Gamma-ray Burst 170208B

(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:     Wed 08 Feb 17 22:33:54 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.155d {+08h 28m 37s} (J2000),
                 127.362d {+08h 29m 27s} (current),
                 126.549d {+08h 26m 12s} (1950)
GRB_DEC:          -9.027d {-09d 01' 35"} (J2000),
                  -9.084d {-09d 05' 02"} (current),
                  -8.860d {-08d 51' 34"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       12512 [cnts]    Image_Peak=2061 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       23651 [cnts]
BKG_TIME:        81205.41 SOD {22:33:25.41} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        81218.91 SOD {22:33:38.91} UT
GRB_PHI:         -88.66 [deg]
GRB_THETA:         5.20 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     162.10 [sigma]
IMAGE_SIGNIF:    24.42 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +8  +0  +0 +87  +0 
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 51"}
SUN_DIST:        151.74 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.83d {+07h 39m 18s}  +18.15d {+18d 08' 51"}
MOON_DIST:        29.91 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      132.12,-27.20 [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 = 319.86,16.74 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(2.0<100sec) coincident with the FERMI_GBM event (trignum=508286021).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 22:34:05 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      45
TRIGGER_NUM:     508286021
GRB_RA:          126.667d {+08h 26m 40s} (J2000),
                 126.867d {+08h 27m 28s} (current),
                 126.080d {+08h 24m 19s} (1950)
GRB_DEC:         -13.633d {-13d 37' 59"} (J2000),
                 -13.690d {-13d 41' 24"} (current),
                 -13.468d {-13d 28' 04"} (1950)
GRB_ERROR:       19.47 [deg radius, statistical plus systematic]
GRB_INTEN:       215 [cnts/sec]
DATA_SIGNIF:     10.10 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        81216.53 SOD {22:33:36.53} UT
GRB_PHI:         209.00 [deg]
GRB_THETA:        50.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.15
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      98%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 51"}
SUN_DIST:        147.54 [deg]   Sun_angle= -10.9 [hr] (East of Sun)
MOON_POSTN:      114.83d {+07h 39m 19s}  +18.15d {+18d 08' 50"}
MOON_DIST:        33.98 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      236.54, 13.98 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      133.04,-31.76 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208940/quicklook/glg_lc_medres34_bn170208940.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 15.27,-10.65 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the SWIFT_BAT event (trignum=737463).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 22:34:14 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     508286021
GRB_RA:          128.620d {+08h 34m 29s} (J2000),
                 128.825d {+08h 35m 18s} (current),
                 128.019d {+08h 32m 05s} (1950)
GRB_DEC:         -10.430d {-10d 25' 47"} (J2000),
                 -10.490d {-10d 29' 21"} (current),
                 -10.257d {-10d 15' 26"} (1950)
GRB_ERROR:       4.05 [deg radius, statistical only]
DATA_SIGNIF:     48.40 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        81216.53 SOD {22:33:36.53} UT
GRB_PHI:         205.00 [deg]
GRB_THETA:        52.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 50"}
SUN_DIST:        151.27 [deg]   Sun_angle= -11.1 [hr] (East of Sun)
MOON_POSTN:      114.83d {+07h 39m 19s}  +18.15d {+18d 08' 50"}
MOON_DIST:        31.79 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      234.83, 17.33 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      134.12,-28.15 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208940/quicklook/glg_lc_medres34_bn170208940.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_508286021.fits
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/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the SWIFT_BAT event (trignum=737463).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 22:34:11 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      57
TRIGGER_NUM:     508286021
GRB_RA:          126.700d {+08h 26m 48s} (J2000),
                 126.901d {+08h 27m 36s} (current),
                 126.113d {+08h 24m 27s} (1950)
GRB_DEC:         -13.633d {-13d 37' 59"} (J2000),
                 -13.690d {-13d 41' 24"} (current),
                 -13.468d {-13d 28' 04"} (1950)
GRB_ERROR:       5.97 [deg radius, statistical plus systematic]
GRB_INTEN:       623 [cnts/sec]
DATA_SIGNIF:     38.50 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        81216.53 SOD {22:33:36.53} UT
GRB_PHI:         209.00 [deg]
GRB_THETA:        50.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.69
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 51"}
SUN_DIST:        147.56 [deg]   Sun_angle= -10.9 [hr] (East of Sun)
MOON_POSTN:      114.83d {+07h 39m 19s}  +18.15d {+18d 08' 50"}
MOON_DIST:        33.99 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      236.56, 14.01 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      133.08,-31.75 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208940/quicklook/glg_lc_medres34_bn170208940.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 15.27,-10.65 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the SWIFT_BAT event (trignum=737463).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 22:35:14 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.1447d {+08h 28m 34.72s} (J2000),
