Gamma-ray Burst 121217A

(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:     Mon 17 Dec 12 07:18:13 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     542441,   Seg_Num: 0
GRB_RA:          153.724d {+10h 14m 54s} (J2000),
                 153.829d {+10h 15m 19s} (current),
                 153.318d {+10h 13m 16s} (1950)
GRB_DEC:         -62.304d {-62d 18' 13"} (J2000),
                 -62.369d {-62d 22' 06"} (current),
                 -62.055d {-62d 03' 16"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4867 [cnts]    Image_Peak=240 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       27839 [cnts]
BKG_TIME:        26254.00 SOD {07:17:34.00} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16278 TJD;   352 DOY;   12/12/17
GRB_TIME:        26267.89 SOD {07:17:47.89} UT
GRB_PHI:         -89.70 [deg]
GRB_THETA:        10.48 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     20.49 [sigma]
IMAGE_SIGNIF:    8.88 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -1  +0  +1 -19  +0 
SUN_POSTN:       265.38d {+17h 41m 31s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.75 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.62d {+21h 22m 28s}   -9.95d {-09d 56' 57"}
MOON_DIST:       106.96 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.81, -4.75 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      201.41,-63.41 [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 = 321.79,18.46 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:19:26 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     542441,   Seg_Num: 0
GRB_RA:          153.7050d {+10h 14m 49.20s} (J2000),
                 153.8101d {+10h 15m 14.41s} (current),
                 153.3003d {+10h 13m 12.07s} (1950)
GRB_DEC:         -62.3503d {-62d 21' 01.0"} (J2000),
                 -62.4150d {-62d 24' 54.0"} (current),
                 -62.1011d {-62d 06' 04.1"} (1950)
GRB_ERROR:       5.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.93e-09 [erg/cm2/sec]
GRB_SIGNIF:      7.87 [sigma]
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26331.89 SOD {07:18:51.89} UT,   64.0 [sec] since BAT Trigger Time
TAM[0-3]:        327.63 237.20 261.51 243.67
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       265.38d {+17h 41m 31s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.74 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.63d {+21h 22m 31s}   -9.95d {-09d 56' 44"}
MOON_DIST:       106.92 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.83, -4.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      201.48,-63.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.84 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:19:46 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     542441,   Seg_Num: 0
GRB_RA:          153.7050d {+10h 14m 49.2s} (J2000),
                 153.8101d {+10h 15m 14.4s} (current),
                 153.3003d {+10h 13m 12.0s} (1950)
GRB_DEC:         -62.3503d {-62d 21' 01.0"} (J2000),
                 -62.4150d {-62d 24' 54.0"} (current),
                 -62.1011d {-62d 06' 04.1"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       62 [cnts]
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26331.89 SOD {07:18:51.89} UT,   64.0 [sec] since BAT Trigger Time
CENTROID_X:      262.87,  raw= 263  [pixels]
CENTROID_Y:      230.53,  raw= 231  [pixels]
ROLL:            119.61 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -159.03
GRB_POS_XRT_Z:   -96.24
IMAGE_URL:       sw00542441000msxps_rw.img
SUN_POSTN:       265.38d {+17h 41m 31s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.74 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.63d {+21h 22m 32s}   -9.94d {-09d 56' 40"}
MOON_DIST:       106.92 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.83, -4.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      201.48,-63.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:19:38 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     542441,   Seg_Num: 0
GRB_RA:          153.7050d {+10h 14m 49.2s} (J2000),
                 153.8101d {+10h 15m 14.4s} (current),
                 153.3003d {+10h 13m 12.0s} (1950)
GRB_DEC:         -62.3503d {-62d 21' 01.0"} (J2000),
                 -62.4150d {-62d 24' 54.0"} (current),
                 -62.1011d {-62d 06' 04.1"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       62 [cnts]
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26331.89 SOD {07:18:51.89} UT,   64.0 [sec] since BAT Trigger Time
CENTROID_X:      262.87,  raw= 263  [pixels]
CENTROID_Y:      230.53,  raw= 231  [pixels]
ROLL:            119.61 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -159.03
GRB_POS_XRT_Z:   -96.24
