Gamma-ray Burst 061121

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:22:42 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     239899,   Seg_Num: 0
GRB_RA:          147.252d {+09h 49m 00s} (J2000),
                 147.335d {+09h 49m 20s} (current),
                 146.646d {+09h 46m 35s} (1950)
GRB_DEC:         -13.183d {-13d 10' 57"} (J2000),
                 -13.215d {-13d 12' 53"} (current),
                 -12.949d {-12d 56' 57"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1423 [cnts]    Image_Peak=110 [image_cnts]
TRIGGER_DUR:     0.256 [sec] 
TRIGGER_INDEX:   123     E_range: 25-100 keV
BKG_INTEN:       28347 [cnts]
BKG_TIME:        55334.41 SOD {15:22:14.41} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14060 TJD;   325 DOY;   06/11/21
GRB_TIME:        55349.00 SOD {15:22:29.00} UT
GRB_PHI:         166.28 [deg]
GRB_THETA:         8.99 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.79 [sigma]
IMAGE_SIGNIF:    8.08 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2 +13  +0  +0  -8  +1 
SUN_POSTN:       236.96d {+15h 47m 50s}  -19.97d {-19d 58' 18"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.87d {+16h 19m 29s}  -26.33d {-26d 19' 32"}
MOON_DIST:        90.75 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.36, 30.15 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      154.39,-24.76 [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 = 192.63,-14.17 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:24:05 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     239899,   Seg_Num: 0
GRB_RA:          147.2263d {+09h 48m 54.3s} (J2000),
                 147.3097d {+09h 49m 14.3s} (current),
                 146.6211d {+09h 46m 29.0s} (1950)
GRB_DEC:         -13.1961d {-13d 11' 45.9"} (J2000),
                 -13.2284d {-13d 13' 42.1"} (current),
                 -12.9628d {-12d 57' 46.1"} (1950)
GRB_ERROR:       4.3 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       341 [cnts]
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55404.40 SOD {15:23:24.40} UT,   55.4 [sec] since BAT Trigger Time
CENTROID_X:      340.44,  raw= 340  [pixels]
CENTROID_Y:      261.02,  raw= 261  [pixels]
ROLL:            109.42 [deg]
GAIN:            8
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -89.05
GRB_POS_XRT_Z:   92.28
IMAGE_URL:       sw00239899000msxps_rw.img
SUN_POSTN:       236.96d {+15h 47m 50s}  -19.97d {-19d 58' 19"}
SUN_DIST:         85.20 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.88d {+16h 19m 32s}  -26.33d {-26d 19' 41"}
MOON_DIST:        90.77 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.36, 30.12 [deg] galactic lon,lat of the burst
ECL_COORDS:      154.37,-24.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:25:34 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.181d {-13d 10' 52"} (J2000)
POINT_ROLL:      109.416d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55410.83 SOD {15:23:30.83} UT,   61.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.744
N_STARS:         38
X_OFFSET:        432 [pixels]
Y_OFFSET:        592 [pixels]
X_MAX:           1391 [pixels]
Y_MAX:           1551 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00239899000msufc0061.fits
SUN_POSTN:       236.96d {+15h 47m 51s}  -19.97d {-19d 58' 19"}
SUN_DIST:         85.17 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.90d {+16h 19m 35s}  -26.33d {-26d 19' 50"}
MOON_DIST:        90.76 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:26:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.181d {-13d 10' 52"} (J2000)
POINT_ROLL:      109.416d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55410.83 SOD {15:23:30.83} UT,   61.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.744
N_STARS:         38
X_OFFSET:        432 [pixels]
Y_OFFSET:        592 [pixels]
X_MAX:           1391 [pixels]
Y_MAX:           1551 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00239899000msufc0061.fits
SUN_POSTN:       236.96d {+15h 47m 51s}  -19.97d {-19d 58' 20"}
SUN_DIST:         85.17 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.90d {+16h 19m 36s}  -26.33d {-26d 19' 53"}
MOON_DIST:        90.77 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:24:04 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     239899,   Seg_Num: 0
GRB_RA:          147.2263d {+09h 48m 54.3s} (J2000),
                 147.3097d {+09h 49m 14.3s} (current),
                 146.6211d {+09h 46m 29.0s} (1950)
GRB_DEC:         -13.1961d {-13d 11' 45.9"} (J2000),
                 -13.2284d {-13d 13' 42.1"} (current),
                 -12.9628d {-12d 57' 46.1"} (1950)
GRB_ERROR:       4.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.84e-08 [erg/cm2/sec]
GRB_SIGNIF:      18.46 [sigma]
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55404.40 SOD {15:23:24.40} UT,   55.4 [sec] since BAT Trigger Time
TAM[0-3]:        327.63 237.20 261.34 243.56
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       236.96d {+15h 47m 50s}  -19.97d {-19d 58' 19"}
SUN_DIST:         85.20 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.88d {+16h 19m 32s}  -26.33d {-26d 19' 41"}
MOON_DIST:        90.77 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.36, 30.12 [deg] galactic lon,lat of the burst
ECL_COORDS:      154.37,-24.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact; see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:26:50 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.181d {-13d 10' 52"} (J2000)
ROLL:            109.416d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55410.83 SOD {15:23:30.83} UT,   61.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     185815412
X_OFFSET:        710 [pixels]
Y_OFFSET:        1110 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       870
Y_GRB_POS:       1270
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0061.fits
SUN_POSTN:       236.96d {+15h 47m 51s}  -19.97d {-19d 58' 20"}
SUN_DIST:         85.17 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.91d {+16h 19m 38s}  -26.33d {-26d 19' 58"}
MOON_DIST:        90.77 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:26:58 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     239899,   Seg_Num: 0
GRB_RA:          147.252d {+09h 49m 00s} (J2000),
                 147.335d {+09h 49m 20s} (current),
                 146.646d {+09h 46m 35s} (1950)
GRB_DEC:         -13.183d {-13d 10' 57"} (J2000),
                 -13.215d {-13d 12' 53"} (current),
                 -12.949d {-12d 56' 57"} (1950)
GRB_DATE:        14060 TJD;   325 DOY;   06/11/21
GRB_TIME:        55349.00 SOD {15:22:29.00} UT
TRIGGER_INDEX:   123
GRB_PHI:         166.28 [deg]
