Gamma-ray Burst 171222A

(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:     Fri 22 Dec 17 16:26:31 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     799669,   Seg_Num: 0
GRB_RA:          148.293d {+09h 53m 10s} (J2000),
                 148.561d {+09h 54m 15s} (current),
                 147.546d {+09h 50m 11s} (1950)
GRB_DEC:         +35.622d {+35d 37' 18"} (J2000),
                 +35.536d {+35d 32' 11"} (current),
                 +35.858d {+35d 51' 27"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=2162 [image_cnts]
TRIGGER_DUR:     80.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        18109 TJD;   356 DOY;   17/12/22
GRB_TIME:        59099.80 SOD {16:24:59.80} UT
GRB_PHI:           4.17 [deg]
GRB_THETA:        37.63 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    10.49 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +0  +0  +0 +63  +0 
SUN_POSTN:       271.11d {+18h 04m 26s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.26 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.40d {+21h 25m 35s}  -15.48d {-15d 28' 35"}
MOON_DIST:       158.94 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.91, 51.35 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      137.96, 21.37 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
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 = 125.07,-9.47 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 22 Dec 17 16:28:16 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     799669,   Seg_Num: 0
GRB_RA:          148.2770d {+09h 53m 06.47s} (J2000),
                 148.5448d {+09h 54m 10.75s} (current),
                 147.5300d {+09h 50m 07.20s} (1950)
GRB_DEC:         +35.6282d {+35d 37' 41.5"} (J2000),
                 +35.5430d {+35d 32' 34.6"} (current),
                 +35.8641d {+35d 51' 50.5"} (1950)
GRB_ERROR:       4.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       6.69e-09 [erg/cm2/sec]
GRB_SIGNIF:      12.96 [sigma]
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59269.50 SOD {16:27:49.50} UT,   169.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.63 237.20 261.57 243.55
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       271.11d {+18h 04m 26s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.27 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.41d {+21h 25m 39s}  -15.47d {-15d 28' 24"}
MOON_DIST:       158.94 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.90, 51.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      137.94, 21.37 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.88 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:     Fri 22 Dec 17 16:28:26 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     799669,   Seg_Num: 0
GRB_RA:          148.2770d {+09h 53m 06.4s} (J2000),
                 148.5448d {+09h 54m 10.7s} (current),
                 147.5300d {+09h 50m 07.2s} (1950)
GRB_DEC:         +35.6282d {+35d 37' 41.5"} (J2000),
                 +35.5430d {+35d 32' 34.6"} (current),
                 +35.8641d {+35d 51' 50.5"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       168 [cnts]
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59269.50 SOD {16:27:49.50} UT,   169.7 [sec] since BAT Trigger Time
CENTROID_X:      304.23,  raw= 304  [pixels]
CENTROID_Y:      232.30,  raw= 232  [pixels]
ROLL:            92.53 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -155.80
GRB_POS_XRT_Z:   -5.09
IMAGE_URL:       sw00799669000msxps_rw.img
SUN_POSTN:       271.11d {+18h 04m 26s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.27 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.41d {+21h 25m 39s}  -15.47d {-15d 28' 23"}
MOON_DIST:       158.94 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.90, 51.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      137.94, 21.37 [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:     Fri 22 Dec 17 16:28:30 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     799669,   Seg_Num: 0
GRB_RA:          148.2770d {+09h 53m 06.4s} (J2000),
                 148.5448d {+09h 54m 10.7s} (current),
                 147.5300d {+09h 50m 07.2s} (1950)
GRB_DEC:         +35.6282d {+35d 37' 41.5"} (J2000),
                 +35.5430d {+35d 32' 34.6"} (current),
                 +35.8641d {+35d 51' 50.5"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       168 [cnts]
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59269.50 SOD {16:27:49.50} UT,   169.7 [sec] since BAT Trigger Time
CENTROID_X:      304.23,  raw= 304  [pixels]
CENTROID_Y:      232.30,  raw= 232  [pixels]
ROLL:            92.53 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -155.80
GRB_POS_XRT_Z:   -5.09
IMAGE_URL:       sw00799669000msxps_rw.img
SUN_POSTN:       271.11d {+18h 04m 26s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.27 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.41d {+21h 25m 39s}  -15.47d {-15d 28' 22"}
MOON_DIST:       158.94 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.90, 51.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      137.94, 21.37 [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:     Fri 22 Dec 17 16:29:20 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     799669,   Seg_Num: 0
GRB_RA:          148.293d {+09h 53m 10s} (J2000),
                 148.561d {+09h 54m 15s} (current),
                 147.546d {+09h 50m 11s} (1950)
GRB_DEC:         +35.622d {+35d 37' 18"} (J2000),
                 +35.536d {+35d 32' 11"} (current),
                 +35.858d {+35d 51' 27"} (1950)
GRB_DATE:        18109 TJD;   356 DOY;   17/12/22
GRB_TIME:        59099.80 SOD {16:24:59.80} UT
TRIGGER_INDEX:   20000
GRB_PHI:           4.17 [deg]
GRB_THETA:        37.63 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     80.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    10.49 [sigma]
LC_URL:          sw00799669000msb.lc
SUN_POSTN:       271.11d {+18h 04m 27s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.26 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.42d {+21h 25m 41s}  -15.47d {-15d 28' 17"}
MOON_DIST:       158.94 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.91, 51.35 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      137.96, 21.37 [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 an image 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 = 125.07,-9.47 [deg].  
