Gamma-ray Burst 120121A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:43:00 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     512164,   Seg_Num: 0
GRB_RA:          249.336d {+16h 37m 21s} (J2000),
                 249.519d {+16h 38m 04s} (current),
                 248.581d {+16h 34m 19s} (1950)
GRB_DEC:         -23.954d {-23d 57' 14"} (J2000),
                 -23.978d {-23d 58' 39"} (current),
                 -23.854d {-23d 51' 15"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       13151 [cnts]    Image_Peak=461 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   298     E_range: 25-100 keV
BKG_INTEN:       113136 [cnts]
BKG_TIME:        34880.19 SOD {09:41:20.19} UT
BKG_DUR:         40 [sec]
GRB_DATE:        15947 TJD;    21 DOY;   12/01/21
GRB_TIME:        34939.26 SOD {09:42:19.26} UT
GRB_PHI:         -26.07 [deg]
GRB_THETA:        32.99 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     8.94 [sigma]
IMAGE_SIGNIF:    9.97 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +2  +0  +0  +1 -64  +0 
SUN_POSTN:       302.95d {+20h 11m 49s}  -19.99d {-19d 59' 20"}
SUN_DIST:         49.43 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      276.94d {+18h 27m 46s}  -21.17d {-21d 10' 24"}
MOON_DIST:        25.44 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.31 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      251.18, -1.86 [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 = 322.55,19.01 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:44:26 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.976d {-23d 58' 33"} (J2000)
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35058.72 SOD {09:44:18.72} UT,   119.5 [sec] since BAT Trigger Time
COUNTS:          2    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:46:02 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     512164,   Seg_Num: 0
GRB_RA:          249.336d {+16h 37m 21s} (J2000),
                 249.519d {+16h 38m 04s} (current),
                 248.581d {+16h 34m 19s} (1950)
GRB_DEC:         -23.954d {-23d 57' 14"} (J2000),
                 -23.978d {-23d 58' 39"} (current),
                 -23.854d {-23d 51' 15"} (1950)
GRB_DATE:        15947 TJD;    21 DOY;   12/01/21
GRB_TIME:        34939.26 SOD {09:42:19.26} UT
TRIGGER_INDEX:   298
GRB_PHI:         -26.07 [deg]
GRB_THETA:        32.99 [deg]
DELTA_TIME:      12.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     8.94 [sigma]
IMAGE_SIGNIF:    9.97 [sigma]
LC_URL:          sw00512164000msb.lc
SUN_POSTN:       302.96d {+20h 11m 50s}  -19.99d {-19d 59' 19"}
SUN_DIST:         49.43 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      276.97d {+18h 27m 54s}  -21.17d {-21d 10' 11"}
MOON_DIST:        25.47 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.31 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      251.18, -1.86 [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 = 322.55,19.01 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:53:18 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 29"} (J2000)
POINT_ROLL:      96.492d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35063.00 SOD {09:44:23.00} UT,   123.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        9.230
N_STARS:         60
X_OFFSET:        239 [pixels]
Y_OFFSET:        543 [pixels]
X_MAX:           1198 [pixels]
Y_MAX:           1502 [pixels]
DET_THRESH:      27
PHOTO_THRESH:    17
SL_URL:          sw00512164000msufc0123.fits
SUN_POSTN:       302.96d {+20h 11m 51s}  -19.99d {-19d 59' 15"}
SUN_DIST:         49.41 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.05d {+18h 28m 12s}  -21.16d {-21d 09' 38"}
MOON_DIST:        25.51 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:53:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 29"} (J2000)
POINT_ROLL:      96.492d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35063.00 SOD {09:44:23.00} UT,   123.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        9.230
N_STARS:         60
X_OFFSET:        239 [pixels]
Y_OFFSET:        543 [pixels]
X_MAX:           1198 [pixels]
Y_MAX:           1502 [pixels]
DET_THRESH:      27
PHOTO_THRESH:    17
SL_URL:          sw00512164000msufc0123.fits
SUN_POSTN:       302.96d {+20h 11m 51s}  -19.99d {-19d 59' 15"}
SUN_DIST:         49.41 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.05d {+18h 28m 13s}  -21.16d {-21d 09' 35"}
MOON_DIST:        25.52 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:54:56 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 29"} (J2000)
ROLL:            96.492d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35063.00 SOD {09:44:23.00} UT,   123.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     348831870
X_OFFSET:        558 [pixels]
Y_OFFSET:        862 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       718
Y_GRB_POS:       1022
BINNING_INDEX:   1
IM_URL:          sw00512164000msuni0131.fits
SUN_POSTN:       302.96d {+20h 11m 51s}  -19.99d {-19d 59' 14"}
SUN_DIST:         49.41 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.06d {+18h 28m 16s}  -21.16d {-21d 09' 30"}
MOON_DIST:        25.53 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 09:55:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 29"} (J2000)
ROLL:            96.492d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35063.00 SOD {09:44:23.00} UT,   123.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     348831870
X_OFFSET:        558 [pixels]
Y_OFFSET:        862 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       718
Y_GRB_POS:       1022
BINNING_INDEX:   1
IM_URL:          sw00512164000msuni0131.fits
SUN_POSTN:       302.96d {+20h 11m 51s}  -19.99d {-19d 59' 14"}
SUN_DIST:         49.41 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.07d {+18h 28m 16s}  -21.16d {-21d 09' 29"}
MOON_DIST:        25.53 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #12885
K. L. Page (U Leicester), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), J. A. Kennea (PSU), D. M. Palmer (LANL), M. H. Siegel (PSU), R. L. C. Starling (U Leicester) and B.-B. Zhang (PSU) report on behalf of the Swift Team:
At 09:42:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120121A (trigger=512164). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 249.336, -23.954 which is
```
   RA(J2000) = 16h 37m 21s
   Dec(J2000) = -23d 57' 14"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked FRED structure with a duration of about 40 sec. The peak count rate was ~800 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 09:44:18.7 UT, 119.4 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart.
