Gamma-ray Burst 141220A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:03:16 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.050d {+13h 00m 12s} (J2000),
                 195.228d {+13h 00m 55s} (current),
                 194.454d {+12h 57m 49s} (1950)
GRB_DEC:         +32.144d {+32d 08' 37"} (J2000),
                 +32.063d {+32d 03' 47"} (current),
                 +32.413d {+32d 24' 46"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4297 [cnts]    Image_Peak=374 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   154     E_range: 25-100 keV
BKG_INTEN:       16592 [cnts]
BKG_TIME:        21755.05 SOD {06:02:35.05} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17011 TJD;   354 DOY;   14/12/20
GRB_TIME:        21772.65 SOD {06:02:52.65} UT
GRB_PHI:         -153.98 [deg]
GRB_THETA:        50.81 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     48.20 [sigma]
IMAGE_SIGNIF:    15.59 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +4  +0  +0  -1  +0 
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 30"}
SUN_DIST:         88.98 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.33d {+16h 13m 19s}  -17.41d {-17d 24' 38"}
MOON_DIST:        67.59 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.68, 84.64 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      179.30, 35.14 [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 = 306.67,17.83 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=440748175).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:03:32 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      59
TRIGGER_NUM:     440748175
GRB_RA:          196.100d {+13h 04m 24s} (J2000),
                 196.278d {+13h 05m 07s} (current),
                 195.506d {+13h 02m 02s} (1950)
GRB_DEC:         +31.600d {+31d 36' 00"} (J2000),
                 +31.520d {+31d 31' 12"} (current),
                 +31.868d {+31d 52' 04"} (1950)
GRB_ERROR:       3.13 [deg radius, statistical only]
DATA_SIGNIF:     56.80 [sigma]
DATA_INTERVAL:   1.024 [sec]
GRB_DATE:        17011 TJD;   354 DOY;   14/12/20
GRB_TIME:        21772.49 SOD {06:02:52.49} UT
GRB_PHI:         302.00 [deg]
GRB_THETA:        48.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 30"}
SUN_DIST:         87.93 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
MOON_POSTN:      243.33d {+16h 13m 19s}  -17.41d {-17d 24' 39"}
MOON_DIST:        66.56 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       91.44, 84.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      180.58, 35.08 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2014/bn141220252/quicklook/glg_lc_medres34_bn141220252.gif
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=621915).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:03:24 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      47
TRIGGER_NUM:     440748175
GRB_RA:          189.833d {+12h 39m 20s} (J2000),
                 190.014d {+12h 40m 03s} (current),
                 189.230d {+12h 36m 55s} (1950)
GRB_DEC:         +38.650d {+38d 38' 60"} (J2000),
                 +38.568d {+38d 34' 05"} (current),
                 +38.925d {+38d 55' 28"} (1950)
GRB_ERROR:       4.95 [deg radius, statistical plus systematic]
GRB_INTEN:       1007 [cnts/sec]
DATA_SIGNIF:     37.40 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        17011 TJD;   354 DOY;   14/12/20
GRB_TIME:        21772.49 SOD {06:02:52.49} UT
GRB_PHI:         297.00 [deg]
GRB_THETA:        40.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.63
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       0,0,0, 1,1,0, 0,1,0, 0,0,0, 0,0,
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 30"}
SUN_DIST:         95.73 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      243.33d {+16h 13m 19s}  -17.41d {-17d 24' 39"}
MOON_DIST:        74.98 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      134.57, 78.20 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      170.70, 38.76 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2014/bn141220252/quicklook/glg_lc_medres34_bn141220252.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 338.72,25.62 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=621915).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:04:12 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     440748175
GRB_RA:          195.720d {+13h 02m 53s} (J2000),
                 195.899d {+13h 03m 36s} (current),
                 195.122d {+13h 00m 29s} (1950)
GRB_DEC:         +29.500d {+29d 30' 00"} (J2000),
                 +29.420d {+29d 25' 11"} (current),
                 +29.768d {+29d 46' 06"} (1950)
GRB_ERROR:       2.95 [deg radius, statistical only]
DATA_SIGNIF:     49.40 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        17011 TJD;   354 DOY;   14/12/20
