70 mm, 420 square degrees, 11 Mpixel's CCD) has moved to the Swift-BAT trigger 261880 and it has taken a series of 5s exposures starting 2 s after notice arrivel time at 20:29:38.285 UT under good weather condition and waxing moon.
We note that the GBR position (J. L. Racusin et al. GCN Circ No. 6137) was at 4 degrees outside of the our field of view.
We note that the VWF camera continuously takes frames during the night. These unfiltered images are calibrated relative to USNO A2.0 (R). The robot not find OT-candidate.
```
T-Tgrb     Mean Time     Limit   Coadd?   Exp

100s        100.5s        11.0     no      5s
100s        130 s         12.0     yes   12x5s
100s        222 s         13.3     yes   47x5s
```
MASTER robotic system (D=355mm, http://observ.pereplet.ru, Moscow) responded to GRB070224 (GRB_TIME is 2007-02-24 20:27:58.21). The first image was at 2007-02-24 20:30:04 UT, 51s after notice arrivel time and 00:02:05.79 after the GRB time at large zenit distance. The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B). The robot not find OT-candidate.
```
T-Tgrb     Mean Time     Limit   Coadd?  Exp

125s        140s         16.2     no     30s
125s        924s         18.0    yes     31x30s
```
This message can be cited. Mailto: lipunov@sai.msu.ru
GCN Circular #6141
J. Tueller (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), J. L. Racusin (PSU), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU) on behalf of the Swift-BAT team:
Using the data set from T-239 to T+482 sec from the recent telemetry downlink, we report further analysis of BAT GRB 070224 (trigger #261880) (Racusin, et al., GCN Circ. 6137). The BAT ground-calculated position is RA, Dec = 178.987, -13.356 deg which is
```
   RA(J2000)  =  11h 55m 57.0s 
   Dec(J2000) = -13d 21' 20.1" 
```
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted lightcurve shows two overlapping peaks starting at ~T-20 sec and decaying back to background at ~T+50 sec. T90 (15-350 keV) is 34 +- 1 sec (estimated error including systematics).
The time-averaged spectrum from T-13.8 to T+24.3 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.42 +- 0.30. The fluence in the 15-150 keV band is 3.1 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-13.76 sec in the 15-150 keV band is 0.3 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #6142
Christina C. Thoene (DARK), D. Alexander Kann (TLS Tautenburg) and Thomas Augusteijn (NOT) report:
We observed the field of GRB 070224 (GCN 6137) with NOT and StanCAM in R and I filters starting 4.35h after the burst.
In 3x300s stacked images, we detect a faint object in both R and I close to the XRT error circle at
```
RA = 11:56:06.68
Dec = -13:19:47.6 (J2000)
```
with conservative errors of 1". This is about 5 arcseconds from the refined XRT error circle center (GCN 6143).
We propose this object to be the optical afterglow of GRB 070224. At the moment, we cannot confirm if the object is fading or not. Further observations are planned.
GCN Circular #6143
J. Racusin, J. Kennea, D. Morris, C. Pagani, L. Vetere (PSU) report on behalf of the Swift-XRT team:
We have analysed the first 3 orbits of Swift-XRT data available for GRB 070224 (Racusin et al., GCN 6137), consisting of 45 s of Windowed Timing (WT) mode data, and ~1.7 ks of Photon Counting (PC) mode data. The refined XRT position from the PC data is RA,Dec= 179.02684, -13.3304 which is:
```
RA(J2000)  = 11h 56m 06.44s
Dec(J2000) = -13d 19' 49.5"
```
with an uncertainty of 3.8 arcsec (90% containment). This is 5.0 arcseconds from the initial position reported in GCN 6137, and 134 arcseconds from the BAT refined position (Tueller et al., GCN 6141).
The preliminary 0.3-10.0 keV lightcurve shows a steep fading behavior in the first orbit with a decay index of 3.1 +/- 0.2. The data in the subsequent orbits provides only an upper limit. It is not currently possible to determine if there has been a break to a flatter decay.
The WT spectrum is fit by an absorbed power-law with a photon index of 2.8 +/- 0.6. The absorption is at a level of 6.0e20 cm^-2, consistent with Galactic absorption along the line of sight (4.1e20 cm^-2). The average 0.3-10 keV unabsorbed flux of the WT spectrum is 2.1e-10 ergs cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular #6144
A. C. Updike, H. A. Eid, D. H. Hartmann (Clemson University), T. H. Robertson, T. M. Jordan (Ball State University), and D. A. Kann (TLS) report on behalf of the Clemson GRB Follow-Up Team:
The .9m SARA telescope began imaging the field of GRB 070224 approximately 9 hours after the Swift Trigger 261880 at 20:29:12 UT. Our observations were comprised of 180-second exposures in the R band. After stacking 2 hours worth of exposures, we do not detect any new sources down to a limiting magnitude of R ~ 21.4 +/- 0.4 mag (based on calibration to 10 field sources from USNO B1.0 R2 band).