IMAGE_URL:       sw00542441000msxps_rw.img
SUN_POSTN:       265.38d {+17h 41m 31s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.74 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.63d {+21h 22m 31s}   -9.95d {-09d 56' 41"}
MOON_DIST:       106.92 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.83, -4.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      201.48,-63.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:21:33 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     542441,   Seg_Num: 0
GRB_RA:          153.724d {+10h 14m 54s} (J2000),
                 153.829d {+10h 15m 19s} (current),
                 153.318d {+10h 13m 16s} (1950)
GRB_DEC:         -62.304d {-62d 18' 13"} (J2000),
                 -62.369d {-62d 22' 06"} (current),
                 -62.055d {-62d 03' 16"} (1950)
GRB_DATE:        16278 TJD;   352 DOY;   12/12/17
GRB_TIME:        26267.89 SOD {07:17:47.89} UT
TRIGGER_INDEX:   146
GRB_PHI:         -89.70 [deg]
GRB_THETA:        10.48 [deg]
DELTA_TIME:      52.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     20.49 [sigma]
IMAGE_SIGNIF:    8.88 [sigma]
LC_URL:          sw00542441000msb.lc
SUN_POSTN:       265.38d {+17h 41m 31s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.75 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.65d {+21h 22m 36s}   -9.94d {-09d 56' 20"}
MOON_DIST:       106.97 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.81, -4.75 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      201.41,-63.41 [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 = 321.79,18.46 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:23:30 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.705d {+10h 14m 49s} (J2000)
POINT_DEC:       -62.299d {-62d 17' 56"} (J2000)
POINT_ROLL:      119.606d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26340.63 SOD {07:19:00.63} UT,   72.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.188
N_STARS:         190
X_OFFSET:        560 [pixels]
Y_OFFSET:        512 [pixels]
X_MAX:           1519 [pixels]
Y_MAX:           1471 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00542441000msufc0072.fits
SUN_POSTN:       265.38d {+17h 41m 32s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.76 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.67d {+21h 22m 40s}   -9.93d {-09d 55' 58"}
MOON_DIST:       106.98 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:24:03 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.705d {+10h 14m 49s} (J2000)
POINT_DEC:       -62.299d {-62d 17' 56"} (J2000)
POINT_ROLL:      119.606d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26340.63 SOD {07:19:00.63} UT,   72.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.188
N_STARS:         190
X_OFFSET:        560 [pixels]
Y_OFFSET:        512 [pixels]
X_MAX:           1519 [pixels]
Y_MAX:           1471 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00542441000msufc0072.fits
SUN_POSTN:       265.38d {+17h 41m 32s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.76 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.67d {+21h 22m 41s}   -9.93d {-09d 55' 52"}
MOON_DIST:       106.99 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:25:30 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.705d {+10h 14m 49s} (J2000)
POINT_DEC:       -62.299d {-62d 17' 56"} (J2000)
ROLL:            119.606d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26340.63 SOD {07:19:00.63} UT,   72.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     377421550
X_OFFSET:        1131 [pixels]
Y_OFFSET:        1054 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1291
Y_GRB_POS:       1214
BINNING_INDEX:   1
IM_URL:          sw00542441000msuni0082.fits
SUN_POSTN:       265.38d {+17h 41m 32s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.76 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.69d {+21h 22m 44s}   -9.93d {-09d 55' 36"}
MOON_DIST:       106.99 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:25:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.705d {+10h 14m 49s} (J2000)
POINT_DEC:       -62.299d {-62d 17' 56"} (J2000)
ROLL:            119.606d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26340.63 SOD {07:19:00.63} UT,   72.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     377421550
X_OFFSET:        1131 [pixels]
Y_OFFSET:        1054 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1291
Y_GRB_POS:       1214
BINNING_INDEX:   1
IM_URL:          sw00542441000msuni0082.fits
SUN_POSTN:       265.38d {+17h 41m 32s}  -23.37d {-23d 22' 08"}
SUN_DIST:         78.76 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.69d {+21h 22m 45s}   -9.93d {-09d 55' 32"}