GRB_TIME:        21772.49 SOD {06:02:52.49} UT
GRB_PHI:         301.00 [deg]
GRB_THETA:        50.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41531 (Gnd S/W Version number)
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 30"}
SUN_DIST:         87.20 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
MOON_POSTN:      243.34d {+16h 13m 21s}  -17.41d {-17d 24' 42"}
MOON_DIST:        65.47 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       76.88, 86.54 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      181.40, 33.06 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2014/bn141220252/quicklook/glg_lc_medres34_bn141220252.gif
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=621915).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:05:20 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.0647d {+13h 00m 15.5s} (J2000),
                 195.2428d {+13h 00m 58.2s} (current),
                 194.4690d {+12h 57m 52.5s} (1950)
GRB_DEC:         +32.1434d {+32d 08' 36.2"} (J2000),
                 +32.0630d {+32d 03' 46.6"} (current),
                 +32.4126d {+32d 24' 45.3"} (1950)
GRB_ERROR:       6.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       22 [cnts]
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21871.86 SOD {06:04:31.86} UT,   99.2 [sec] since BAT Trigger Time
CENTROID_X:      279.76,  raw= 280  [pixels]
CENTROID_Y:      293.64,  raw= 294  [pixels]
ROLL:            118.59 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -9.80
GRB_POS_XRT_Z:   -60.20
IMAGE_URL:       sw00621915000msxps_rw.img
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.97 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.35d {+16h 13m 24s}  -17.41d {-17d 24' 47"}
MOON_DIST:        67.60 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.55, 84.63 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.32, 35.15 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:05:29 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.0647d {+13h 00m 15.5s} (J2000),
                 195.2428d {+13h 00m 58.2s} (current),
                 194.4690d {+12h 57m 52.5s} (1950)
GRB_DEC:         +32.1434d {+32d 08' 36.2"} (J2000),
                 +32.0630d {+32d 03' 46.6"} (current),
                 +32.4126d {+32d 24' 45.3"} (1950)
GRB_ERROR:       6.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       22 [cnts]
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21871.86 SOD {06:04:31.86} UT,   99.2 [sec] since BAT Trigger Time
CENTROID_X:      279.76,  raw= 280  [pixels]
CENTROID_Y:      293.64,  raw= 294  [pixels]
ROLL:            118.59 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -9.80
GRB_POS_XRT_Z:   -60.20
IMAGE_URL:       sw00621915000msxps_rw.img
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.97 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.35d {+16h 13m 24s}  -17.41d {-17d 24' 47"}
MOON_DIST:        67.60 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.55, 84.63 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.32, 35.15 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:05:10 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.0647d {+13h 00m 15.52s} (J2000),
                 195.2428d {+13h 00m 58.27s} (current),
                 194.4690d {+12h 57m 52.56s} (1950)
GRB_DEC:         +32.1434d {+32d 08' 36.2"} (J2000),
                 +32.0630d {+32d 03' 46.6"} (current),
                 +32.4126d {+32d 24' 45.3"} (1950)
GRB_ERROR:       6.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       3.76e-10 [erg/cm2/sec]
GRB_SIGNIF:      4.69 [sigma]
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21871.86 SOD {06:04:31.86} UT,   99.2 [sec] since BAT Trigger Time
TAM[0-3]:        327.66 237.22 261.65 243.79
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.97 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.35d {+16h 13m 23s}  -17.41d {-17d 24' 46"}
MOON_DIST:        67.60 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.55, 84.63 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.32, 35.15 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.75 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:06:42 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.050d {+13h 00m 12s} (J2000),
                 195.228d {+13h 00m 55s} (current),
                 194.454d {+12h 57m 49s} (1950)
GRB_DEC:         +32.144d {+32d 08' 37"} (J2000),
                 +32.063d {+32d 03' 47"} (current),
                 +32.413d {+32d 24' 46"} (1950)
GRB_DATE:        17011 TJD;   354 DOY;   14/12/20
GRB_TIME:        21772.65 SOD {06:02:52.65} UT
TRIGGER_INDEX:   154
GRB_PHI:         -153.98 [deg]
GRB_THETA:        50.81 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     48.20 [sigma]
IMAGE_SIGNIF:    15.59 [sigma]