GRB_THETA:         8.99 [deg]
DELTA_TIME:      -18.00 [sec]
TRIGGER_DUR:     0.256 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.79 [sigma]
IMAGE_SIGNIF:    8.08 [sigma]
LC_URL:          sw00239899000msb.lc
SUN_POSTN:       236.96d {+15h 47m 51s}  -19.97d {-19d 58' 20"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.91d {+16h 19m 38s}  -26.33d {-26d 19' 58"}
MOON_DIST:        90.78 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.36, 30.15 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      154.39,-24.76 [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 = 192.63,-14.17 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:27:12 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.181d {-13d 10' 52"} (J2000)
ROLL:            109.416d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55410.83 SOD {15:23:30.83} UT,   61.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     185815412
X_OFFSET:        710 [pixels]
Y_OFFSET:        1110 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       870
Y_GRB_POS:       1270
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0061.fits
SUN_POSTN:       236.96d {+15h 47m 51s}  -19.97d {-19d 58' 20"}
SUN_DIST:         85.17 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.91d {+16h 19m 39s}  -26.33d {-26d 20' 00"}
MOON_DIST:        90.78 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:34:02 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
ROLL:            109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55516.10 SOD {15:25:16.10} UT,   167.1 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     185815517
X_OFFSET:        710 [pixels]
Y_OFFSET:        1110 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       870
Y_GRB_POS:       1270
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0167.fits
SUN_POSTN:       236.97d {+15h 47m 52s}  -19.97d {-19d 58' 24"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.98d {+16h 19m 55s}  -26.35d {-26d 20' 42"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:34:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
ROLL:            109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55516.10 SOD {15:25:16.10} UT,   167.1 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     185815517
X_OFFSET:        710 [pixels]
Y_OFFSET:        1110 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       870
Y_GRB_POS:       1270
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0167.fits
SUN_POSTN:       236.97d {+15h 47m 52s}  -19.97d {-19d 58' 24"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.98d {+16h 19m 56s}  -26.35d {-26d 20' 44"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:38:33 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     239899,   Seg_Num: 0
GRB_RA:          147.2273d {+09h 48m 54.55s} (J2000),
                 147.3107d {+09h 49m 14.56s} (current),
                 146.6221d {+09h 46m 29.29s} (1950)
GRB_DEC:         -13.1951d {-13d 11' 42.3"} (J2000),
                 -13.2274d {-13d 13' 38.5"} (current),
                 -12.9618d {-12d 57' 42.5"} (1950)
GRB_ERROR:       0.4 [arcsec radius, statistical only]
GRB_MAG:         17.20 +/- 0.50 [mag]
FILTER:          3, V
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55516.00 SOD {15:25:16.00} UT,   167.0 [sec] since BAT Trigger Time
SUN_POSTN:       236.97d {+15h 47m 53s}  -19.97d {-19d 58' 27"}
SUN_DIST:         85.20 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.02d {+16h 20m 05s}  -26.35d {-26d 21' 10"}
MOON_DIST:        90.89 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.36, 30.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      154.37,-24.78 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:38:59 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
POINT_ROLL:      109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56220.40 SOD {15:37:00.40} UT,   871.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.998
N_STARS:         38
X_OFFSET:        390 [pixels]
Y_OFFSET:        790 [pixels]
X_MAX:           1349 [pixels]
Y_MAX:           1749 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00239899000msufc0871.fits
SUN_POSTN:       236.97d {+15h 47m 53s}  -19.97d {-19d 58' 27"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.03d {+16h 20m 06s}  -26.35d {-26d 21' 12"}
MOON_DIST:        90.87 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:24:08 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     239899,   Seg_Num: 0
GRB_RA:          147.2263d {+09h 48m 54.3s} (J2000),
                 147.3097d {+09h 49m 14.3s} (current),
                 146.6211d {+09h 46m 29.0s} (1950)
GRB_DEC:         -13.1961d {-13d 11' 45.9"} (J2000),
                 -13.2284d {-13d 13' 42.1"} (current),
                 -12.9628d {-12d 57' 46.1"} (1950)
GRB_ERROR:       4.3 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       341 [cnts]
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55404.40 SOD {15:23:24.40} UT,   55.4 [sec] since BAT Trigger Time
CENTROID_X:      340.44,  raw= 340  [pixels]
CENTROID_Y:      261.02,  raw= 261  [pixels]
ROLL:            109.42 [deg]
GAIN:            8
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -89.05
GRB_POS_XRT_Z:   92.28
IMAGE_URL:       sw00239899000msxps_rw.img
SUN_POSTN:       236.96d {+15h 47m 50s}  -19.97d {-19d 58' 19"}
SUN_DIST:         85.20 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.88d {+16h 19m 32s}  -26.33d {-26d 19' 41"}
MOON_DIST:        90.77 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.36, 30.12 [deg] galactic lon,lat of the burst
ECL_COORDS:      154.37,-24.78 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:46:11 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.259d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 11' 00"} (J2000)
POINT_ROLL:      109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56325.64 SOD {15:38:45.64} UT,   976.6 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        2.574
N_STARS:         38
X_OFFSET:        390 [pixels]
Y_OFFSET:        790 [pixels]
X_MAX:           1349 [pixels]
Y_MAX:           1749 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00239899000msufc0976.fits
SUN_POSTN:       236.98d {+15h 47m 54s}  -19.98d {-19d 58' 31"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.09d {+16h 20m 23s}  -26.37d {-26d 21' 57"}
MOON_DIST:        90.92 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:40:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
ROLL:            109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56220.40 SOD {15:37:00.40} UT,   871.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     185816221