COMMENTS:        The 2nd packet (of 3) was missing in the lightcurve data stream.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 22 Dec 17 16:32:24 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.278d {+09h 53m 07s} (J2000)
POINT_DEC:       +35.671d {+35d 40' 15"} (J2000)
POINT_ROLL:      92.530d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59275.25 SOD {16:27:55.25} UT,   175.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.564
N_STARS:         35
X_OFFSET:        504 [pixels]
Y_OFFSET:        584 [pixels]
X_MAX:           1943 [pixels]
Y_MAX:           2023 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00799669000msufc0175.fits
SUN_POSTN:       271.11d {+18h 04m 27s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.45d {+21h 25m 47s}  -15.47d {-15d 27' 56"}
MOON_DIST:       158.90 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.83, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.41 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 22 Dec 17 16:32:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.278d {+09h 53m 07s} (J2000)
POINT_DEC:       +35.671d {+35d 40' 15"} (J2000)
POINT_ROLL:      92.530d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59275.25 SOD {16:27:55.25} UT,   175.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.564
N_STARS:         35
X_OFFSET:        504 [pixels]
Y_OFFSET:        584 [pixels]
X_MAX:           1943 [pixels]
Y_MAX:           2023 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00799669000msufc0175.fits
SUN_POSTN:       271.11d {+18h 04m 27s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.45d {+21h 25m 48s}  -15.47d {-15d 27' 55"}
MOON_DIST:       158.90 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.83, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.41 [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:     Fri 22 Dec 17 16:33:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.278d {+09h 53m 07s} (J2000)
POINT_DEC:       +35.671d {+35d 40' 15"} (J2000)
ROLL:            92.530d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59275.25 SOD {16:27:55.25} UT,   175.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     535652895
X_OFFSET:        965 [pixels]
Y_OFFSET:        1150 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1125
Y_GRB_POS:       1310
BINNING_INDEX:   1
IM_URL:          sw00799669000msuni0196.fits
SUN_POSTN:       271.11d {+18h 04m 27s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.46d {+21h 25m 49s}  -15.46d {-15d 27' 49"}
MOON_DIST:       158.90 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.83, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.41 [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:     Fri 22 Dec 17 16:33:40 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.278d {+09h 53m 07s} (J2000)
POINT_DEC:       +35.671d {+35d 40' 15"} (J2000)
ROLL:            92.530d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59275.25 SOD {16:27:55.25} UT,   175.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     535652895
X_OFFSET:        965 [pixels]
Y_OFFSET:        1150 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1125
Y_GRB_POS:       1310
BINNING_INDEX:   1
IM_URL:          sw00799669000msuni0196.fits
SUN_POSTN:       271.11d {+18h 04m 27s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.46d {+21h 25m 50s}  -15.46d {-15d 27' 48"}
MOON_DIST:       158.90 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.83, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.41 [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:        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:     Fri 22 Dec 17 16:42:33 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.277d {+09h 53m 06s} (J2000)
POINT_DEC:       +35.673d {+35d 40' 22"} (J2000)
POINT_ROLL:      92.528d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59975.49 SOD {16:39:35.49} UT,   875.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.309
N_STARS:         55
X_OFFSET:        405 [pixels]
Y_OFFSET:        590 [pixels]
X_MAX:           1844 [pixels]
Y_MAX:           2029 [pixels]
DET_THRESH:      5
PHOTO_THRESH:    2
SL_URL:          sw00799669000msufc0875.fits
SUN_POSTN:       271.12d {+18h 04m 29s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.53d {+21h 26m 08s}  -15.45d {-15d 26' 48"}
MOON_DIST:       158.91 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.82, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.42 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circluar #22265
J. L. Racusin (NASA/GSFC), A. Deich (PSU), S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the Swift Team:
At 16:24:59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 171222A (trigger=799669). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 148.293, +35.622 which is
```
   RA(J2000) = 09h 53m 10s
   Dec(J2000) = +35d 37' 18"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual with an image trigger, the BAT light curve does not show any significant features.