UVOT took a finding chart exposure of 150 seconds with the White filter starting 123 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.84.
Burst Advocate for this burst is K. L. Page (kpa AT star.le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:13:07 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.365d {+16h 37m 28s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
POINT_ROLL:      96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35274.95 SOD {09:47:54.95} UT,   335.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        3.226
N_STARS:         53
X_OFFSET:        0 [pixels]
Y_OFFSET:        303 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1742 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00512164000msufc0335.fits
SUN_POSTN:       302.98d {+20h 11m 54s}  -19.98d {-19d 59' 04"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.25d {+18h 29m 00s}  -21.14d {-21d 08' 08"}
MOON_DIST:        25.70 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:13:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.365d {+16h 37m 28s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
POINT_ROLL:      96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35274.95 SOD {09:47:54.95} UT,   335.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        3.226
N_STARS:         53
X_OFFSET:        0 [pixels]
Y_OFFSET:        303 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1742 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00512164000msufc0335.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 04"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.25d {+18h 29m 01s}  -21.14d {-21d 08' 06"}
MOON_DIST:        25.70 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:14:43 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.365d {+16h 37m 28s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
ROLL:            96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35274.95 SOD {09:47:54.95} UT,   335.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     348832082
X_OFFSET:        559 [pixels]
Y_OFFSET:        862 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       719
Y_GRB_POS:       1022
BINNING_INDEX:   1
IM_URL:          sw00512164000msuni0343.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 03"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.27d {+18h 29m 04s}  -21.13d {-21d 08' 00"}
MOON_DIST:        25.72 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:15:09 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
POINT_ROLL:      96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35803.50 SOD {09:56:43.50} UT,   864.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.294
N_STARS:         190
X_OFFSET:        0 [pixels]
Y_OFFSET:        303 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1742 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00512164000msufc0864.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 03"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.27d {+18h 29m 05s}  -21.13d {-21d 07' 58"}
MOON_DIST:        25.72 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:15:02 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.365d {+16h 37m 28s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
ROLL:            96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35274.95 SOD {09:47:54.95} UT,   335.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     348832082
X_OFFSET:        559 [pixels]
Y_OFFSET:        862 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       719
Y_GRB_POS:       1022
BINNING_INDEX:   1
IM_URL:          sw00512164000msuni0343.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 03"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.27d {+18h 29m 05s}  -21.13d {-21d 07' 59"}
MOON_DIST:        25.72 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:15:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
POINT_ROLL:      96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35803.50 SOD {09:56:43.50} UT,   864.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.294
N_STARS:         190
X_OFFSET:        0 [pixels]
Y_OFFSET:        303 [pixels]
X_MAX:           1439 [pixels]
Y_MAX:           1742 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00512164000msufc0864.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 02"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.28d {+18h 29m 07s}  -21.13d {-21d 07' 56"}
MOON_DIST:        25.73 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:16:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
ROLL:            96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35803.50 SOD {09:56:43.50} UT,   864.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     348832611
X_OFFSET:        559 [pixels]
Y_OFFSET:        862 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       719
Y_GRB_POS:       1022
BINNING_INDEX:   1
IM_URL:          sw00512164000msuni0872.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 02"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.29d {+18h 29m 09s}  -21.13d {-21d 07' 52"}
MOON_DIST:        25.73 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:16:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     512164,   Seg_Num: 0
POINT_RA:        249.364d {+16h 37m 27s} (J2000)
POINT_DEC:       -23.975d {-23d 58' 28"} (J2000)
ROLL:            96.493d
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35803.50 SOD {09:56:43.50} UT,   864.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     348832611
X_OFFSET:        559 [pixels]
Y_OFFSET:        862 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       719
Y_GRB_POS:       1022
BINNING_INDEX:   1
IM_URL:          sw00512164000msuni0872.fits
SUN_POSTN:       302.98d {+20h 11m 55s}  -19.98d {-19d 59' 02"}
SUN_DIST:         49.42 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.29d {+18h 29m 10s}  -21.13d {-21d 07' 50"}
MOON_DIST:        25.74 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.28 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      251.20, -1.87 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 21 Jan 12 10:54:42 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     512164,   Seg_Num: 0
GRB_RA:          249.3547d {+16h 37m 25.12s} (J2000),
                 249.5371d {+16h 38m 08.90s} (current),
                 248.5990d {+16h 34m 23.74s} (1950)
GRB_DEC:         -23.9618d {-23d 57' 42.4"} (J2000),
                 -23.9854d {-23d 59' 07.3"} (current),
                 -23.8619d {-23d 51' 42.9"} (1950)
GRB_ERROR:       3.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15947 TJD;    21 DOY;   12/01/21
IMG_START_TIME:  35069.00 SOD {09:44:29.00} UT,   129.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       303.01d {+20h 12m 02s}  -19.98d {-19d 58' 41"}
SUN_DIST:         49.46 [deg]   Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN:      277.68d {+18h 30m 43s}  -21.08d {-21d 04' 55"}
MOON_DIST:        26.11 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      355.11, 15.29 [deg] galactic lon,lat of the burst
ECL_COORDS:      251.19, -1.86 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 1.1% < P(seren) < 2.8%.