MOON_DIST:       106.99 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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/FERMI NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:30:29 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     377422204
GRB_RA:          178.117d {+11h 52m 28s} (J2000),
                 178.274d {+11h 53m 06s} (current),
                 177.516d {+11h 50m 04s} (1950)
GRB_DEC:         -75.283d {-75d 16' 59"} (J2000),
                 -75.355d {-75d 21' 19"} (current),
                 -75.005d {-75d 00' 17"} (1950)
GRB_ERROR:       17.57 [deg radius, statistical plus systematic]
GRB_INTEN:       59 [cnts/sec]
DATA_SIGNIF:     5.20 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        16278 TJD;   352 DOY;   12/12/17
GRB_TIME:        27001.58 SOD {07:30:01.58} UT
GRB_PHI:          86.00 [deg]
GRB_THETA:        40.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.69
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      66%  Distant Particles
2nd_MOST_LIKELY:  25%  GRB
DETECTORS:       0,1,0, 0,0,0, 0,0,0, 1,0,0, 0,0,
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         66.71 [deg]   Sun_angle= 5.8 [hr] (West of Sun)
MOON_POSTN:      320.73d {+21h 22m 56s}   -9.91d {-09d 54' 40"}
MOON_DIST:        91.77 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      299.13,-12.85 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      236.05,-62.96 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 109.20,-19.13 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:30:36 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      57
TRIGGER_NUM:     377422204
GRB_RA:          157.600d {+10h 30m 24s} (J2000),
                 157.687d {+10h 30m 45s} (current),
                 157.265d {+10h 29m 04s} (1950)
GRB_DEC:         -70.850d {-70d 50' 59"} (J2000),
                 -70.917d {-70d 55' 00"} (current),
                 -70.593d {-70d 35' 33"} (1950)
GRB_ERROR:       15.87 [deg radius, statistical plus systematic]
GRB_INTEN:       82 [cnts/sec]
DATA_SIGNIF:     7.60 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        16278 TJD;   352 DOY;   12/12/17
GRB_TIME:        27001.58 SOD {07:30:01.58} UT
GRB_PHI:          94.00 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.45
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      50%  Distant Particles
2nd_MOST_LIKELY:  49%  GRB
DETECTORS:       0,1,0, 0,0,0, 0,0,0, 1,0,0, 0,0,
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         73.52 [deg]   Sun_angle= 7.2 [hr] (West of Sun)
MOON_POSTN:      320.73d {+21h 22m 56s}   -9.91d {-09d 54' 39"}
MOON_DIST:        98.36 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      291.81,-11.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      220.72,-66.41 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 109.20,-19.13 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:31:55 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
POINT_ROLL:      119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26552.84 SOD {07:22:32.84} UT,   285.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.736
N_STARS:         190
X_OFFSET:        811 [pixels]
Y_OFFSET:        734 [pixels]
X_MAX:           1770 [pixels]
Y_MAX:           1693 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00542441000msufc0284.fits
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.75d {+21h 22m 59s}   -9.91d {-09d 54' 24"}
MOON_DIST:       107.02 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #14089
M. H. Siegel (PSU), B. N. Barlow (PSU), D. N. Burrows (PSU), M. M. Chester (PSU), V. D'Elia (ASDC), D. Grupe (PSU), N. P. M. Kuin (UCL-MSSL), C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team:
At 07:17:47 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 121217A (trigger=542441). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 153.724, -62.304 which is
```
   RA(J2000) = 10h 14m 54s
   Dec(J2000) = -62d 18' 13"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak with some substructure, with a duration of about 60 sec. The peak count rate was ~3200 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 07:18:51.8 UT, 64.0 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 153.70643, -62.35064 which is equivalent to:
```
   RA(J2000)  = 10h 14m 49.54s
   Dec(J2000) = -62d 21' 02.3"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 170 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 3.72 x 10^21 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 1.93e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 72 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 0.00% of the XRT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the large, but uncertain extinction expected.