The Clemson University GRB Response Site may be found at: http://people.clemson.edu/~kgarime/burst/index.php
The SARA Homepage can be found at: http://saraobservatory.org
This message may be cited.
GCN Circular #6145
H.-W. Chen (U Chicago), K. Glazebrook (Swinburne University), and J. S. Bloom (UC Berkeley) report on behalf of a larger collaboration:
"We obtained 2x900 sec dithered exposures of the field around GRB070224 (Racusin et al., GCN 6137), using GMOS and an i' filter on the Gemini south telescope. The observations started at Feb 25.102 UT, ~ 6 hours after the initial Swift trigger. We continued the observations with 2x900 sec dithered exposures in the z'-band, starting at Feb 25.125 UT. Within the refined XRT position (Racusin et al., GCN 6143), we detect a compact source at RA(J2000)=11:56:06.6 and Dec(J2000)=-13:19:48.9 (+/- 350 mas relative to USNO B1.0) that shows no apparent changes in the brightness between two exposures of 15 min apart. We note the presence of extremely faint (~2 sigma) source at RA(J2000)=11:56:06.5 and Dec(J2000)=-13:19:49.9 in the first i'-band exposure. Further analysis is underway."
GCN Circular #6146
N. Mirabal, K. Stanonik, N. Zimmerman, S. Alayyoubi, & J. P. Halpern (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team:
"We observed the field of GRB 070224 (Racusin et al., GCNs 6137, 6143) in I-band with the MDM 1.3m telescope. The object reported by Thoene et al. (GCN 6142) is present in our images, with a preliminary magnitude I~22.1 +/- 0.2 on Feb. 25.287."
GCN Circular #6147
E. Rol, N.R. Tanvir, R. Starling (U. Leicester) and P. Groot (U. Nijmegen) report on behalf of a larger collaboration:
We observed the field of GRB 070224 with the WHT/LIRIS instrument in poor seeing, beginning at Feb 24 23:06 UT. Our 6 minute K-band image reached a 3-sigma limit of K~19.2 (based on calibration via four 2MASS stars in the field).
A later observation in better seeing, beginning at Feb 25 04:44 UT, reached a limiting magnitude of K~19.7.
In both images within the XRT error circle (GCN 6143) we see a source at the position of the candidate reported by Thoene et al. (GCN 6142), with a magnitude that is consistent with K~19.2 in both cases, although some fading can't be ruled out.
In the second image we also see (close to the limit) another source with (2000) coordinates approximately:
11 56 06.26 -13 19 50.0
GCN Circular #6148
H.-W. Chen (U Chicago), K. Glazebrook (Swinburne University), and J. S. Bloom (UC Berkeley) report on behalf of a larger collaboration:
"We continued imaging observations of the field around GRB 070224 (Racusin et al., GCN 6137), using MagIC on the Magellan Clay telescope. The observations consisted of 5x300 sec dithered exposures in the i' band and 6x600 sec dithered exposures in the z' band, starting at Feb 25.180 UT, ~ 8 hours after the initial Swift trigger. The images were taken under photometric conditions with a mean seeing of 0.5" in i' and 0.6" in z'. Object photometry was calibrated using a Sloan Digital Sky Survey photometric standard observed after the GRB field. Combining the images obtained using GMOS and MagIC, we measure photometry of the compact source at RA(J2000)=11:56:06.6 and Dec(J2000)=-13:19:48.9 (Chen, Glazebrook, & Bloom, GCN 6145; see also Thoene et al. GCN 6142, Mirabal et al. GCN 6146, Rol et al. GCN 6147) as the following:
```
   Filter         AB      UT(mid)         Camera

     i'    22.60 +/- 0.10  25.107          GMOS
     z'    22.40 +/- 0.20  25.135          GMOS
     i'    22.54 +/- 0.05  25.188         MagIC
     z'    22.56 +/- 0.05  25.221         MagIC
```
We therefore conclude that this is not a variable source.
The source at RA(J2000)=11:56:06.5 and Dec(J2000)=-13:19:49.9 that appeared at low level in the first GMOS i'-band image (Chen, Glazebrook, & Bloom GCN 6145) remains absent in the MagIC images."
GCN Circular #6151
J. Racusin (PSU), M. Goad (U. Leicester), D.N. Burrows (PSU), O. Godet (U. Leicester), R. Starling (U. Leicester) report on behalf of the Swift XRT team:
Based on an accurate mapping between the XRT and UVOT detector coordinate systems, we have used the simultaneous UVOT V-band images to astrometrically correct (relative to stellar catalogues, e.g. USNO-B1) the XRT world coordinate system, and thereby refine the XRT position. We obtain a new XRT position at RA,Dec=179.02792,-13.3304 which is:
```
RA(J2000):  11h 56m 06.7s
Dec(J2000): -13d 19' 49.6"
```
with an uncertainty of 2.6 arcseconds (90% containment). This is 3.8 arcseconds from the refined XRT position (Racusin et al., GCN 6143), and 2.0 arcseconds from the optical candidate first identified by Thoene et al. (GCN 6142).
This circular is an official product of the Swift-XRT team.