LC_URL:          sw00621915000msb.lc
SUN_POSTN:       268.11d {+17h 52m 26s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.98 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.36d {+16h 13m 27s}  -17.41d {-17d 24' 52"}
MOON_DIST:        67.62 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.68, 84.64 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      179.30, 35.14 [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 = 306.67,17.83 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:07:30 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.049d {+13h 00m 12s} (J2000)
POINT_DEC:       +32.154d {+32d 09' 14"} (J2000)
POINT_ROLL:      118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21877.90 SOD {06:04:37.90} UT,   105.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.045
N_STARS:         74
X_OFFSET:        552 [pixels]
Y_OFFSET:        568 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1527 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00621915000msufc0105.fits
SUN_POSTN:       268.11d {+17h 52m 27s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.98 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.37d {+16h 13m 29s}  -17.42d {-17d 24' 56"}
MOON_DIST:        67.63 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.73, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:08:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.049d {+13h 00m 12s} (J2000)
POINT_DEC:       +32.154d {+32d 09' 14"} (J2000)
POINT_ROLL:      118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21877.90 SOD {06:04:37.90} UT,   105.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.045
N_STARS:         74
X_OFFSET:        552 [pixels]
Y_OFFSET:        568 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1527 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00621915000msufc0105.fits
SUN_POSTN:       268.11d {+17h 52m 27s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.98 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.38d {+16h 13m 30s}  -17.42d {-17d 24' 58"}
MOON_DIST:        67.64 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.73, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:08:51 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.049d {+13h 00m 12s} (J2000)
POINT_DEC:       +32.154d {+32d 09' 14"} (J2000)
ROLL:            118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21877.90 SOD {06:04:37.90} UT,   105.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     440748290
X_OFFSET:        918 [pixels]
Y_OFFSET:        816 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1078
Y_GRB_POS:       976
BINNING_INDEX:   1
IM_URL:          sw00621915000msuni0118.fits
SUN_POSTN:       268.11d {+17h 52m 27s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.38d {+16h 13m 32s}  -17.42d {-17d 25' 01"}
MOON_DIST:        67.64 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.73, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:09:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.049d {+13h 00m 12s} (J2000)
POINT_DEC:       +32.154d {+32d 09' 14"} (J2000)
ROLL:            118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  21877.90 SOD {06:04:37.90} UT,   105.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     440748290
X_OFFSET:        918 [pixels]
Y_OFFSET:        816 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1078
Y_GRB_POS:       976
BINNING_INDEX:   1
IM_URL:          sw00621915000msuni0118.fits
SUN_POSTN:       268.11d {+17h 52m 27s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.39d {+16h 13m 33s}  -17.42d {-17d 25' 02"}
MOON_DIST:        67.64 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.73, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:15:33 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 11"} (J2000)
POINT_ROLL:      118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22090.42 SOD {06:08:10.42} UT,   317.8 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.583
N_STARS:         20
X_OFFSET:        598 [pixels]
Y_OFFSET:        496 [pixels]
X_MAX:           1557 [pixels]
Y_MAX:           1455 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00621915000msufc0317.fits
SUN_POSTN:       268.12d {+17h 52m 28s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.45d {+16h 13m 48s}  -17.42d {-17d 25' 29"}
MOON_DIST:        67.69 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:15:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 11"} (J2000)
POINT_ROLL:      118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22090.42 SOD {06:08:10.42} UT,   317.8 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.583
N_STARS:         20
X_OFFSET:        598 [pixels]
Y_OFFSET:        496 [pixels]
X_MAX:           1557 [pixels]