Burst Advocate for this burst is M. H. Siegel (siegel AT astro.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:32:40 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     542441,   Seg_Num: 0
GRB_RA:          153.7095d {+10h 14m 50.27s} (J2000),
                 153.8146d {+10h 15m 15.50s} (current),
                 153.3048d {+10h 13m 13.14s} (1950)
GRB_DEC:         -62.3504d {-62d 21' 01.4"} (J2000),
                 -62.4151d {-62d 24' 54.4"} (current),
                 -62.1012d {-62d 06' 04.4"} (1950)
GRB_ERROR:       2.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26425.00 SOD {07:20:25.00} UT,   157.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.74 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.75d {+21h 23m 00s}   -9.90d {-09d 54' 15"}
MOON_DIST:       106.97 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.83, -4.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      201.49,-63.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
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 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:33:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
ROLL:            119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26552.84 SOD {07:22:32.84} UT,   285.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     377421762
X_OFFSET:        1131 [pixels]
Y_OFFSET:        1054 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1291
Y_GRB_POS:       1214
BINNING_INDEX:   1
IM_URL:          sw00542441000msuni0294.fits
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.76d {+21h 23m 02s}   -9.90d {-09d 54' 06"}
MOON_DIST:       107.03 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:32:31 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
POINT_ROLL:      119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26552.84 SOD {07:22:32.84} UT,   285.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.736
N_STARS:         190
X_OFFSET:        811 [pixels]
Y_OFFSET:        734 [pixels]
X_MAX:           1770 [pixels]
Y_MAX:           1693 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00542441000msufc0284.fits
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.75d {+21h 23m 00s}   -9.91d {-09d 54' 17"}
MOON_DIST:       107.02 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:33:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
ROLL:            119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  26552.84 SOD {07:22:32.84} UT,   285.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     377421762
X_OFFSET:        1131 [pixels]
Y_OFFSET:        1054 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1291
Y_GRB_POS:       1214
BINNING_INDEX:   1
IM_URL:          sw00542441000msuni0294.fits
SUN_POSTN:       265.39d {+17h 41m 33s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.76d {+21h 23m 03s}   -9.90d {-09d 54' 02"}
MOON_DIST:       107.03 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:36:49 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
POINT_ROLL:      119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  27133.36 SOD {07:32:13.36} UT,   865.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        0.865
N_STARS:         190
X_OFFSET:        571 [pixels]
Y_OFFSET:        494 [pixels]
X_MAX:           2010 [pixels]
Y_MAX:           1933 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00542441000msufc0865.fits
SUN_POSTN:       265.39d {+17h 41m 34s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.79d {+21h 23m 10s}   -9.89d {-09d 53' 29"}
MOON_DIST:       107.04 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 17 Dec 12 07:37:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
POINT_ROLL:      119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  27133.36 SOD {07:32:13.36} UT,   865.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        0.865
N_STARS:         190
X_OFFSET:        571 [pixels]
Y_OFFSET:        494 [pixels]
X_MAX:           2010 [pixels]
Y_MAX:           1933 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00542441000msufc0865.fits
SUN_POSTN:       265.39d {+17h 41m 34s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.79d {+21h 23m 11s}   -9.89d {-09d 53' 24"}
MOON_DIST:       107.04 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:39:31 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
ROLL:            119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  27133.36 SOD {07:32:13.36} UT,   865.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     377422343
X_OFFSET:        1130 [pixels]
Y_OFFSET:        1053 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1290
