Gamma-ray Burst 171212A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 11:58:00 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     796778,   Seg_Num: 0
GRB_RA:          293.900d {+19h 35m 36s} (J2000),
                 294.096d {+19h 36m 23s} (current),
                 293.355d {+19h 33m 25s} (1950)
GRB_DEC:         +20.568d {+20d 34' 06"} (J2000),
                 +20.609d {+20d 36' 33"} (current),
                 +20.457d {+20d 27' 25"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       12410 [cnts]    Image_Peak=298 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   291     E_range: 15-50 keV
BKG_INTEN:       108961 [cnts]
BKG_TIME:        42987.85 SOD {11:56:27.85} UT
BKG_DUR:         40 [sec]
GRB_DATE:        18099 TJD;   346 DOY;   17/12/12
GRB_TIME:        43041.68 SOD {11:57:21.68} UT
GRB_PHI:         -107.35 [deg]
GRB_THETA:        24.14 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.48 [sigma]
IMAGE_SIGNIF:    7.35 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +1  -3  +0  +1 -57  +0 
SUN_POSTN:       259.83d {+17h 19m 19s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.02 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.86d {+13h 07m 27s}   -2.39d {-02d 23' 34"}
MOON_DIST:        97.61 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.16,  0.04 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      300.44, 41.52 [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 = 73.09,2.20 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 11:59:17 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     796778,   Seg_Num: 0
GRB_RA:          293.9196d {+19h 35m 40.70s} (J2000),
                 294.1152d {+19h 36m 27.65s} (current),
                 293.3746d {+19h 33m 29.90s} (1950)
GRB_DEC:         +20.5933d {+20d 35' 35.8"} (J2000),
                 +20.6340d {+20d 38' 02.2"} (current),
                 +20.4816d {+20d 28' 53.8"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.28e-08 [erg/cm2/sec]
GRB_SIGNIF:      14.73 [sigma]
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43132.75 SOD {11:58:52.75} UT,   91.1 [sec] since BAT Trigger Time
TAM[0-3]:        327.68 237.22 261.67 243.36
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       259.83d {+17h 19m 19s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.05 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.87d {+13h 07m 30s}   -2.40d {-02d 23' 48"}
MOON_DIST:        97.62 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the burst
ECL_COORDS:      300.47, 41.54 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.84 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 11:59:31 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     796778,   Seg_Num: 0
GRB_RA:          293.9196d {+19h 35m 40.7s} (J2000),
                 294.1152d {+19h 36m 27.6s} (current),
                 293.3746d {+19h 33m 29.9s} (1950)
GRB_DEC:         +20.5933d {+20d 35' 35.8"} (J2000),
                 +20.6340d {+20d 38' 02.2"} (current),
                 +20.4816d {+20d 28' 53.8"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       217 [cnts]
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43132.75 SOD {11:58:52.75} UT,   91.1 [sec] since BAT Trigger Time
CENTROID_X:      320.72,  raw= 321  [pixels]
CENTROID_Y:      298.90,  raw= 299  [pixels]
ROLL:            219.08 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   1.19
GRB_POS_XRT_Z:   33.76
IMAGE_URL:       sw00796778000msxps_rw.img
SUN_POSTN:       259.83d {+17h 19m 19s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.05 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.88d {+13h 07m 30s}   -2.40d {-02d 23' 50"}
MOON_DIST:        97.62 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the burst
ECL_COORDS:      300.47, 41.54 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 11:59:29 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     796778,   Seg_Num: 0
GRB_RA:          293.9196d {+19h 35m 40.7s} (J2000),
                 294.1152d {+19h 36m 27.6s} (current),
                 293.3746d {+19h 33m 29.9s} (1950)
GRB_DEC:         +20.5933d {+20d 35' 35.8"} (J2000),
                 +20.6340d {+20d 38' 02.2"} (current),
                 +20.4816d {+20d 28' 53.8"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       217 [cnts]
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43132.75 SOD {11:58:52.75} UT,   91.1 [sec] since BAT Trigger Time
CENTROID_X:      320.72,  raw= 321  [pixels]
CENTROID_Y:      298.90,  raw= 299  [pixels]
ROLL:            219.08 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   1.19
GRB_POS_XRT_Z:   33.76
IMAGE_URL:       sw00796778000msxps_rw.img
SUN_POSTN:       259.83d {+17h 19m 19s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.05 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.88d {+13h 07m 30s}   -2.40d {-02d 23' 50"}
MOON_DIST:        97.62 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the burst
ECL_COORDS:      300.47, 41.54 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:01:11 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     796778,   Seg_Num: 0
GRB_RA:          293.900d {+19h 35m 36s} (J2000),