X_OFFSET:        709 [pixels]
Y_OFFSET:        1109 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       869
Y_GRB_POS:       1269
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0871.fits
SUN_POSTN:       236.97d {+15h 47m 53s}  -19.97d {-19d 58' 28"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.04d {+16h 20m 10s}  -26.36d {-26d 21' 23"}
MOON_DIST:        90.88 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:47:15 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.259d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 11' 00"} (J2000)
ROLL:            109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56325.64 SOD {15:38:45.64} UT,   976.6 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     185816327
X_OFFSET:        709 [pixels]
Y_OFFSET:        1109 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       869
Y_GRB_POS:       1269
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0976.fits
SUN_POSTN:       236.98d {+15h 47m 54s}  -19.98d {-19d 58' 31"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.11d {+16h 20m 25s}  -26.37d {-26d 22' 03"}
MOON_DIST:        90.93 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:32:48 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
POINT_ROLL:      109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55516.10 SOD {15:25:16.10} UT,   167.1 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.676
N_STARS:         44
X_OFFSET:        390 [pixels]
Y_OFFSET:        790 [pixels]
X_MAX:           1349 [pixels]
Y_MAX:           1749 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00239899000msufc0167.fits
SUN_POSTN:       236.97d {+15h 47m 52s}  -19.97d {-19d 58' 23"}
SUN_DIST:         85.17 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.97d {+16h 19m 52s}  -26.34d {-26d 20' 34"}
MOON_DIST:        90.82 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:45:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.259d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 11' 00"} (J2000)
POINT_ROLL:      109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56325.64 SOD {15:38:45.64} UT,   976.6 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        2.574
N_STARS:         38
X_OFFSET:        390 [pixels]
Y_OFFSET:        790 [pixels]
X_MAX:           1349 [pixels]
Y_MAX:           1749 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00239899000msufc0976.fits
SUN_POSTN:       236.98d {+15h 47m 54s}  -19.98d {-19d 58' 30"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.09d {+16h 20m 22s}  -26.37d {-26d 21' 54"}
MOON_DIST:        90.92 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #5823
K. L. Page (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), P. J. Brown (PSU), D. N. Burrows (PSU), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Guidorzi (Univ Bicocca&INAF-OAB), J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), W. L. Landsman (NASA/GSFC), V. Mangano (INAF-IASFPA), F. E. Marshall (NASA/GSFC), J. P. Osborne (U Leicester), C. Pagani (PSU), D. M. Palmer (LANL), M. Perri (ASDC), P. Romano (Univ. Bicocca & INAF-OAB), T. Sakamoto (NASA/ORAU), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), E. Troja (INAF-IASFPA), D. E. Vanden Berk (PSU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 15:22:29 UT, the Swift Burst Alert T:lescope (BAT) triggered and located GRB 061121 (trigger=239899). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 147.252, -13.183 {09h 49m 00s, -13d 10' 57"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows an initial pulse of ~3000 cnts/sec lasting ~10 sec. Then a second much brighter peak starts at ~T+50 sec, peaking at T+70 sec (at 32,000 cnts/sec), and ending at ~T+80 sec.
The XRT began observing the field at 15:23:24 UT, 55 seconds after the BAT trigger. XRT found a very bright, fading, uncatalogued X-ray source, located at
```
RA(J2000) = 09h 48m 54.5s,
Dec(J2000) = -13d 11' 46.4"
```
with an estimated uncertainty of 4.7 arcseconds (90% confidence radius). This is a ground calculated position based on prompt downlinked data. This location is 102 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 2.5s image was 1.8e-08 erg/cm2/s (0.2-10 keV). There is a large flare peaking at about 70 s after the BAT trigger.
UVOT took a finding chart exposure of 526 seconds with the V filter starting 167 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =  09:48:54.58 = 147.2274
  DEC(J2000) = -13:11:42.7  = -13.1952
```
with a 1-sigma error radius of about 0.5 arc sec. This position is 5.0 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.2 with a 1-sigma error of about 0.5 mag. No correction has been made for the expected extinction of about 0.1 magnitudes.
We note that the BAT triggered on a precursor allowing the XRT and UVOT to observe during the main emission of the burst.
GCN Circular #5824
S.A. Yost (U Mich), B. E. Schaefer (Louisiana State), F. Yuan (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB 061121 (Swift trigger 239899). The first image was at 15:22:49.6 UT, 20.6 s after the burst (7.6 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 14.9 magnitude, fading source with coordinates:
```
      09:48:54.4      -13:11:42.2    (J2000), with positional 
```
uncertainty of 1" or better.
This is coincident with the UVOT source (GCN 5823)
```
start UT    	mag     mlim(of image)
----------------------------------
15:23:46.2     14.9     14.9
```
A jpeg image is available at http://www.rotse.net/images/gsb239899_3a02_img.jpg Note that the object marked 65 is the candidate in question.
Continuing observations are in progress.
GCN Circular #5825
D. A. Perley and J. S. Bloom report,
On the night of 21 November 2006 (UT), we began spectroscopic observations of GRB061121 at 15:35 UT using Keck I (+LRIS). The optical afterglow is visible in the finder camera in early twilight and is detected in 120-second spectroscopic exposures down to the atmospheric cutoff. Strong absorption features are observed. Observations are continuing.
GCN Circular #5826
J. S. Bloom, D. A. Perley (UC Berkeley) and H.W. Chen (Chicago) report,
"Following the detection of the optical afterglow (GCN 5823, GCN 5824, GCN 5825), we obtained approximately 8 spectroscopic exposures of 120-180 seconds each, beginning at ~15:36 UT with the Keck I 10m telescope + LRIS.
The afterglow is strongly detected in all exposures. Based on a preliminary wavelength solution, we identify in absorption a doublet and singlet complex which we identify as redshifted Mg I 2853 Ang, Mg II 2796, 2804 Ang at z = 1.314. We suggest this is redshift of GRB 0611121. Further analysis is ongoing."
This message may be cited.