                 127.3518d {+08h 29m 24.43s} (current),
                 126.5392d {+08h 26m 09.41s} (1950)
GRB_DEC:          -9.0285d {-09d 01' 42.5"} (J2000),
                  -9.0861d {-09d 05' 10.1"} (current),
                  -8.8616d {-08d 51' 41.6"} (1950)
GRB_ERROR:       4.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       7.16e-09 [erg/cm2/sec]
GRB_SIGNIF:      14.14 [sigma]
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81280.67 SOD {22:34:40.67} UT,   61.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.69 237.21 261.67 243.59
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 50"}
SUN_DIST:        151.73 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.84d {+07h 39m 22s}  +18.15d {+18d 08' 46"}
MOON_DIST:        29.90 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.85 [deg] galactic lon,lat of the burst
ECL_COORDS:      132.11,-27.20 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.61 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:     Wed 08 Feb 17 22:35:24 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.1447d {+08h 28m 34.7s} (J2000),
                 127.3518d {+08h 29m 24.4s} (current),
                 126.5392d {+08h 26m 09.4s} (1950)
GRB_DEC:          -9.0285d {-09d 01' 42.5"} (J2000),
                  -9.0861d {-09d 05' 10.1"} (current),
                  -8.8616d {-08d 51' 41.6"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       200 [cnts]
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81280.67 SOD {22:34:40.67} UT,   61.8 [sec] since BAT Trigger Time
CENTROID_X:      273.96,  raw= 274  [pixels]
CENTROID_Y:      299.11,  raw= 299  [pixels]
ROLL:            213.24 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   1.68
GRB_POS_XRT_Z:   -76.46
IMAGE_URL:       sw00737463000msxps_rw.img
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 50"}
SUN_DIST:        151.73 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.84d {+07h 39m 22s}  +18.15d {+18d 08' 46"}
MOON_DIST:        29.90 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.85 [deg] galactic lon,lat of the burst
ECL_COORDS:      132.11,-27.20 [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:     Wed 08 Feb 17 22:35:32 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.1447d {+08h 28m 34.7s} (J2000),
                 127.3518d {+08h 29m 24.4s} (current),
                 126.5392d {+08h 26m 09.4s} (1950)
GRB_DEC:          -9.0285d {-09d 01' 42.5"} (J2000),
                  -9.0861d {-09d 05' 10.1"} (current),
                  -8.8616d {-08d 51' 41.6"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       200 [cnts]
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81280.67 SOD {22:34:40.67} UT,   61.8 [sec] since BAT Trigger Time
CENTROID_X:      273.96,  raw= 274  [pixels]
CENTROID_Y:      299.11,  raw= 299  [pixels]
ROLL:            213.24 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   1.68
GRB_POS_XRT_Z:   -76.46
IMAGE_URL:       sw00737463000msxps_rw.img
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 49"}
SUN_DIST:        151.73 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.84d {+07h 39m 22s}  +18.15d {+18d 08' 45"}
MOON_DIST:        29.90 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.85 [deg] galactic lon,lat of the burst
ECL_COORDS:      132.11,-27.20 [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:     Wed 08 Feb 17 22:37:36 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.155d {+08h 28m 37s} (J2000),
                 127.362d {+08h 29m 27s} (current),
                 126.549d {+08h 26m 12s} (1950)
GRB_DEC:          -9.027d {-09d 01' 35"} (J2000),
                  -9.084d {-09d 05' 02"} (current),
                  -8.860d {-08d 51' 34"} (1950)
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        81218.91 SOD {22:33:38.91} UT
TRIGGER_INDEX:   146
GRB_PHI:         -88.66 [deg]
GRB_THETA:         5.20 [deg]
DELTA_TIME:      -70.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     162.10 [sigma]
IMAGE_SIGNIF:    24.42 [sigma]
LC_URL:          sw00737463000msb.lc
SUN_POSTN:       322.77d {+21h 31m 04s}  -14.70d {-14d 41' 48"}
SUN_DIST:        151.74 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.86d {+07h 39m 28s}  +18.14d {+18d 08' 38"}
MOON_DIST:        29.89 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      132.12,-27.20 [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 = 319.86,16.74 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 22:43:17 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.156d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
POINT_ROLL:      213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81345.86 SOD {22:35:45.86} UT,   126.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.303
N_STARS:         190
X_OFFSET:        0 [pixels]
Y_OFFSET:        0 [pixels]
X_MAX:           2047 [pixels]
Y_MAX:           2047 [pixels]
DET_THRESH:      5
PHOTO_THRESH:    2
SL_URL:          sw00737463000msufc0126.fits
SUN_POSTN:       322.77d {+21h 31m 05s}  -14.70d {-14d 41' 43"}
SUN_DIST:        151.75 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.92d {+07h 39m 42s}  +18.14d {+18d 08' 19"}