The XRT began observing the field at 16:27:49.5 UT, 169.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 148.27784, 35.62759 which is equivalent to:
```
   RA(J2000)  = 09h 53m 06.68s
   Dec(J2000) = +35d 37' 39.3"
```
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This location is 48 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. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density.
The initial flux in the 2.5 s image was 6.69e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 250 seconds with the U filter starting 175 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 19.2 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 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01.
Burst Advocate for this burst is J. L. Racusin (judith.racusin AT 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:     Fri 22 Dec 17 16:42:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.277d {+09h 53m 06s} (J2000)
POINT_DEC:       +35.673d {+35d 40' 22"} (J2000)
POINT_ROLL:      92.528d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59975.49 SOD {16:39:35.49} UT,   875.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.309
N_STARS:         55
X_OFFSET:        405 [pixels]
Y_OFFSET:        590 [pixels]
X_MAX:           1844 [pixels]
Y_MAX:           2029 [pixels]
DET_THRESH:      5
PHOTO_THRESH:    2
SL_URL:          sw00799669000msufc0875.fits
SUN_POSTN:       271.12d {+18h 04m 29s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.54d {+21h 26m 08s}  -15.45d {-15d 26' 46"}
MOON_DIST:       158.91 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.82, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.42 [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:     Fri 22 Dec 17 16:43:01 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     799669,   Seg_Num: 0
GRB_RA:          148.2778d {+09h 53m 06.67s} (J2000),
                 148.5456d {+09h 54m 10.94s} (current),
                 147.5308d {+09h 50m 07.39s} (1950)
GRB_DEC:         +35.6266d {+35d 37' 35.7"} (J2000),
                 +35.5414d {+35d 32' 28.8"} (current),
                 +35.8625d {+35d 51' 44.8"} (1950)
GRB_ERROR:       2.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59663.00 SOD {16:34:23.00} UT,   563.2 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       271.12d {+18h 04m 29s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.28 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.54d {+21h 26m 09s}  -15.45d {-15d 26' 45"}
MOON_DIST:       158.95 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.90, 51.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      137.94, 21.37 [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:     Fri 22 Dec 17 16:43:55 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.277d {+09h 53m 06s} (J2000)
POINT_DEC:       +35.673d {+35d 40' 22"} (J2000)
ROLL:            92.528d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59975.49 SOD {16:39:35.49} UT,   875.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     535653595
X_OFFSET:        964 [pixels]
Y_OFFSET:        1149 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1124
Y_GRB_POS:       1309
BINNING_INDEX:   1
IM_URL:          sw00799669000msuni0896.fits
SUN_POSTN:       271.12d {+18h 04m 29s}  -23.43d {-23d 25' 56"}
SUN_DIST:        129.29 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.54d {+21h 26m 11s}  -15.44d {-15d 26' 39"}
MOON_DIST:       158.91 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.82, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.42 [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:     Fri 22 Dec 17 16:44:09 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     799669,   Seg_Num: 0
POINT_RA:        148.277d {+09h 53m 06s} (J2000)
POINT_DEC:       +35.673d {+35d 40' 22"} (J2000)
ROLL:            92.528d
IMG_START_DATE:  18109 TJD;   356 DOY;   17/12/22
IMG_START_TIME:  59975.49 SOD {16:39:35.49} UT,   875.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     535653595
X_OFFSET:        964 [pixels]
Y_OFFSET:        1149 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1124
Y_GRB_POS:       1309
BINNING_INDEX:   1
IM_URL:          sw00799669000msuni0896.fits
SUN_POSTN:       271.12d {+18h 04m 29s}  -23.43d {-23d 25' 55"}
SUN_DIST:        129.29 [deg]   Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN:      321.55d {+21h 26m 11s}  -15.44d {-15d 26' 37"}
MOON_DIST:       158.91 [deg]
MOON_ILLUM:      17 [%]
GAL_COORDS:      188.82, 51.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      137.92, 21.42 [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 #22266
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 689 s of XRT Photon Counting mode data and 1 UVOT images for GRB 171222A, 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 = 148.27736, +35.62712 which is equivalent to:
```
RA (J2000): 09h 53m 6.57s
Dec (J2000): +35d 37' 37.6"
```
with an uncertainty of 3.0 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 #22269
D. A. Perley (LJMU), D. Malesani (DARK/NBI), K. Heintz (Univ. Iceland, DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), and J. J. Lehiten (MPS) report on behalf of a larger collaboration:
We obtained observations of GRB 171222A (Racusin et al., GCN 22265) using StanCam on the Nordic Optical Telescope, beginning at 00:08:31 UT on 2017-12-23. Imaging was obtained in both R and I bands.