GCN Circular #5827
A. Melandri (Liverpool JMU), C. Guidorzi (Univ Bicocca & INAF-OAB), C.G. Mundell, I.A. Steele, R.J. Smith, A. Monfardini, D. Carter, S. Kobayashi, D. Bersier, M. Bode (Liverpool JMU), A. Gomboc (University of Ljubljana), P. O'Brien, E. Rol, N. Bannister (Leicester) report:
The 2-m Faulkes North Telescope (Hawaii) automatically reacted to the Swift burst GRB061121 (trigger=239899, Page et al. GCN 5823).
Observations started about 4.4 min after the trigger time. We confirm the detection of the optical counterpart at the position
```
RA(J2000)  =  09:48:54.58
Dec(J2000) = -13:11:42.8
```
0.6" uncertainty, coincident with the UVOT and ROTSE counterpart (Yost et al. GCN 5824).
The automatic pipeline LT-TRAP identified a fading afterglow in BVRi' filters, and we estimate an initial magnitude R = 16.7 +/- 0.3 (wrt USNOB) at t=4.4min.
The temporal decay index between 4 and 20 minutes after the burst is alpha = 1.0 +/- 1.0.
Further observations and analysis are ongoing.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:40:20 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
ROLL:            109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56220.40 SOD {15:37:00.40} UT,   871.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     185816221
X_OFFSET:        709 [pixels]
Y_OFFSET:        1109 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       869
Y_GRB_POS:       1269
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0871.fits
SUN_POSTN:       236.97d {+15h 47m 53s}  -19.97d {-19d 58' 28"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.04d {+16h 20m 09s}  -26.36d {-26d 21' 21"}
MOON_DIST:        90.88 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:47:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.259d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 11' 00"} (J2000)
ROLL:            109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56325.64 SOD {15:38:45.64} UT,   976.6 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     185816327
X_OFFSET:        709 [pixels]
Y_OFFSET:        1109 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       869
Y_GRB_POS:       1269
BINNING_INDEX:   1
IM_URL:          sw00239899000msuni0976.fits
SUN_POSTN:       236.98d {+15h 47m 54s}  -19.98d {-19d 58' 31"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.11d {+16h 20m 26s}  -26.37d {-26d 22' 04"}
MOON_DIST:        90.93 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 21 Nov 06 15:33:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
POINT_ROLL:      109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  55516.10 SOD {15:25:16.10} UT,   167.1 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.676
N_STARS:         44
X_OFFSET:        390 [pixels]
Y_OFFSET:        790 [pixels]
X_MAX:           1349 [pixels]
Y_MAX:           1749 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00239899000msufc0167.fits
SUN_POSTN:       236.97d {+15h 47m 52s}  -19.97d {-19d 58' 24"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      244.97d {+16h 19m 53s}  -26.34d {-26d 20' 37"}
MOON_DIST:        90.82 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [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:     Tue 21 Nov 06 15:39:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     239899,   Seg_Num: 0
POINT_RA:        147.260d {+09h 49m 02s} (J2000)
POINT_DEC:       -13.183d {-13d 10' 59"} (J2000)
POINT_ROLL:      109.418d
IMG_START_DATE:  14060 TJD;   325 DOY;   06/11/21
IMG_START_TIME:  56220.40 SOD {15:37:00.40} UT,   871.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.998
N_STARS:         38
X_OFFSET:        390 [pixels]
Y_OFFSET:        790 [pixels]
X_MAX:           1349 [pixels]
Y_MAX:           1749 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00239899000msufc0871.fits
SUN_POSTN:       236.97d {+15h 47m 53s}  -19.97d {-19d 58' 27"}
SUN_DIST:         85.18 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      245.03d {+16h 20m 07s}  -26.35d {-26d 21' 15"}
MOON_DIST:        90.87 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      249.37, 30.15 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.40,-24.75 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN Circular #5828
M. Uemura, A. Arai, and T. Uehara (Hiroshima Univ.), report on behalf of the KANATA GRB team:
We started optical imaging of the field of GRB061121 using the TRISPEC attached to the KANATA 1.5-m telescope at Higashi-Hiroshima Observatory, Japan. We detected the optical afterglow reported in GCN 5823 and 5824 in our images taken with the exposure time of 123 s and the Rc filter. Using the comparison star USNOA2.0 0750-0732588 assuming Rc=14.2, our preliminary analysis yielded the following photometric result:
```
UT            Time after the burst (s)    Rc mag  
Nov. 21.71928         6797                18.539 +/- 0.074     
```
We keep time-series observations.
GCN Circular #5829
XMM-Newton will observe GRB 061121 at location (RA=09h 48m 54.3s, DEC=-13d 11' 45.9", J2000), starting at 21:25 UT, on Nov 21, 2006, for an exposure of 39800 seconds.
GCN Circular #5830
E. Sonoda, S. Maeno, T. Hara, T. Matsumura, K. Tanaka, H. Tanaka, M. Yamauchi (University of Miyazaki)
We have observed the field covering the error circle of GRB061121 (GCN 5823) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 18:09:09 UT, 2.77 hour after the Swift trigger time.
We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, there is no new source at the position reported by K. L. Page et al.(GCN 5823)
The upper limits are as follows:
```
--------------------------------------------------------------
Start(UT)       End(UT)     Num. of frames      Limit (mag.)
--------------------------------------------------------------
18:09:09        18:24:29        9               ~17
18:25:11        19:12:44        29              ~17.2
---------------------------------------------------------------
```
GCN Circular #5831
E. Fenimore (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. L. Page (U Leicester), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) on behalf of the Swift-BAT team:
Using the data set from T-240 to T+421 sec from the recent telemetry downlink, we report further analysis of BAT GRB 061121 (trigger #239899) (Page, et al., GCN Circ. 5823). The BAT ground-calculated position is RA,Dec = 147.228, -13.188 deg {9h 48m 54.8s, -13d 11' 16.6"} (J2000) +- 0.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted lightcurve starts with small smooth pulse at ~T-5 sec and returning to instrumental background level at T+20 sec. The the second and much brighter started at ~T+50 sec with a series of overlapping peaks the last of which was the brightest. Then there was roughly exponential decay out to ~T+200 sec. T90 (15-350 keV) is 81 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T-0.8 to T+121.8 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.41 +- 0.03. The fluence in the 15-150 keV band is 1.37 +- 0.02 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+74.48 sec in the 15-150 keV band is 21.1 +- 0.5 ph/cm2/sec.