Y_GRB_POS:       1213
BINNING_INDEX:   1
IM_URL:          sw00542441000msuni0875.fits
SUN_POSTN:       265.39d {+17h 41m 34s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.82d {+21h 23m 16s}   -9.88d {-09d 52' 59"}
MOON_DIST:       107.05 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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:     Mon 17 Dec 12 07:39:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     542441,   Seg_Num: 0
POINT_RA:        153.698d {+10h 14m 48s} (J2000)
POINT_DEC:       -62.298d {-62d 17' 52"} (J2000)
ROLL:            119.614d
IMG_START_DATE:  16278 TJD;   352 DOY;   12/12/17
IMG_START_TIME:  27133.36 SOD {07:32:13.36} UT,   865.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     377422343
X_OFFSET:        1130 [pixels]
Y_OFFSET:        1053 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1290
Y_GRB_POS:       1213
BINNING_INDEX:   1
IM_URL:          sw00542441000msuni0875.fits
SUN_POSTN:       265.39d {+17h 41m 35s}  -23.37d {-23d 22' 09"}
SUN_DIST:         78.77 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      320.82d {+21h 23m 16s}   -9.88d {-09d 52' 56"}
MOON_DIST:       107.05 [deg]
MOON_ILLUM:      21 [%]
GAL_COORDS:      285.80, -4.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      201.39,-63.41 [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 #14090
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 2474 s of XRT Photon Counting mode data and 5 UVOT images for GRB 121217A, 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 = 153.70999, -62.35047 which is equivalent to:
```
RA (J2000): 10h 14m 50.40s
Dec (J2000): -62d 21' 01.7"
```
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 #14091
J. Elliott (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 121217A (Swift trigger 542441; Siegel et al., GCN 14089) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
Observations started on December 17, 2012, at 07:21 UT, 210 s after the GRB trigger. They were performed at an average seeing of 1.6" and at an average airmass of 1.2.
We found a fading point source at the border of the enhanced XRT error circle given in Evans et al. (GCN 14090)
```
RA (J2000.0) = 10:14:50.407
DEC (J2000.0) = -62:21:03.53
```
with an uncertainty of 0.5" in each coordinate.
Based on a total exposure time of 456 s in g'r'i'z' and 480 s in JHK, at a midtime of 1882 s after the burst, we estimate preliminary AB magnitudes of
```
g' = 20.3 +/- 0.1,
r' = 19.3 +/- 0.1,
i' = 18.9 +/- 0.1,
z' = 18.6 +/- 0.1,
J  = 18.1 +/- 0.1,
H  = 17.7 +/- 0.1,
K  = 17.4 +/- 0.1.
```
In the r' band the source faded with a decay slope of 0.7 +/- 0.1 between 2000 s and 4200 s after the trigger. The SED can be fit with a power-law with a slope of beta = 0.8 +/- 0.1.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E(B-V)= 0.38 mag in the direction of the burst (Schlegel et al. 1998).
The extinction-corrected SED suggests a photo-z of 3.0 +/- 0.2. We caution, however, that the high Galactic extinction along the line of sight might affect this result.
GCN Circular #14092
S. R. Oates (MSSL-UCL) and M. H. Siegel (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 121217A 73 s after the BAT trigger (Siegel et al., GCN Circ. 14089). A source consistent with the GROND optical position (Elliott et al. GCN Circ. 14091) is detected in the initial UVOT exposures. The preliminary UVOT position is:
```
    RA (J2000) = 10:14:50.32 = 153.7097  (deg)
   Dec (J2000) = -62:21:03.3 = -62.35096 (deg)
```
with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               73          222          147         19.58 +/- 0.13
v                  616         5906          313         19.01 +/- 0.22
b                  541          560          19          18.76 +/- 0.36
u                  285         6522          540         20.09 +/- 0.34
w1                 666         6317          313        >19.96
m2                 641         6112          313        >19.85
w2                 591         7138          510        >20.37
```
The magnitudes in the table are not corrected for the significant Galactic extinction due to the reddening of E(B-V) = 0.37 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #14093
P.A. Evans (U. Leicester), O.M. Littlejohns (U. Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), G. Stratta (ASDC), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester) and M.H. Siegel report on behalf of the Swift-XRT team:
We have analysed 7.1 ks of XRT data for GRB 121217A (Siegel et al. GCN Circ. 14089), from 70 s to 30.3 ks after the BAT trigger. The data comprise 655 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 14090).