GCN Circular #6152
S. T. Holland (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC), M. M. Chester (PSU) and J. L. Racusin (PSU) report on the behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 070224 starting 132 s after the BAT trigger (Racusin et al. 2007, GCN Circ. 6137). We do not find any source, in any of the UVOT observations, inside the astrometrically corrected XRT error circle (Racusin et al., 2007 GCN Circ. 6151).
The 3-sigma upper limits for detecting a source anywhere inside the XRT error circle in the finding chart images, and the co-added exposures are:

Filter     T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
White Finding  156      254      96       20.4
V Finding      259      659     393       20.1

    V           259     1367     806       20.5
    B           737      747      10       18.6
    U           713      733      19       18.7
  UVW1          689     5512     132       20.0
  UVM2          665      833      39       18.3
  UVW2          766      785      19       18.2
  White         154      962     206       20.9

    V        35,712  126,303    1553       20.9
    B          7159  128,636    1987       22.0
    U          6954   93,932    1952       21.7
  UVW1         6750  145,987    4321       22.2
  UVM2       12,574  143,883    4621       22.4
  UVW2       29,833  122,852    4358       22.6
-------------------------------------------------------------

The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.06 mag towards the direction of the burst (Schlegel et al. 1998).

GCN Report 36.1
GCN_Report 36.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_36_1.pdf by J.L. Racusin at PSU titled: "Swift Observations on GRB 070224"
GCN Circular #6154
Christina C. Thoene (Dark/NBI), D. Alexander Kann (TLS Tautenburg), Thomas Augusteijn (NOT) and Celine Reyle-Laffont (Observatoire de Besancon) report:
We observed the OT candidate (Thoene et al., GCN 6142) of GRB 070224 (Racusin et al., GCN 6137) again on Feb. 27 (2.27 days after the burst) with NOT and StanCam in R.
The proposed candidate (Thoene et al., GCN 6142, see also Chen et al., GCN 6145, Mirabal et al., GCN 6146, Rol et al., GCN 6147 and Chen et al., GCN 6148) is clearly fading between our three epochs.
We get the following magnitudes:
```
t after burst=A0=A0 exptime=A0=A0 R mag:
0.20 d    900s  22.1 +- 0.2
0.39 d   1800s  22.5 +- 0.2
2.27 d   2400s  24.1 +- 0.3
```
based on two nearby USNO-B1.0 stars.
We therefore conclude that this object is the afterglow of GRB 070224. It thus may have had an early plateau phase (Rol et al., GCN 6147, Chen et al., GCN 6148).
Improved astrometry gives a refined position of the afterglow at (J2000):
```
RA =3D 11:56:06.65 
Dec =3D -13:19:48.8
```
with an error of 0.5 arcsec.
This is 1.1 arcsec from the center of the revised XRT error circle (Racusin et al., GCN Report 36.1) and 0.8 arcsec from the center of Nat Butler's error circle (v2.5) (http://astro.berkeley.edu/~nat/swift/xrt_pos.html).
GCN Circular #6164
Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward GRB 070224 (GCN 6137) at a frequency of 8.46 GHz on 2007 February 28 at 9.99 UT. The GRB is undetected and the peak radio flux at the SWIFT-XRT position (GCN 6143) is -83 uJy =B1 47 uJy.=20
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Report 36.2
GCN_Report 36.2 has been posted: http://gcn.gsfc.nasa.gov/reports/report_36_2.pdf by J.L. Racusin at PSU titled: "Final Swift Observations of GRB 070224"
arXiv:1505.06743 X-shooter redshift: 1.9922

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