The isotropic equivalent energy using the reported redshift of 1.314 (GCN Circ. 5826; Bloom, Perley & Chen) is 7e52 erg in the 35 keV - 347 keV band at the GRB rest frame.
All the quoted errors are at the 90% confidence level.
GCN Circular #5832
K.L. Page, R.L.C. Starling, J.P. Osborne (U. Leicester), E. Troja (U. Leicester/INAF-IASFPa) and D. Morris (PSU) report on behalf of the Swift-XRT team:
We have analysed the first 2 orbits (up to 8ks after the trigger) of Swift-XRT data obtained for GRB 061121 (Page et al., GCN Circ. 5823). Using ~3.2ks of Photon Counting (PC) data, we derive a refined position of
```
RA(J2000) =   09 48 54.54
Dec(J2000) = -13 11 42.4
```
with an estimated error radius of 3.5 arcsec (90% confidence, using the updated teldef file as described by Burrows et al. in GCN Circ. 5750). This is 4.0 and 0.7 arcsec from the original XRT and UVOT positions (GCN Circ. 5823) respectively.
Because the BAT triggered on a pre-cursor, XRT was on target for the main burst. The detected emission peaked at ~74s after the trigger, at a count rate of ~2400 count s^-1 (corrected for pile-up). After 200s, the decay follows a slope of alpha_1 = 0.36 +/- 0.07, until about 3ks after the trigger, when the decay steepens to alpha_2 = 1.4 +/- 0.4.
The Windowed Timing mode data between 200 and 600s after the trigger (i.e., when the data are clearly no longer piled-up) can be fitted with a photon index of 2.25 +/- 0.12, with a total absorbing column of 2.3e21 cm^-2; comparison with the PC data from orbit 2 shows no further spectral evolution. This absorption is significantly in excess of the Galactic value of 5.1e20 cm^-2. Taking the redshift to be 1.314 from the Keck measurement (GCN Circ. 5826; Bloom, Perley & Chen), the excess NH is equivalent to a value of 9.6e21 cm^-2 in the rest-frame of the burst. The observed (unabsorbed) flux for this spectrum is 2.51e-10 (3.81e-10) erg cm^-2 s^-1.
If the decay continues with a slope of alpha = 1.4, the estimated count rate at 24 hours is 0.031 count s^-1. This corresponds to an observed (unabsorbed) flux of 1.19e-12 (1.80e-12) erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular #5833
GRB 061121: Swift/UVOT Observations
F. E. Marshall (NASA/GSFC), S. T. Holland (NASA/GSFC & USRA), and K. L. Page (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began observing the field of GRB 061121 at 15:23:32 on 2006-11-21, 62 s after the BAT trigger (Page et al., GCN Cir. 5823). An optical counterpart was detected in the White filter (160-650 nm) at a position (RA,Dec) = (09:48:54.55, -13:11:42.4) (J2000) with a 90% confidence interval of 0.6 arcsec.
The afterglow was detected in each of the UVOT filters, and was still easily detected in the most recent exposure with the White filter 7026 seconds after the BAT trigger.
The early photometry results are given for the UVOT filters below where Midpoint is the average time of the exposure, in seconds, since the BAT trigger. The quoted errors do not include the 0.1 mag systematic uncertainty in the photometric zero points.
```
  Filter   Midpoint  Exposure  Mag  Err
  V         368       393     17.06 0.05
  B         650        10     17.7  0.2
  U         631        10     17.2  0.2
  UVW1     4981       197     19.6  0.2
  UVM2     6208       197     19.8  0.3
  UVW2     5800       197     20.4  0.3
  White     112        98     16.23 0.03
           7026       197     18.7  0.1
```
The values quoted above are not corrected for the expected Galactic extinction of E_{B-V} = 0.04 mag (Schlegel et al. 1998).
GCN Report 15.1
GCN_Report 15.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_15_1.pdf by K.L.Page at U. Leicester titled: "Swift Observations of GRB 061121"
GCN Circular #5837
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind and Konus-A teams report:
The second, brightest pulse of the long GRB 061121 (Swift-BAT trigger #239899: Page et al., GCN 5823; Fenimore et al., GCN 5831) triggered Konus-Wind at T0=55412.445 s UT(15:23:32.445). The first pulse which triggered Swift-BAT was detected by Konus-Wind in the waiting mode.
The Konus-Wind spectrum integrated over the main episode of emission (from T0 to T0+21.504 s) can be fitted (in the 20 keV - 5 MeV range) by a power law with exponential cutoff model: dN/dE ~ E^(-alpha) * exp(-(2-alpha)*E/Ep) with alpha = 1.32(-0.05, +0.04) and Ep = 606(-72, +90) keV (chi2 = 95/75 dof).
The fluence of this part is 5.67(-0.50, +0.30)x10^-5 erg/cm2 and the 64-ms peak flux measured from T0+12.960 s 1.28(-0.19, +0.16)x10^-5 erg/cm2/s (both in the 20 keV - 5 MeV range).
The fluence of the precursor is estimated as ~10^-6 erg/cm2, so the total burst fluence equals to the fluence of the main episode in the limits of its uncertainty.
Assuming z = 1.314 (Bloom, Perley, and Chen, GCN 5826) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.3, Omega_\Lambda = 0.7, the isotropic bolometric energy release is E_iso ~2.5x10^53 erg, and the maximum bolometric luminosity is (L_iso)_max ~1.3x10^53 erg/s.
All the quoted errors are at the 90% confidence level.
The GRB 061121 also triggered Konus-A at T0=55350.15 s UT (15:22:10.15) (so Konus-A triggered on the precursor). The Konus-A instrument has been operating onboard Cosmos-2421 spacecraft since June 25, 2006. The instrument consists of 3 NaI(Tl) detectors 200 mm in diameter and 50 mm in height with beryllium entrance windows. It is designed to study temporal and spectral characteristics of gamma-ray bursts in the wide energy range from 10 keV up to 10 MeV.