The late-time light curve (from T0+5.5 ks) can be modelled with a power-law decay with a decay index of alpha=0.63 (+/-0.08).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.15 (+0.11, -0.08). The best-fitting absorption column is consistent with the Galactic value of 3.7 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.92 (+0.11, -0.10) and a best-fitting absorption column of 4.02 (+0.51, -0.30) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.6 x 10^-11 (7.3 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     4.02 (+0.51, -0.30) x 10^21 cm^-2
Galactic foreground: 3.7 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.92 (+0.11, -0.10)
```
If the light curve continues to decay with a power-law decay index of 0.52, the count rate at T+24 hours will be 0.091 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.2 x 10^-12 (6.7 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00542441.
This circular is an official product of the Swift-XRT team.
GCN Circular #14094
David Yu and David Gruber (both MPE) report on behalf of the Fermi GBM Team:
"At 07:30:01.58 UT on 17 December 2012, the Fermi Gamma-Ray Burst Monitor triggered and located a burst (trigger 377422204 / 121217313), whose location is consistent with the Swift GRB 121217A (Siegel et al. GCN 14089) which triggered BAT ~13 minutes prior to the GBM. Upon closer examination, we found that GRB 121217A is also present in the GBM data. GBM did not trigger on this earlier emission period owing to the triggering being disabled while Fermi was passing through a region of high geomagnetic latitude.
The GBM light curve consists of two epochs of emission, separated by an epoch of quiescence of about 700 s. The duration of the first pulse is about 50 s while the second pulse is about 30 s long. The overall event T90 is about 780 s (50-300 keV). The time-averaged spectrum of the first emission epoch, from T0-749.6 s to T0-704.5 s, is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.20 +/- 0.12 and the cutoff energy, parameterized as Epeak, is 264 +/- 75 keV. The time-averaged spectrum of the second emission epoch, from T0-8.2 s to T0+24.6 s, is well fit by the same model, having a power law index of -1.29 +/- 0.14 and an Epeak of 184 +/- 56 keV.
The event fluence (10-1000 keV) over the overall event is (1.11 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.68 s in the 10-1000 keV band is 3.47 +/- 0.29 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #14095
R. Ruffini, L. Izzo, G.B. Pisani, C.L. Bianco, on behalf of a larger collaboration, report:
GRB 121217A, following our theoretical considerations based on the Induced Gravitational Collapse scenario for GRBs-SNe, allows also for a different solution with a cosmological redshift of z=0.8 (+- 0.1). We base this result on a preliminary analysis of the superposition of the late X-ray afterglow emission, considering GRB 090618 as the prototype of the class. We have considered the first 75 ks of the X-ray afterglow light curve of GRB 121217A in this preliminary analysis. More details on the model will appear soon on the arXiv.
We also predict a presence of a SN emerging after about 18 (+- 3) days from the GRB trigger, e.g. in the first days of January 2013. Assuming an interstellar extinction obtained from the Schlegel et al. (1998) extinction map and a supernova emission similar to the 1998bw one, we estimate an observed magnitude of +24.5 (+- 0.5) in the J filter. We further notice that, given the galactic latitude less than 5 deg (-4.89 deg), the calculated extinction value can differ at least of 1 mag.
Follow-up photometric and possibly spectroscopical observations are strongly requested.