                 294.096d {+19h 36m 23s} (current),
                 293.355d {+19h 33m 25s} (1950)
GRB_DEC:         +20.568d {+20d 34' 06"} (J2000),
                 +20.609d {+20d 36' 33"} (current),
                 +20.457d {+20d 27' 25"} (1950)
GRB_DATE:        18099 TJD;   346 DOY;   17/12/12
GRB_TIME:        43041.68 SOD {11:57:21.68} UT
TRIGGER_INDEX:   291
GRB_PHI:         -107.35 [deg]
GRB_THETA:        24.14 [deg]
DELTA_TIME:      58.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.48 [sigma]
IMAGE_SIGNIF:    7.35 [sigma]
LC_URL:          sw00796778000msb.lc
SUN_POSTN:       259.83d {+17h 19m 19s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.02 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.89d {+13h 07m 33s}   -2.40d {-02d 24' 08"}
MOON_DIST:        97.59 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.16,  0.04 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      300.44, 41.52 [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 = 73.09,2.20 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:01:54 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.585d {+20d 35' 07"} (J2000)
POINT_ROLL:      219.075d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43140.84 SOD {11:59:00.84} UT,   99.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.690
N_STARS:         157
X_OFFSET:        608 [pixels]
Y_OFFSET:        456 [pixels]
X_MAX:           1567 [pixels]
Y_MAX:           1415 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00796778000msufc0099.fits
SUN_POSTN:       259.83d {+17h 19m 19s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.90d {+13h 07m 35s}   -2.40d {-02d 24' 16"}
MOON_DIST:        97.60 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.18,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:02:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.585d {+20d 35' 07"} (J2000)
POINT_ROLL:      219.075d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43140.84 SOD {11:59:00.84} UT,   99.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.690
N_STARS:         157
X_OFFSET:        608 [pixels]
Y_OFFSET:        456 [pixels]
X_MAX:           1567 [pixels]
Y_MAX:           1415 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00796778000msufc0099.fits
SUN_POSTN:       259.83d {+17h 19m 20s}  -23.11d {-23d 06' 24"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.90d {+13h 07m 36s}   -2.41d {-02d 24' 19"}
MOON_DIST:        97.59 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.18,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:03:41 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.585d {+20d 35' 07"} (J2000)
ROLL:            219.075d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43140.84 SOD {11:59:00.84} UT,   99.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     534772760
X_OFFSET:        746 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       906
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw00796778000msuni0120.fits
SUN_POSTN:       259.83d {+17h 19m 20s}  -23.11d {-23d 06' 25"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.91d {+13h 07m 38s}   -2.41d {-02d 24' 35"}
MOON_DIST:        97.58 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.18,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:03:55 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.585d {+20d 35' 07"} (J2000)
ROLL:            219.075d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43140.84 SOD {11:59:00.84} UT,   99.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     534772760
X_OFFSET:        746 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       906
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw00796778000msuni0120.fits
SUN_POSTN:       259.83d {+17h 19m 20s}  -23.11d {-23d 06' 25"}
SUN_DIST:         55.03 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.91d {+13h 07m 39s}   -2.41d {-02d 24' 37"}
MOON_DIST:        97.58 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.18,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:09:05 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.589d {+20d 35' 19"} (J2000)
POINT_ROLL:      219.076d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43298.83 SOD {12:01:38.83} UT,   257.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.951
N_STARS:         49
X_OFFSET:        426 [pixels]
Y_OFFSET:        571 [pixels]
X_MAX:           1385 [pixels]
Y_MAX:           1530 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00796778000msufc0257.fits
SUN_POSTN:       259.84d {+17h 19m 21s}  -23.11d {-23d 06' 26"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.95d {+13h 07m 49s}   -2.43d {-02d 25' 32"}
MOON_DIST:        97.55 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:09:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.589d {+20d 35' 19"} (J2000)
POINT_ROLL:      219.076d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43298.83 SOD {12:01:38.83} UT,   257.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.951
N_STARS:         49
X_OFFSET:        426 [pixels]
Y_OFFSET:        571 [pixels]
X_MAX:           1385 [pixels]
Y_MAX:           1530 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00796778000msufc0257.fits