The Konus-Wind and Konus-A light curves of this GRB are available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB061121_T55412/
GCN Circular #5838
E. Bellm, M. Bandstra, S. Boggs, C. Wigger, W. Hajdas, D. M. Smith, and K. Hurley on behalf of the RHESSI team report:
As observed by RHESSI, GRB061121 (Page et al., GCN 5823) had a duration of ~19s starting at about T0=15:23:28 UT. The preliminary fit to the time-integrated RHESSI spectrum from T0 - T0+19s between 30 keV and 3 MeV is a Band function with
```
alpha = -0.83 +0.24/-0.19
beta = -2.00 +0.18/-0.32
E0 = 390. +250/-150. keV
Epeak = 455. +/-115. keV
(90% confidence levels).
```
The 30 keV-3 MeV fluence is 4.88 +/- 0.41 E-5 erg/cm^2.
GCN Circular #5839
N. Gehrels (GSFC), K. Page (U. Leicester), S. Barthelmy (GSFC), D. N. Burrows (PSU), F. Marshall (GSFC), P. Roming (PSU), T. Sakamoto (GSFC), G. Sato (GSFC) report on behalf of the Swift team:
The Swift team declares GRB 061121 to be a "burst of interest". It is bright in BAT, XRT and UVOT. It was observed by Konus-Wind, RHESSI, XRT, UVOT and ground-based optical telescope observations during the prompt phase, giving broad-band coverage of the burst. The Epeak and redshift have been determined. The X-ray afterglow has been observed by XMM. Swift will continue intensive observations of the afterglow as long as it is detectable. We encourage multiwavelength observations of the burst throughout its lightcurve.
Swift observations of GRB 061121 are discussed in GCN Report 15.1 (http://gcn.gsfc.nasa.gov/reports/report_15_1.pdf).
GCN Circular #5840
J. P. Halpern, N. Mirabal, & E. Armstrong (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team:
"We began R-band observations of GRB 061121 (Page et al., GCN 5823) 20.57 hr after the burst using the MDM 2.4m. Preliminary results from raw images are:
```
 -----------------------------------------------------------
  Date(UT)  Mid-time(UT)  t-t0(hr)  Exp(s)      R(mag)
 -----------------------------------------------------------
  Nov. 22      11:57       20.57     300     21.06 +/- 0.03
  Nov. 22      12:49       21.44     300     21.13 +/- 0.04
 -----------------------------------------------------------
```
These are referenced to the USNO B1.0 magnitude R=18.02 for the star at (J2000) R.A.=09h48m54.77s, Decl.= -13d11'17.9". Quoted errors are statistical only. Refined magnitudes and additional results will be forthcoming.
This message may be cited."
GCN Circular #5843
P. Chandra (UVA/NRAO) and D. 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 GRB061121 (GCN 5823) at a frequency of 8.46 GHz on 2006 November 22nd starting at 9.18 UT. We detected the radio afterglow of GRB (flux density of 304 +/- 48 uJy). Further observations are planned.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Circular #5844
S. B. Cenko (Caltech) reports on behalf of a larger collaboration:
We have imaged the field of GRB 061121 (Page et al., GCN 5823) with the automated Palomar 60-inch telescope. Observations consisted of 25 x 180 s exposures in the Kron R and Sloan i' filters, taken at a mean epoch of approximately 11:30 22 November UT (~ 20.1 hr after the burst).
The afterglow is clearly detected in our images, and we measure the following magnitudes (calculated with reference to the USNO-B catalog):
```
	R = 21.0 +/- 0.25
        I = 20.3 +/- 0.21
```
The large errors are dominated by photometric uncertainty. We note the R-band measurements are consistent with nearly-simultaneous observations reported by Halpern et al. (GCN 5840).
Further observations are planned.
GCN Circular #5845
K. Torii (Osaka U.) reports on behalf of the ART collaboration:
The error region of the bright GRB 061121 (Page et al. GCN 5823) was observed with the 14 inch ART-3a in Toyonaka. The imaging started at about 5 minutes after the trigger while the useful frames were obtained after 17:15 UT (t=113 minutes) when the object rose to 20 degrees above the horizon.
The optical afterglow (GCN 5823) is detected at 3.2 sigma in a stacked frame. Comparison with the USNO-B1.0 I2 mag gave the following measurement.
```
-----------------------------------------
StartUT         Filter  Mag     Exposure
=========================================
17:15:24        Ic      18.1    60s x 100
=========================================
```

GCN Circular #5847
J. P. Halpern, N. Mirabal, & E. Armstrong (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team:
"We observed the afterglow GRB 061121 (Page et al., GCN 5823) in the R band for a second night using the MDM 2.4m telescope. The following magnitudes from fully reduced images supersede and extend those reported by us in GCN 5840.

 ---------------------------------------------------------
  Date(UT)  Mid-time(UT)  t-t0(hr)  Exp(s)   R(mag)  +/-
 ---------------------------------------------------------
  Nov. 22      11:57       20.57     300     21.10   0.03
  Nov. 22      12:18       20.93     300     21.09   0.03
  Nov. 22      12:26       21.06     300     21.10   0.03
  Nov. 22      12:33       21.18     300     21.11   0.03
  Nov. 22      12:41       21.32     300     21.15   0.03
  Nov. 22      12:49       21.44     300     21.15   0.03

  Nov. 23      11:46       44.39     300     22.08   0.08
  Nov. 23      12:02       44.66     300     21.90   0.06
  Nov. 23      12:08       44.76     300     21.92   0.06
  Nov. 22      12:14       44.86     300     22.02   0.07
  Nov. 23      12:20       44.96     300     21.98   0.07
  Nov. 23      12:28       45.09     300     22.08   0.07
  Nov. 23      12:36       45.23     300     21.99   0.07
  Nov. 23      12:46       45.40     600     22.01   0.05
  Nov. 23      12:57       45.58     600     22.13   0.07
 ---------------------------------------------------------

Magnitudes are referenced to a single USNO-B1.0 star at (J2000) R.A.=09h48m54.77s, Decl.= -13d11'17.9" with R=18.02. Quoted uncertainties are statistical only.