In the raw images we identify an optical source, not visible in pre-imaging from Pan-STARRS, at the following location within the XRT error circle (Osborne et al. GCN 22266):
```
RA = 09:53:06.73
Dec = +35:37:35.5
```
We suggest that this source is the optical afterglow of GRB 171222A. Provisional photometry relative to nearby USNO stars gives a magnitude of R = 21.44 +/- 0.09 (at 7.67 hours after the GRB trigger).
GCN Circular #22271
V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and J.L. Racusin report on behalf of the Swift-XRT team:
We have analysed 8.1 ks of XRT data for GRB 171222A (Racusin et al. GCN Circ. 22265), from 176 s to 39.8 ks after the BAT trigger. The data comprise 386 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 22266).
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=2.05 (+0.39, -0.25). At T+285 s the decay steepens to an alpha of 4.51 (+0.43, -0.18). The light curve breaks again at T+533 s to a decay with alpha=7.78 (+0.22, -1.07), and again at T+712 s s to alpha=2.9 (+/-0.6), before a final break at T+2103 s s after which the decay index is 0.09 (+0.24, -0.27).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.28 (+/-0.04). The best-fitting absorption column is 6.2 (+/-0.8) x 10^20 cm^-2, in excess of the Galactic value of 1.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.99 (+0.15, -0.12) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.2 x 10^-11 (3.3 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.1 (+2.4, -0.0) x 10^20 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.99 (+0.15, -0.12)
```
If the light curve continues to decay with a power-law decay index of 0.09, the count rate at T+24 hours will be 0.021 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.7 x 10^-13 (7.0 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/00799669.
This circular is an official product of the Swift-XRT team.
GCN Circular #22272
A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), L. Izzo (HETH/IAA-CSIC), D.A. Kann (HETH/IAA-CSIC), C.C. Thoene (HETH/IAA-CSIC), D. A. Perley (LJMU), D. Malesani (DARK/NBI), K.E. Heintz (Univ. Iceland, DARK/NBI), D. Garcia (GTC) report on behalf of a larger collaboration,
We observed the afterglow of GRB 171222A (Racusin et al. GCN 22265; Osborne et al. GCN 22266; Perley et al. GCN 22269) using the 10.4m GTC telescope equipped with OSIRIS. Observations consisted of 3x900s exposures using grism R1000B, covering the range from 3700 to 7880 AA. The mean time of the combined spectrum is 3:11 UT (10.77 hr after the burst).
The combined spectrum shows a power-law continuum over the complete spectral range with several weak absorption features. We identify the strongest of them as Ly-alpha at a redshift of 2.409, with marginal detections of SiII, SiIV and CIV at the same redshift, which we identify as the redshift of the GRB. An intervening system at z=1.678 is also identified through the detection of MgII absorption.
GCN Circular #22273
N.Tyurina, V. Lipunov, E. Gorbovskoy,V.Kornilov, D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU
R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA), National University of San Juan, Argentina
H. Levato, C. Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina
D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, Irkutsk State University
V.Yurkov, Yu.Sergienko Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC (Tenerife) was pointed to the Swift GRB171222A (Racusin et al., GCN #22265;) 47159 seconds (~ 13h ) after trigger time at 2017-12-23 05:31:03 UT. The 5-sigma upper limit has been about 19.3 at single (180 s) and 20.9 at coadd (10x180 = 1800 s ) images.
We see OT detected by (Perley et al., GCN #22269; de Ugarte Postigo et al., GCN #22272 ) at X-ray position (Osborne et al., GCN #22266; D'Elia et al., GCN #22271).
The OT unfiltered magnitude is about ~ 21.
The observations made on zenit distance = 11 degrees, galaxy latitude b = 52 degree. The moon (21 % bright part) below the horizon (The altitude of the Moon is -73 degree ). The sun altitude is -30.5 degree. The object can be observed till sunrise at 2017-12-23 07:54:43 .
This message can be cited.
GCN Circular #22274
X. Zhang, P. Zong, J.H. Liu (XAO), H.X. Feng, Z.P. Zhu, D. Xu (NAOC), H.B. Niu, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report on behalf of a larger collaboration:
We observed the field of GRB 171222A (Racusin et al., GCN 22265) using the 1m telescope located at Nanshan, Xinjiang, China. We obtained 6x300s R-band frames, starting at 18:14:36 UT on 2017-12-22, i.e., 1.83 hr after the BAT trigger.