SUN_POSTN:       259.84d {+17h 19m 21s}  -23.11d {-23d 06' 26"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.96d {+13h 07m 49s}   -2.43d {-02d 25' 34"}
MOON_DIST:        97.55 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:10:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.589d {+20d 35' 19"} (J2000)
ROLL:            219.076d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43298.83 SOD {12:01:38.83} UT,   257.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     534772918
X_OFFSET:        746 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       906
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw00796778000msuni0278.fits
SUN_POSTN:       259.84d {+17h 19m 21s}  -23.11d {-23d 06' 26"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.97d {+13h 07m 52s}   -2.43d {-02d 25' 47"}
MOON_DIST:        97.54 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:10:42 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     796778,   Seg_Num: 0
POINT_RA:        293.913d {+19h 35m 39s} (J2000)
POINT_DEC:       +20.589d {+20d 35' 19"} (J2000)
ROLL:            219.076d
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43298.83 SOD {12:01:38.83} UT,   257.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     534772918
X_OFFSET:        746 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       906
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw00796778000msuni0278.fits
SUN_POSTN:       259.84d {+17h 19m 21s}  -23.11d {-23d 06' 26"}
SUN_DIST:         55.04 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      196.97d {+13h 07m 52s}   -2.43d {-02d 25' 49"}
MOON_DIST:        97.54 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      300.46, 41.53 [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 Circular #22243
A. Tohuvavohu (PSU), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), A. Deich (PSU), S. W. K Emery (UCL-MSSL), P. A. Evans (U Leicester), J.D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 11:57:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 171212A (trigger=796778). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 293.900, +20.568 which is
```
   RA(J2000) = 19h 35m 36s
   Dec(J2000) = +20d 34' 06"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 120 sec. The peak count rate was ~800 counts/sec (15-350 keV), at ~90 sec after the trigger.
The XRT began observing the field at 11:58:52.7 UT, 91.0 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 293.91826, 20.59159 which is equivalent to:
```
   RA(J2000)  = 19h 35m 40.38s
   Dec(J2000) = +20d 35' 29.7"
```
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 104 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 1.23 x 10^22 cm^-2 (Willingale et al. 2013).
The initial flux in the 2.5 s image was 1.28e-08 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 99 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 typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain, extinction expected.
Because this event is very close to the Galactic plane (lat=0.03 degrees) it is possibly a Galactic transient, in which case it takes the name 'Swift J1935.7+2036'.
Burst Advocate for this burst is A. Tohuvavohu (aaronb AT swift.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:     Tue 12 Dec 17 12:25:32 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     796778,   Seg_Num: 0
GRB_RA:          293.9181d {+19h 35m 40.34s} (J2000),
                 294.1137d {+19h 36m 27.29s} (current),
                 293.3731d {+19h 33m 29.54s} (1950)
GRB_DEC:         +20.5915d {+20d 35' 29.3"} (J2000),
                 +20.6322d {+20d 37' 55.7"} (current),
                 +20.4798d {+20d 28' 47.4"} (1950)
GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18099 TJD;   346 DOY;   17/12/12
IMG_START_TIME:  43488.00 SOD {12:04:48.00} UT,   446.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       259.85d {+17h 19m 24s}  -23.11d {-23d 06' 29"}
SUN_DIST:         55.03 [deg]   Sun_angle= -2.3 [hr] (East of Sun)
MOON_POSTN:      197.09d {+13h 08m 21s}   -2.47d {-02d 28' 26"}
MOON_DIST:        97.44 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       56.19,  0.03 [deg] galactic lon,lat of the burst
ECL_COORDS:      300.46, 41.53 [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 0.11% < P(seren) < 0.58%.

GCN Circular #22245
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1519 s of XRT Photon Counting mode data and 4 UVOT images for GRB 171212A, 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 = 293.91782, +20.59204 which is equivalent to:
```
RA (J2000): 19h 35m 40.28s
Dec (J2000): +20d 35' 31.3"
```
with an uncertainty of 2.3 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 #22246
E. Mazaeva (IKI), A. Pozanenko (IKI), I. Reva (FAPHI), M. Krugov (FAPHI), A. Kusakin (FAPHI), A. Volnova (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 171212A (Tohuvavohu et al., GCN 22243) with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on Dec. 12 (UT) 12:21:15. We took several images in R-filter. Within enhanced Swift-XRT error circle (Evans et al. GCN 22245) we do not detect any object. Preliminary photometry of initial combined images is following.