MOON_DIST:        29.85 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 22:43:41 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.156d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
POINT_ROLL:      213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81345.86 SOD {22:35:45.86} UT,   126.9 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.303
N_STARS:         190
X_OFFSET:        0 [pixels]
Y_OFFSET:        0 [pixels]
X_MAX:           2047 [pixels]
Y_MAX:           2047 [pixels]
DET_THRESH:      5
PHOTO_THRESH:    2
SL_URL:          sw00737463000msufc0126.fits
SUN_POSTN:       322.77d {+21h 31m 05s}  -14.70d {-14d 41' 43"}
SUN_DIST:        151.75 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.93d {+07h 39m 43s}  +18.14d {+18d 08' 17"}
MOON_DIST:        29.85 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [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:     Wed 08 Feb 17 22:44:39 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.156d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
ROLL:            213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81345.86 SOD {22:35:45.86} UT,   126.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     508286164
X_OFFSET:        933 [pixels]
Y_OFFSET:        796 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1093
Y_GRB_POS:       956
BINNING_INDEX:   1
IM_URL:          sw00737463000msuni0145.fits
SUN_POSTN:       322.77d {+21h 31m 06s}  -14.70d {-14d 41' 42"}
SUN_DIST:        151.75 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.94d {+07h 39m 45s}  +18.14d {+18d 08' 14"}
MOON_DIST:        29.84 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [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:     Wed 08 Feb 17 22:45:04 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.156d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
ROLL:            213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81345.86 SOD {22:35:45.86} UT,   126.9 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     508286164
X_OFFSET:        933 [pixels]
Y_OFFSET:        796 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1093
Y_GRB_POS:       956
BINNING_INDEX:   1
IM_URL:          sw00737463000msuni0145.fits
SUN_POSTN:       322.77d {+21h 31m 06s}  -14.70d {-14d 41' 42"}
SUN_DIST:        151.75 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      114.94d {+07h 39m 46s}  +18.14d {+18d 08' 13"}
MOON_DIST:        29.84 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [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 #20632
M. H. Siegel (PSU), S. D. Barthelmy (GSFC), A. Cholden-Brown (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:
At 22:33:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170208B (trigger=737463). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 127.155, -9.027 which is
```
   RA(J2000)  =  08h 28m 37s
   Dec(J2000) = -09d 01' 35"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows several overlapping peaks with a total duration of about 40 sec. The peak count rate was ~14,500 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 22:34:40.6 UT, 61.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 127.14389, -9.02979 which is equivalent to:
```
   RA(J2000)  = 08h 28m 34.53s
   Dec(J2000) = -09d 01' 47.2"
```
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 40 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 in excess of the Galactic value (5.32 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.9 (+2.27/-2.01) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 7.16e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 250 seconds with the U filter starting 126 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 0.05.
Burst Advocate for this burst is M. H. Siegel (siegel 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:     Wed 08 Feb 17 23:00:48 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.1439d {+08h 28m 34.53s} (J2000),
                 127.3510d {+08h 29m 24.24s} (current),
                 126.5385d {+08h 26m 09.22s} (1950)
GRB_DEC:          -9.0297d {-09d 01' 46.9"} (J2000),
                  -9.0873d {-09d 05' 14.4"} (current),
                  -8.8628d {-08d 51' 45.9"} (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:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81549.00 SOD {22:39:09.00} UT,   330.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       322.78d {+21h 31m 08s}  -14.69d {-14d 41' 29"}
SUN_DIST:        151.72 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      115.10d {+07h 40m 25s}  +18.12d {+18d 07' 19"}
MOON_DIST:        29.77 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.85 [deg] galactic lon,lat of the burst
ECL_COORDS:      132.11,-27.20 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 23:08:30 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.157d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
POINT_ROLL:      213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  82099.88 SOD {22:48:19.88} UT,   881.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.379
N_STARS:         162
X_OFFSET:        373 [pixels]
Y_OFFSET:        236 [pixels]
X_MAX:           1812 [pixels]
Y_MAX:           1675 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00737463000msufc0880.fits
SUN_POSTN:       322.79d {+21h 31m 10s}  -14.69d {-14d 41' 23"}
SUN_DIST:        151.74 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      115.18d {+07h 40m 44s}  +18.11d {+18d 06' 52"}