The power-law decay index from 21 to 45 hours is -1.08+/-0.03.
Images are posted at http://www.astro.columbia.edu/~jules/grb/061121/
This message may be cited."

GCN Circular #5848
L. Amati (INAF-IASF Bologna), F. Frontera (Univ.Ferrara and INAF-IASF Bologna), C. Guidorzi (Univ.Bicocca/INAF and Osservatorio Astronomico di Brera), E. Montanari (Univ.Ferrara) and M. Della Valle (INAF-Osservatorio Astrofisico di Arcetri) report:
"Based on the redshift of 1.314 (GCN 5826) and the fluence and spectral properties of the prompt emission as measured by Konus-Wind (GCN 5837) and RHESSI (GCN 5838), we estimate for GRB 061121 a total isotropic released energy, Eiso, of ~(3+/-0.3)x10^(53) erg (1-10000 keV cosmological rest-frame, H0=65 km/s/Mpc, Omega_m=0.3, Omega_lambda=0.7) and an intrinsic peak energy, Ep,i, of ~1200+/-400 keV. These values are consistent with the best fit of the Ep,i-Eiso correlation within ~0.9 - 2.3 sigma (see, e.g., Figure 1 of Amati et al. 2006, astro-ph/0607148v4).
Given that the Konus-Wind and RHESSI spectra were measured during the brighter and harder portion of the event (~20s), the inclusion in the spectral analysis of the BAT and XRT data covering the whole prompt emission (i.e. up to ~120 s from the Swift trigger, see GCN Report 15.1) may provide a lower value of Ep,i and a slightly higher value of Eiso, improving the match with the Ep,i-Eiso correlation."
This message may be cited.
GCN Circular #5850
Yu. Efimov, V. Rumyantsev (CrAO), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed error box of GRB061121 (Page et al., GCN 5823) with Shajn 2.6m telescope of CrAO. A set of exposures was taken on Nov. 22 in B,R under poor weather conditions and a set of 22x180 s R-exposures on Nov.23. The afterglow (Page et al., GCN 5823; Yost et al., GCN 5824) is not detected in a single images of 60 s exposure on Nov.22 and clearly visible on a single images of 180 s on Nov. 23. For the analysis of Nov. 22 observation we take the best single image while for Nov.23 observation we use two combined images. Preliminary data reduction of the observations is following:
```
Mid time   Exposure,  R_mag,    Lim_mag (3 sigma)
(UT)          s

Nov. 22.1309   1x60     n/d          20.60
Nov. 23.1040  11x180  21.37 +/- 0.05 23.55
Nov. 23.1329  11x180  21.47 +/- 0.06 23.49
```
Above estimations are based on USNO A2.0 star RA=09 48 57.46 Dec=-13 13 20.10 R=17.30. The combine image of the last epoch can be found in http://grb.rssi.ru/GRB061121/GRB061121_20061122_ZTSh_R
This message may be cited.
GCN Circular #5851
J. P. Halpern & E. Armstrong (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team:
"Continuing observations of GRB 061121 for a third night on the MDM 2.4m telescope yield the following results, using the same calibration as in GCN 5847:
```
 ---------------------------------------------------------
  Date(UT)  Mid-time(UT)  t-t0(hr)  Exp(s)   R(mag)  +/-
 ---------------------------------------------------------
  Nov. 24      11:43       68.34     900     22.32   0.04
  Nov. 24      12:04       68.69    1200     22.33   0.03
  Nov. 24      12:35       69.21    1500     22.41   0.03
  Nov. 24      12:55       69.54     600     22.36   0.08
 ---------------------------------------------------------
```
This indicates a slight flattening or deviation from the previously fitted power-law decay.
Images and light curve are posted at
http://www.astro.columbia.edu/~jules/grb/061121/
This message may be cited."
GCN Circular #5853
J. P. Halpern & E. Armstrong (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team:
"Continuing observations of GRB 061121 for a fourth night on the MDM 2.4m telescope yield the following results, using the same calibration as in GCN 5847:
```
 ---------------------------------------------------------
  Date(UT)  Mid-time(UT)  t-t0(hr)  Exp(s)   R(mag)  +/-
 ---------------------------------------------------------
  Nov. 25      11:42       92.33     900     22.69   0.06
  Nov. 25      12:02       92.66     900     22.64   0.05
  Nov. 25      12:20       92.96     900     22.75   0.08
 ---------------------------------------------------------
```
A power-law decay index of -0.979+/-0.015 is fitted to the four nights.
Images and light curve are posted at
http://www.astro.columbia.edu/~jules/grb/061121/
This message may be cited."
GCN Circular #5870
Yu. Efimov, V. Rumyantsev (CrAO), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed an afterglow GRB061121 (Page et al., GCN 5823; Yost et al., GCN 5824) with Shajn 2.6m telescope of CrAO on Nov. 24. A photometry of the afterglow in a combined image is following:
```
Mid time   Exposure,  R_mag,    Lim_mag (3 sigma)
(UT)          s

Nov. 24.0823   41x120  21.96 +/- 0.07 23.6
```
The photometry is based on the same calibration as in our previous GCN 5850. A power-law decay index between Nov. 23.1040 observation (Efimov et al., GCN 5850) and Nov. 24.0823 (this circular) is 1.06 and compatible with the index reported in GCN 5847 (Halpern et al.) for early afterglow decay.
This message may be cited.
GCN Circular #5871
A.J. van der Horst, R.A.M.J. Wijers (University of Amsterdam) and E. Rol (University of Leicester) report on behalf of a larger collaboration:
"We observed the position of the GRB 061121 afterglow (GCN 5823) at 2.3 GHz with the Westerbork Synthesis Radio Telescope, and at 4.8 and 8.6 GHz with the Australia Telescope Compact Array. We do not detect a radio counterpart of the optical afterglow (GCN 5824). Our results are given in the table below. We note that the three-sigma flux limit at 8.6 GHz at ~5.2 days after the burst is significantly lower than the VLA detection at ~0.8 days after the burst (GCN 5843).