Y_MAX:           1455 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00621915000msufc0317.fits
SUN_POSTN:       268.12d {+17h 52m 28s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.45d {+16h 13m 49s}  -17.43d {-17d 25' 30"}
MOON_DIST:        67.69 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:16:47 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 11"} (J2000)
ROLL:            118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22090.42 SOD {06:08:10.42} UT,   317.8 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     440748503
X_OFFSET:        918 [pixels]
Y_OFFSET:        816 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1078
Y_GRB_POS:       976
BINNING_INDEX:   1
IM_URL:          sw00621915000msuni0330.fits
SUN_POSTN:       268.12d {+17h 52m 28s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.46d {+16h 13m 51s}  -17.43d {-17d 25' 34"}
MOON_DIST:        67.70 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:17:04 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 11"} (J2000)
ROLL:            118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22090.42 SOD {06:08:10.42} UT,   317.8 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     440748503
X_OFFSET:        918 [pixels]
Y_OFFSET:        816 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1078
Y_GRB_POS:       976
BINNING_INDEX:   1
IM_URL:          sw00621915000msuni0330.fits
SUN_POSTN:       268.12d {+17h 52m 28s}  -23.43d {-23d 25' 31"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.46d {+16h 13m 51s}  -17.43d {-17d 25' 35"}
MOON_DIST:        67.70 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #17196
J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 06:02:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 141220A (trigger=621915). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 195.050, +32.144 which is
```
   RA(J2000) = 13h 00m 12s
   Dec(J2000) = +32d 08' 37"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 10 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 06:04:31.8 UT, 99.2 seconds after the BAT trigger. The position determined from promptly downlinked data differs significantly from the on-board position, suggesting that the XRT may have centroided on a cosmic ray; the initial XRT position notice should be treated with caution. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 195.06735, 32.13361 which is equivalent to:
```
   RA(J2000)  = 13h 00m 16.16s
   Dec(J2000) = +32d 08' 01.0"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 64 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 1.33 x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 105 seconds after the BAT trigger. The 2.7'x2.7' sub-image shows a likely optical afterglow near the XRT position. We are unable to confirm or measure a magnitude due to the loss of star tracker lock.
We note that the XRT position may have an additional error of order 10 arcseconds due to star tracker lock. A more accurate location will be generated when the full dataset is available.
Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.nasa.gov). 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 20 Dec 14 06:34:55 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.0674d {+13h 00m 16.17s} (J2000),
                 195.2455d {+13h 00m 58.92s} (current),
                 194.4717d {+12h 57m 53.20s} (1950)
GRB_DEC:         +32.1330d {+32d 07' 58.8"} (J2000),
                 +32.0526d {+32d 03' 09.2"} (current),
                 +32.4022d {+32d 24' 07.9"} (1950)
GRB_ERROR:       3.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22073.00 SOD {06:07:53.00} UT,   300.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       268.13d {+17h 52m 32s}  -23.43d {-23d 25' 32"}
SUN_DIST:         88.98 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.64d {+16h 14m 34s}  -17.45d {-17d 26' 49"}
MOON_DIST:        67.80 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.49, 84.64 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.33, 35.14 [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:        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:     Sat 20 Dec 14 06:37:16 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 12"} (J2000)
POINT_ROLL:      118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22642.97 SOD {06:17:22.97} UT,   870.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.129
N_STARS:         190
X_OFFSET:        358 [pixels]
Y_OFFSET:        256 [pixels]
X_MAX:           1797 [pixels]
Y_MAX:           1695 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00621915000msufc0870.fits
SUN_POSTN:       268.13d {+17h 52m 32s}  -23.43d {-23d 25' 32"}
SUN_DIST:         89.00 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.66d {+16h 14m 39s}  -17.45d {-17d 26' 58"}