GCN Circular #12886
K.L. Page and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Using promptly downlinked data we find an X-ray source with an enhanced position: RA,Dec = 249.3547, -23.9618 (degrees) which is equivalent to:
```
RA  (J2000.0) = 16 37 25.13
DEC (J2000.0) = -23 57 42.4
```
with an uncertainty of 3.2 arcsec (radius, 90% containment). This location is 67.6 arcseconds from the BAT onboard position, inside the BAT error circle. It is not yet possible to determine whether the source is fading.
GCN Circular #12887
L. Elenin (KIAM), A. Pozanenko (IKI), A. Volnova (SAI MSU), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 120121A (Page et al., GCN 12885) with 0.45-m telescope ISON-NM observatory on Jan. 21. We took several unfiltered images of 60 s exposure on Jan. 21, starting (UT) 12:29:25. We do not detect any object within the XRT error circle (Page et al., GCN 12886 ), down to 19.7m (calibrated against the USNO B1.0 catalog).
GCN Circular #12888
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1511 s of XRT Photon Counting mode data and 2 UVOT images for GRB 120121A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 249.35428, -23.96156 which is equivalent to:
```
RA (J2000): 16h 37m 25.03s
Dec (J2000): -23d 57' 41.6"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #12889
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120121A (trigger #512164) (Page, et al., GCN Circ. 12885). The BAT ground-calculated position is RA, Dec = 249.363, -23.963 deg which is
```
   RA(J2000)  =  16h 37m 27.1s 
   Dec(J2000) = -23d 57' 45.9" 
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 70%.
The mask-weighted light curve shows several overlapping peaks starting at ~T-10 sec, peaking at ~T+2 sec, and ending at ~T+70 sec. T90 (15-350 keV) is 26.1 +- 3.1 sec (estimated error including systematics).
The time-averaged spectrum from T-11.00 to T+18.33 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.23 +- 0.13. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.86 sec in the 15-150 keV band is 0.7 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/512164/BA/
GCN Circular #12890
K. L. Page (U Leicester) reports on behalf of the Swift-XRT team:
We have analysed 9.8 ks of XRT data for GRB 120121A (Page et al. GCN Circ. 12885), from 130 s to 23.1 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 12888).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.88 (+0.09, -0.08).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.0 (+0.7, -0.6). The best-fitting absorption column is 2.4 (+1.3, -0.9) x 10^22 cm^-2, in excess of the Galactic value of 1.2 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 7.5 x 10^-11 (2.0 x 10^-10) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.4 (+1.3, -0.9) x 10^22 cm^-2
Galactic foreground: 1.2 x 10^21 cm^-2
Excess significance: 4.3 sigma
Photon index:	     2.0 (+0.7, -0.6)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00512164.
This circular is an official product of the Swift-XRT team.
GCN Circular #12891
F. E. Marshall (NASA/GSFC) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 120121A 124 s after the BAT trigger (Page et al., GCN Circ. 12885). No optical afterglow consistent with the XRT position (Evans et al., GCN Circ. 12888) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           124          273          147         >20.2
u_FC               336          585          246         >19.7
white              124         6777          673         >21.1
v                  664         7188          510         >18.9
b                  591        13219         1160         >20.2
u                  336        18998         2078         >20.2
w1                 714        18281         2108         >20.4
m2               16474        17374          886         >20.1
w2                1020        23198         1298         >21.1
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.87 in the direction of the burst (Schlegel et al. 1998).
GCN Report 357.1
GCN_Report 357.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_357_1.pdf by K.L. Page at U. Leicester titled: "Final Swift Observations of GRB 120121A"

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Jochen Greiner, last update: 21-Jan-2012 [Disclaimer]