```
Date        UT start    t-T0  Filter Exp.   OT   Err. ULim
                      (mid, days)     (s)

2017-12-12  12:21:15 0.01896  R      3*120  n/d  n/d  20.0
2017-12-12  12:21:15 0.02728  R     13*120  n/d  n/d  21.1
```
The photometry is based on several nearby USNO-B1.0 stars
USNO-B.1_id R2
```
1105-0415742 17.60
1105-0415769 17.54
1105-0415805 16.38
1106-0408959 17.07
1105-0415666 16.91
```
GCN Circular #22248
A. A. Breeveld (UCL-MSSL) and A. Tohuvavohu (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171212A 99 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22243). No optical afterglow consistent with the enhanced XRT position (Evans et al., GCN Circ. 22245) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            99          249          147         >20.3
u_FC               257          507          246         >19.8
white               99         5510          383         >20.8
v                  588         5921          235         >19.0
b                  513         6581          275         >20.1
u                  257         6536          468         >20.1
w1                 638         6331          236         >19.5
m2                5926         6125          197         >19.3
w2                 738         5716          216         >19.5
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 7.95 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #22251
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester) and A. Tohuvavohu report on behalf of the Swift-XRT team:
We have analysed 5.7 ks of XRT data for GRB 171212A (Tohuvavohu et al. GCN Circ. 22243), from 81 s to 29.5 ks after the BAT trigger. The data comprise 347 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 enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 22245).
The late-time light curve (from T0+5.1 ks) can be modelled with a power-law decay with a decay index of alpha=1.2 (+0.4, -0.3).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.83 (+/-0.08). The best-fitting absorption column is 4.73 (+0.23, -0.22) x 10^22 cm^-2, in excess of the Galactic value of 1.2 x 10^22 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 8.1 x 10^-11 (1.9 x 10^-10) erg cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
```
Total column:	     4.73 (+0.23, -0.22) x 10^22 cm^-2
Galactic foreground: 1.2 x 10^22 cm^-2
Excess significance: 26.2 sigma
Photon index:	     1.83 (+/-0.08)
```
If the light curve continues to decay with a power-law decay index of 1.2, the count rate at T+24 hours will be 1.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-13 (2.8 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/00796778.
This circular is an official product of the Swift-XRT team.
GCN Circular #22253
```
TITLE:   GCN CIRCULAR
NUMBER:  22253 
SUBJECT: GRB 171212A/Swift J1935.7+2036: Swift-BAT refined analysis 
DATE:    17/12/13 13:56:37 GMT
FROM:    Amy Lien at GSFC  
```
A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), A. Tohuvavohu (PSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+1004 sec from the recent telemetry downlink, we report further analysis of BAT GRB 171212A (trigger #796778) (Tohuvavohu et al., GCN Circ. 22243). The BAT ground-calculated position is RA, Dec = 293.920, 20.597 deg which is
```
  RA(J2000)  =  19h 35m 40.8s
  Dec(J2000) = +20d 35' 49.6"
```
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~ T-30 s and ends at ~T+100 s, with some weak emissions lasting till ~ T+370 s. T90 (15-350 keV) is 320 +- 72 sec (estimated error including systematics).
The time-averaged spectrum from T-28.82 to T+371.18 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.23 +- 0.14. The fluence in the 15-150 keV band is 3.4 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+90.68 sec in the 15-150 keV band is 0.7 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/796778/BA/
GCN Circular #22285
K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration:
The long-duration GRB 171212A (Konus-Wind trigger time on 22:53:41.759) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 22:53:37.68 on 12 December 2017. The burst signal was seen only by the SGM instrument.
The light curve of the SGM shows two weak pulses. The emission starts at T0, peaks at T+0.5 sec and ends at T+30 sec. The T90 duration measured by the SGM data is 27.2 +- 3.6 sec (40-1000 keV). The T50 duration measured by the SGM data is 18.1 +- 4.5 sec (40-1000 keV).
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1197154263/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.

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Jochen Greiner, last update: 26-Dec-2017 [Disclaimer]