MOON_DIST:        67.85 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:37:37 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 12"} (J2000)
POINT_ROLL:      118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22642.97 SOD {06:17:22.97} UT,   870.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.129
N_STARS:         190
X_OFFSET:        358 [pixels]
Y_OFFSET:        256 [pixels]
X_MAX:           1797 [pixels]
Y_MAX:           1695 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00621915000msufc0870.fits
SUN_POSTN:       268.13d {+17h 52m 32s}  -23.43d {-23d 25' 32"}
SUN_DIST:         89.00 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.67d {+16h 14m 40s}  -17.45d {-17d 27' 00"}
MOON_DIST:        67.85 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:38:45 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 12"} (J2000)
ROLL:            118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22642.97 SOD {06:17:22.97} UT,   870.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     440749055
X_OFFSET:        917 [pixels]
Y_OFFSET:        815 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1077
Y_GRB_POS:       975
BINNING_INDEX:   1
IM_URL:          sw00621915000msuni0883.fits
SUN_POSTN:       268.13d {+17h 52m 32s}  -23.43d {-23d 25' 32"}
SUN_DIST:         89.00 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.68d {+16h 14m 43s}  -17.45d {-17d 27' 04"}
MOON_DIST:        67.86 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [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 20 Dec 14 06:38:56 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     621915,   Seg_Num: 0
POINT_RA:        195.046d {+13h 00m 11s} (J2000)
POINT_DEC:       +32.153d {+32d 09' 12"} (J2000)
ROLL:            118.590d
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22642.97 SOD {06:17:22.97} UT,   870.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     440749055
X_OFFSET:        917 [pixels]
Y_OFFSET:        815 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1077
Y_GRB_POS:       975
BINNING_INDEX:   1
IM_URL:          sw00621915000msuni0883.fits
SUN_POSTN:       268.14d {+17h 52m 32s}  -23.43d {-23d 25' 32"}
SUN_DIST:         89.00 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.68d {+16h 14m 43s}  -17.45d {-17d 27' 05"}
MOON_DIST:        67.86 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.75, 84.63 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      179.30, 35.15 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Dec 14 06:53:09 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     621915,   Seg_Num: 0
GRB_RA:          195.0677d {+13h 00m 16.24s} (J2000),
                 195.2458d {+13h 00m 58.99s} (current),
                 194.4720d {+12h 57m 53.27s} (1950)
GRB_DEC:         +32.1316d {+32d 07' 53.7"} (J2000),
                 +32.0512d {+32d 03' 04.2"} (current),
                 +32.4008d {+32d 24' 02.8"} (1950)
GRB_ERROR:       3.6 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17011 TJD;   354 DOY;   14/12/20
IMG_START_TIME:  22073.00 SOD {06:07:53.00} UT,   300.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       268.15d {+17h 52m 35s}  -23.43d {-23d 25' 32"}
SUN_DIST:         88.99 [deg]   Sun_angle= 4.9 [hr] (West of Sun)
MOON_POSTN:      243.82d {+16h 15m 17s}  -17.47d {-17d 28' 03"}
MOON_DIST:        67.94 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      102.48, 84.64 [deg] galactic lon,lat of the burst
ECL_COORDS:      179.33, 35.14 [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:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #17197
J. Gorosabel (IAA-CSIC/UPV-EHU), S. Hellmich (DLR), A. de Ugarte Postigo (IAA-CSIC), S. Mottola (DLR), C. Thoene (IAA-CSIC), report on behalf of a larger collaboration:
We observed the field of GRB 141220A with the 1.23m CAHA in the I-band starting ~8 min post burst. A bright afterglow is detected at RA(J2000)=13:00:15.76, DEC(J2000)=32:08:46:4 (+/-0.8"). We note an important discrepancy with the initial position reported by Swift.
GCN Circular #17198
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC), J. Gorosabel (UPV, IAA-CSIC), N. Tanvir (U. Leicester), J.P.U. Fynbo (DARK/NBI), P. Pesev (GRANTECAN), G. Gomez Velarde (GRANTECAN), and D. Perez Valladares (GRANTECAN) report on behalf of a larger collaboration
We observed the afterglow of GRB141220A (Cummings et al. GCN 17196, Gorosabel et al. GCN 17197) with OSIRIS at the 10.4m GTC. Observations began at 6:45 UT (50 min after the burst). In a first 600 s spectrum obtained with grism R1000B covering from 3750 to 7800 A we detect absorption features of AlII, FeII, MgII, MgI, at a redshift of 1.3195, including several absorptions of FeII* which make it very likely the redshift of the GRB. We also detect two MgII intervening systems at redshifts of 1.280 and 0.527.