An uncatalogued and fading optical transient (OT) is detected at the XRT position (Osborne et al., GCN 22266) as well as the NOT position (Perley et al., GCN 22269) in our images. Preliminary photometry results are as follows:
```
Tmid-T0 Exposure  Filter    Mag(R)    MagErr(R)
(hr)           (s)
1.87        1x300       R        20.86        0.21
2.68        3x300       R        21.47        0.22
7.87        2x300       R        21.72        0.22
```
Photometry is calibrated with nearby USNO-B1.0 stars (R2 magnitudes), and errors are only statistical values. We thus conclude that this OT is the optical afterglow of GRB 171222A.
GCN Circular #22275
N. P. M. Kuin (UCL-MSSL) and J. L. Racusin (NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171222A 176 s after the BAT trigger (Racusin et al., GCN Circ. 22265). No optical afterglow consistent with the enhanced XRT position (Osborne et al. GCN Circ 22266) or the NOT position (Perley et al., GCN Circ 22269) is detected in the initial UVOT exposures. The optical afterglow was detected however by Perley et al. (GCN Circ 22269), Tyurina et al. (GCN Circ. 22273), and a redshift was reported by de Ugarte Postigo (GCN Circ. 22272). 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

 u_FC     176         426      246   >20.6
 u        176        1026      393   >20.3
 b        432        1795      175   >20.3
 v        482        1846      175   >19.2
 uvw1     531        1895      175   >19.4
 uvm2     506        1870      175   >19.3
 uvw2     458        1821      175   >19.6
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #22276
H.J. Tan (CCU), H.X. Feng, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School) report
We observed the field of GRB 171222A (Racusin et al., GCN 22265) using the 0.36m robotic telescope located at Nanshan, Xinjiang, China. Observations started at 17:04:17 UT on 2017-12-22, i.e., 39.3 mins after the BAT trigger, and all imaged were taken without filter.
No optical source is detected at the XRT position (Osborne et al., GCN 22266) as well as the NOT position (Perley et al., GCN 22269), down to a limiting magnitude of m(R)~19.3, calibrated with the USNO B1 field.
GCN Circular #22277
M. Stanbro (UAH), C. M. Hui (NASA/MSFC) and C. Meegan (UAH) reports on behalf of the Fermi GBM Team:
At 16:25:10.54 UT on 22 December 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 171222A (trigger 535652715/171222684) which was also detected by the Swift/BAT and XRT (Racusin et al. 2017, GCN 22265). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 43 degrees.
The GBM light curve shows a single peak with a duration (T90) of about 80.4s (50-300 keV). The time-averaged spectrum from T0+0.0s to T0+78.8s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.09+/- 0.27 and the cutoff energy, parameterized as Epeak, is 29.18 +/- 2.73 keV.
The event fluence (10-1000 keV) in this time interval is (2.27 +/- 0.13)E-06 erg/cm^2. The 1s peak photon flux measured starting from T0+60.1s in the 10-1000 keV band is 2.3 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog.
GCN Circular #22279
Y. Kitaoka, T. Sakamoto (AGU)
We observed the field of GRB 171222A detected by Swift (Racusin et al. GCN circ. 22265) with the 0.3 m AROMA-N telescope located at Aoyama Gakuin University (Sagamihara, Japan). Due to the introduction issue of the telescope, we only obtained one 120 sec image which contains the location of the GRB. The image was taken in the R filter starting from December 12 on 18:53:26 (UT) about 140 minutes after the trigger and stopped on 18:55:26 (UT). We do not detect the optical afterglow in this image at the location of the X-ray afterglow (Osborne et al. GCN circ. 22266). The estimated five sigma upper limit is ~15.3 using the USNO-B1 catalog.
GCN Circular #22280
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 171222A (trigger #799669) (Racusin, et al., GCN Circ. 22265). The BAT ground-calculated position is RA, Dec = 148.273, 35.624 deg which is
```
    RA(J2000)  =  09h 53m 05.4s
    Dec(J2000) = +35d 37' 24.9"
```
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%.
The mask-weighted light curve shows multiple overlapping peaks in three groupings. The first runs from approximately T-10 sec to T+50 sec, the second from T+50 sec to T+90 sec, and the third, weakest group from T+90 sec to T+200 sec. T90 (15-350 keV) is 174.8 +- 22.7 sec (estimated error including systematics).
The time-averaged spectrum from T+8.00 to T+209.82 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.07 +- 0.17. The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+61.34 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/799669/BA/

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Jochen Greiner, last update: 24-Dec-2017 [Disclaimer]