```
Epoch            Delta T   Frequency  3-sigma rms noise  Formal flux
===============  ========  =========  =================  ==============
Nov 26.76-26.92  5.2 days  8.6 GHz    246 uJy/beam        10 +/- 82 uJy
Nov 26.76-26.92  5.2 days  4.8 GHz    210 uJy/beam        13 +/- 70 uJy
Nov 27.01-27.30  5.5 days  2.3 GHz    144 uJy/beam       -50 +/- 48 uJy
```
We would like to thank the WSRT staff for obtaining these observations in between VLBI observation runs. Also we would like to thank the staff of the Australia Telescope National Facility, in particular Philip Edwards, for obtaining these Target of Opportunity observations."
GCN Circular #5874
A.J. van der Horst, R.A.M.J. Wijers (University of Amsterdam) and E. Rol (University of Leicester) report on behalf of a larger collaboration:
"We reobserved the position of the GRB 061121 afterglow at 4.8 and 8.6 GHz with the Australia Telescope Compact Array at November 27 14.11 UT to 20.88 UT, i.e. 5.95 - 6.23 days after the burst (GCN 5823). We do not detect a radio source at the position of the optical afterglow (GCN 5824). The three-sigma rms noise in het map around that position is 126 microJy per beam at 4.8 GHz, and 129 microJy per beam at 8.6 GHz. The formal flux measurement for a point source at the location of the optical afterglow is 7 +/- 42 microJy at 4.8 GHz, and -20 +/- 43 microJy at 8.6 GHz.
We would like to thank the staff of the Australia Telescope National Facility, in particular Philip Edwards, for obtaining these Target of Opportunity observations."
GCN Circular #5877
D. Malesani, J. Hjorth, D. Xu, M.D. Stritzinger, D. Watson, J.P.U. Fynbo, (NBI-Dark), C. Henriksen, K. Holjem, T. Pursimo, D. Sharapov, H. Uthas (NOT), report:
We have observed the afterglow of GRB 061121 (Page et al., GCN 5823) at several epochs with NOT + ALFOSC. Starting from 2006 Nov. 25 on, the R-band light curve significantly flattened with respect to earlier observations (e.g. Halpern et al., GCN 5847; Efimov et al., GCN 5870). This is likely due to the presence of a relatively bright underlying host galaxy. Some hints of extension are seen in our images taken during the night of Nov 27, with a seeing of 0.9".
GCN Circular #5878
B. E. Cobb (Yale), part of the larger SMARTS consortium, reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 061121 (GCN 5823, Page et al.) at several epochs. At a mid-exposure time of 2006-11-22 07:34 UT (16.2 hours post-burst), the afterglow is detected in a 36 minute I-band image with a magnitude of I=20.1+/-0.1. No afterglow is detected in a 30 minute J-band image (with the same mid-exposure time) to a limiting magnitude of J>19.0+/-0.1.
In two subsequent epochs (mid-exposure times: 64.7 and 87.8 hours post-burst), 15 minute I and V exposures and 12 minute J and K exposures were obtained. At the position of the optical afterglow, a possibly extended source is detected in both V-band images. The source does not appear to vary significantly between epochs and, therefore, may be the host galaxy of GRB 061121 (also noted by Malesani et al., GCN 5877), with a magnitude of V=22.4+/-0.2. This source is detected, with low significance, in each I-band image. In a combined image of the 2 I-band epochs, the source has a magnitude of I=21.9+/-0.2. The source is also detected just slightly above the background in a combined J-band image, which has a 3 sigma limiting magnitude of J>19.3+/-0.1. The source is not detected in the K-band, to a limiting magnitude of K>17.8+/-0.1. All magnitudes are calibrated using 2MASS stars in IR and Landolt standard stars in the optical.
GCN Circular #5899
F.E. Marshall (NASA/GSFC) reports on behalf of the Swift/UVOT team:
The exposure times for UVOT were reported incorrectly for GRB 061110B in GCN Circ. 5803 and for GRB 061121 in GCN Circ. 5823 because of a configuration problem in the instrument. The actual exposure times are close to the nominal values of 100 s and 400 s (Page et al., GCN Report 15.1) respectively.
We caution users of UVOT data that data in the archives for exposures taken between November 10 and November 22, 2006, have an incorrect value for the frame time. As a consequence, the standard UVOT analysis tools do not calculate dead time and anti-coincidence losses properly. Additional details, including the proper technique for analyzing these data, are available on the following web page:
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_frame.html
GCN Report 15.2
GCN_Report 15.2 has been posted: http://gcn.gsfc.nasa.gov/reports/report_15_2.pdf by K.L. Page at U. Leicester titled: "Final Report on Swift Observations of GRB 061121"
GCN Circular #6717
M. Schubel, C. Weaver, T. Brennan, J. Styblova, J. Haislip, D. Reichart, M. Nysewander, A. LaCluyze, K. Ivarsen, J. A. Crain, A. Foster, and A. Trotter report:
Skynet observed the localization of GRB 061121A (Page et al., GCN 5823) with two of the 16" PROMPT telescopes at CTIO beginning 14.5 hours after the burst in r'i'z'.
We do not detect the afterglow (Page et al., GCN 5823) to 3-sigma limiting magnitudes of r' = 17.2 mag at a mean time of 14.7 hours after the burst (10 x 80 sec, calibrated to 13 stars), i' = 19.2 mag at a mean time of 16.3 hours after the burst (75 x 80 sec, calibrated to 14 stars), and z' = 18.6 (65 x 80 sec, calibrated to 21 stars) at a mean time of 16.4 hours after the burst.
Limiting magnitudes are calibrated to USNO B1.0 and NOMAD stars using the transformation equations of Smith et al. 2002, AJ, 123, 2121.

Back to JG's homepage

Jochen Greiner, last update: 08-Aug-2007 [Disclaimer]