GCN Circular #17199
C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana) on behalf of a larger collaboration report:
The 2-m Liverpool Telescope automatically began observing Swift GRB 141220A (Cummings et al. GCN 17196) on Dec 20 at 06:04:57 UT (125 sec after the burst trigger). The robotic LT-TRAP pipeline identified the optical afterglow at the position reported by Gorosabel et al. (GCN 17197) with r=18.6 +- 0.1 mag at 34 minutes after the GRB, calibrated against nearby SDSS-R stars.
GCN Circular #17200
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC), J. Gorosabel (IAA-CSIC, UPV-EHU), N.R. Tanvir (U. Leicester), J.P.U. Fynbo (DARK/NBI), P. Pesev (GRANTECAN), G. Gomez Velarde (GRANTECAN), and D. Perez Valladares (GRANTECAN) report on behalf of a larger collaboration:
Photometric observations of the afterglow of GRB 141220A (Cummings et al. GCN 17196, Gorosabel et al. GCN 17197, de Ugarte Postigo et al. GCN 17198) were obtained by OSIRIS/GTC starting 20.6 min after the GRB onset. The afterglow was detected at r' = 18.11+/-0.05 mag in the first image and had decayed by 0.6+/-0.1 mag 38.7 min after the burst. Using our photometric data we derive a decay slope of alpha=0.96+/-0.11 (where F_nu ~ t^-alpha). These results are consistent with the observations reported by Guidorzi et al. (GCN 17199). Our photometry was performed using SDSS stars as reference.
We encourage further observations and in particular spectroscopy of the afterglow, in particular to check for possible variability of the FeII* features between 5400 and 6100 A.
GCN Circular #17201
F. E. Marshall (NASA/GSFC) and J. R. Cummings (NASA/UMBC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 141220A 597 s after the BAT trigger (Cummings et al., GCN Circ. 17196). There were also other exposures when the spacecraft attitude was not stable. A source consistent with the optical position Gorosabel et al. (GCN Circ. 17197) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
    RA  (J2000) =3D  13:00:15.76 =3D 195.06565 (deg.)
    Dec (J2000) =3D +32:08:47.0  =3D  32.14639 (deg.)
```
with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence).
Preliminary detections 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             597          617           19         17.30 =B1 0.07
v                 647          839           39         17.65 =B1 0.16
b                 573          593           20         17.58 =B1 0.13
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) =3D 0.01 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #17202
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings, N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-61 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 141220A (trigger #621915) (Cummings, et al., GCN Circ. 17196). The BAT ground-calculated position is RA, Dec = 195.058, 32.146 deg which is:
```
    RA(J2000)  =  13h 00m 14.0s
    Dec(J2000) = +32d 08' 46.4"
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 19%.
The mask-weighted light curve shows two peaks at about T+1 and T+3 seconds, with an exponential decline noticeable out to ~T+20 seconds. T90 (15-350 keV) is 7.21 +- 0.48 sec (estimated error including systematics).
The time-averaged spectrum from T-0.91 to T+7.30 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.62 +- 0.38, and Epeak of 117.4 +- 45.1 keV (chi squared 56.50 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 2.6 +- 0.1 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T-0.13 sec in the 15-150 keV band is 8.9 +- 0.7 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.30 +- 0.08 (chi squared 67.35 for 57 d.o.f.). 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/621915/BA/
GCN Circular #17203
B.P. Gompertz (U. Leicester), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and J.R. Cummings report on behalf of the Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 141220A (Cummings et al. GCN Circ. 17196), from 87 s to 36.3 ks after the BAT trigger. The data comprise 42 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 195.0653, +32.1466 which is equivalent to:
```
RA (J2000): 13 00 15.66
Dec(J2000): +32 08 47.9
```
with an uncertainty of 3.6 arcsec (radius, 90% confidence).
The late-time light curve (from T0+5.6 ks) can be modelled with a power-law decay with a decay index of alpha=1.38 (+0.26, -0.23).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.81 (+0.21, -0.20). The best-fitting absorption column is 8.3 (+5.9, -5.1) x 10^20 cm^-2, in excess of the Galactic value of 1.3 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     8.3 (+5.9, -5.1) x 10^20 cm^-2
Galactic foreground: 1.3 x 10^20 cm^-2
Excess significance: 2.3 sigma
Photon index:	     1.81 (+0.21, -0.20)
```
If the light curve continues to decay with a power-law decay index of 1.38, the count rate at T+24 hours will be 2.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.5 x 10^-14 (1.1 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00621915.