GCN Circular #14096
J. R. Cummings (GSFC/UMBC), T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), A. M. Parsons (GSFC), G. Sato (ISAS), M. H. Siegel (PSU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 121217A (trigger #542441) (Siegel, et al., GCN Circ. 14089). The BAT ground-calculated position is RA, Dec = 153.708, -62.354 deg, which is
```
   RA(J2000)  =  10h 14m 50.0s 
   Dec(J2000) = -62d 21' 15.5" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 99%.
The mask-weighted light curve shows two well-separated periods of emission. The first starts at ~T-110 sec with weak emission, then peaks at ~T+1 sec, and returns to baseline at ~T+80 sec. The second period of emission starts at ~T+500 sec, with weak peaks at ~T+500 and ~T+610 sec and the main peak at ~T+730 sec and returns to baseline out past T+960 sec (where the data ends). There are enough differences in the profiles of these two periods of emission to conclude they are not gravitationally lensed. T90 (15-350 keV) is 778 +- 16 sec (estimated error including systematics).
The time-averaged spectrum from T-17.7 to T+783.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.08. The fluence in the 15-150 keV band is 6.2 +- 0.3 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+735.96 sec in the 15-150 keV band is 1.8 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/542441/BA/
GCN Circular #14097
P. Hancock, T. Murphy, B. Gaensler, M. Bell, D. Burlon (University of Sydney/CAASTRO), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI)
We observed GRB121217A (GCN 14809) with the Australia Telescope Compact Array at 44GHz for 90 minutes centered on 12:55UT Dec 21 2012 (T0+4.234days) in poor weather.
We detect no radio source at the optical location of the GRB (GCN 14091) and place a 3sigma upper limit of 0.6mJy on the flux of an afterglow.
These observations were obtained as part of ATCA project C2689. We thank the observatory staff for their support and scheduling the observations. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.
GCN Report 410.1
GCN_Report 410.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_410_1.pdf by M.H. Siegel at PSU titled: "Swift Observations of GRB 121217A"
1312.4547 from 18 Dec 13
J. Elliott et al.: Prompt emission of GRB 121217A from gamma-rays to the NIR
The mechanism that causes the prompt-emission episode of gamma-ray bursts (GRBs) is still widely debated despite there being thousands of prompt detections. The favoured internal shock model relates this emission to synchrotron radiation. However, it does not always explain the spectral indices of the shape of the spectrum, often fit with empirical functions. Multi-wavelength observations are therefore required to help investigate the possible underlying mechanisms that causes the prompt emission. We present GRB 121217A, for which we were able to observe its near-infrared (NIR) emission during a secondary prompt-emission episode with the Gamma-Ray Burst Optical Near-infrared Detector (GROND) in combination with the Swift and Fermi satellites, covering an energy range of 0.001 keV to 100 keV. We determine a photometric redshift of z=3.1+/-0.1 with a line-of-sight extinction of A_V~0 mag, utilising the optical/NIR SED. From the afterglow, we determine a bulk Lorentz factor of Gamma~250 and an emission radius of R<10^18 cm. The prompt-emission broadband spectral energy distribution is well fit with a broken power law with b1=-0.3+/-0.1, b2=0.6+/-0.1 that has a break at E=6.6+/-0.9 keV, which can be interpreted as the maximum injection frequency. Self-absorption by the electron population below energies of E_a<6 keV suggest a magnetic field strength of B~10^5 G. However, all the best fit models underpredict the flux observed in the NIR wavelengths, which also only rebrightens by a factor of ~2 during the second prompt emission episode, in stark contrast to the X-ray emission, which rebrightens by a factor of ~100, suggesting an afterglow component is dominating the emission. We present GRB 121217A one of the few GRBs for which there are multi-wavelength observations of the prompt-emission period and show that it can be understood with a synchrotron radiation model.

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Jochen Greiner, last update: 18-Dec-2013 [Disclaimer]