This circular is an official product of the Swift-XRT team.
GCN Circular #17204
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of MITSuME and OISTER collaboration:
We observed the field of GRB 141220A (Cummings et al., GCNC 17196) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2014-12-20 16:27:31 UT (~10.4 h after the burst) We could not detect the previously reported afterglow (Cummings et al., GCNC 17196; Gorosabel et al., GCNC 17197; de Ugarte Postigo et al., GCNC 17198) in all the three bands.
Three sigma upper limits of the OT are listed below. We used SDSS-DR7 catalog for flux calibration.
```
#T0+[day]  MID-UT    T-EXP[sec]   g'     Rc     Ic
-----------------------------------------------------
0.47547    17:27:32    5940.0   >19.8  >19.9  >19.0
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
```
GCN Circular #17205
H.-F. Yu (MPE) reports on behalf of the Fermi GBM Team:
"At 06:02:52.49 UT on 20 Dec 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 141220A (trigger 141220252/ 141220252), which was also detected by Swift (Cummings et al. 2014, GCN 17196). The GBM on-ground location, using the Fermi GBM trigger data, is consistent with the Swift location. The trigger resulted in an Autonomous Repoint Request (ARR) that was accepted and the spacecraft slewed to the GBM in-flight location. The angle from the Fermi LAT boresight is about 47 degrees.
The GBM light curve consists of two main pulses with a duration (T90) of about 7.6 s (50-300 keV). The time-averaged spectrum from T0-1.920 s to T0+8.320 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.80 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 180 +/- 9 keV.
The event fluence (8-1000 keV) in this time interval is (5.23 +/- 0.15)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+0.128 s in the 8-1000 keV band is 12.0 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #17207
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline on behalf of the Konus-Wind team, report:
The long-duration GRB 141220A (Swift-BAT trigger #621915: Cummings et al., GCN 17196; Stamatikos et al., GCN 17202; Fermi-GBM observation: Yu, GCN 17205) triggered Konus-Wind at T0=21771.666 s UT (06:02:51.666).
The KW light curve shows a single emission episode lasting from ~T0-0.5 s to ~T0+7.5 s. The emission in this episode is visible up to ~4 MeV.
As observed by Konus-Wind, the burst had a fluence of 4.7(-0.4,+0.5)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0, of 2.2(-0.4,+0.5)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -0.55(-0.26,+0.30), and the peak energy Ep = 139(-14,+18) keV, chi2 = 83/98 dof. Fitting this spectrum with the Band model yields the same values of alpha and Ep and an upper limit on beta of -2.0
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB141220_T21771/
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #17215
Y. Yano, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, S. Kurita, Y. Ono, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 141220A (J. R. Cummings et al., GCN Circular #17196) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2014-12-20 15:16:22 UT (~9.2 h after the burst). We did not find any new point source within the refined XRT error circle (B. P. Gompertz., GCN Circular #17203) in all the three bands.
The measured magnitudes are listed below.
```
T0+[sec]     MID-UT    T-EXP[sec]        g'         Rc        Ic
-----------------------------------------------------------------------------
36707        18:07:29        8460          >21.4  >20.8  >20.4
-----------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used GSC2.3 catalog for flux calibration.
GCN Circular #17653
J. Mao, B. Lun and J.-M. Bai (YNAO) report:
We observed the field of GRB 141220A (Cummings et al., GCN 17196) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatory. Observations began from UT 22:28:38.1 20, Dec., 2014 (about 18.4 hours after the trigger). We did not detect the optical counterpart down to a limit of r'~21.0.
We thank Dr. A., de Ugarte Postigo for his kind suggestion and disucssion. J. Mao apologizes for this very later GCN circular submission.

Back to JG's homepage

Jochen Greiner, last update: 29-Mar-2015 [Disclaimer]