MOON_DIST:        29.72 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 23:09:09 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     737463,   Seg_Num: 0
GRB_RA:          127.1437d {+08h 28m 34.48s} (J2000),
                 127.3508d {+08h 29m 24.19s} (current),
                 126.5383d {+08h 26m 09.18s} (1950)
GRB_DEC:          -9.0300d {-09d 01' 47.9"} (J2000),
                  -9.0876d {-09d 05' 15.5"} (current),
                  -8.8631d {-08d 51' 47.0"} (1950)
GRB_ERROR:       2.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  81549.00 SOD {22:39:09.00} UT,   330.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       322.79d {+21h 31m 10s}  -14.69d {-14d 41' 22"}
SUN_DIST:        151.72 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      115.19d {+07h 40m 45s}  +18.11d {+18d 06' 50"}
MOON_DIST:        29.73 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.78, 16.85 [deg] galactic lon,lat of the burst
ECL_COORDS:      132.11,-27.20 [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 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 23:08:41 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.157d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
POINT_ROLL:      213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  82099.88 SOD {22:48:19.88} UT,   881.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.379
N_STARS:         162
X_OFFSET:        373 [pixels]
Y_OFFSET:        236 [pixels]
X_MAX:           1812 [pixels]
Y_MAX:           1675 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00737463000msufc0880.fits
SUN_POSTN:       322.79d {+21h 31m 10s}  -14.69d {-14d 41' 23"}
SUN_DIST:        151.74 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      115.18d {+07h 40m 44s}  +18.11d {+18d 06' 51"}
MOON_DIST:        29.72 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [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:     Wed 08 Feb 17 23:09:44 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.157d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
ROLL:            213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  82099.88 SOD {22:48:19.88} UT,   881.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     508286918
X_OFFSET:        932 [pixels]
Y_OFFSET:        795 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1092
Y_GRB_POS:       955
BINNING_INDEX:   1
IM_URL:          sw00737463000msuni0899.fits
SUN_POSTN:       322.79d {+21h 31m 10s}  -14.69d {-14d 41' 22"}
SUN_DIST:        151.74 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      115.20d {+07h 40m 47s}  +18.11d {+18d 06' 48"}
MOON_DIST:        29.72 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [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:     Wed 08 Feb 17 23:10:02 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     737463,   Seg_Num: 0
POINT_RA:        127.157d {+08h 28m 38s} (J2000)
POINT_DEC:        -9.010d {-09d 00' 35"} (J2000)
ROLL:            213.236d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  82099.88 SOD {22:48:19.88} UT,   881.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     508286918
X_OFFSET:        932 [pixels]
Y_OFFSET:        795 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1092
Y_GRB_POS:       955
BINNING_INDEX:   1
IM_URL:          sw00737463000msuni0899.fits
SUN_POSTN:       322.79d {+21h 31m 10s}  -14.69d {-14d 41' 22"}
SUN_DIST:        151.74 [deg]   Sun_angle= -11.0 [hr] (East of Sun)
MOON_POSTN:      115.20d {+07h 40m 48s}  +18.11d {+18d 06' 47"}
MOON_DIST:        29.72 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      232.77, 16.87 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      132.11,-27.18 [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 #20635
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1870 s of XRT Photon Counting mode data and 2 UVOT images for GRB 170208B, 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 = 127.14385, -9.03002 which is equivalent to:
```
RA (J2000): 08h 28m 34.52s
Dec (J2000): -09d 01' 48.1"
```
with an uncertainty of 2.2 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 #20636
B. Gendre (UVI), N. Orange (OrangeWave Innovative Science, LLC), D. Morris (UVI), A. Cucchiara (UVI), D. Drost (UVI), T. Giblin (USAF Academy), J. Hakkila (College of Charleston), A. Klotz (IRAP), J. Neff (NSF), D. Smith (UVI), J. Staff (UVI), P. Thierry (Auragne Observatory), R. Watlington (UVI), and L. Wentlent (UVI) report:
We observed the field of GRB 170208B (Siegel et al., GCN 20632) with the 0.5m Virgin Island Robotic Telescope (VIRT) on February the 9th, starting at 3:10 UT (4.7 hours after the trigger). We performed a series of exposures in the clear filter. The weather conditions were good during the first hour of observation.
We co-added the exposures taken between 3h10UT and 4h17UT. At the position of the X-ray afterglow reported by Goad et al. (GCN 20635), we do not detect any optical emission, with an upper limit of R ~ 19 (estimated from nearby USNO-B1 stars).
Magnitudes have not been corrected for Galactic extinction. The VIRT is still in its commissioning phase.
This message can be cited.
GCN Circular #20637
J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU) and M.H. Siegel report on behalf of the Swift-XRT team:
We have analysed 6.4 ks of XRT data for GRB 170208B (Siegel et al. GCN Circ. 20632), from 50 s to 24.0 ks after the BAT trigger. The data comprise 260 s in Windowed Timing (WT) mode (the first 9 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 Goad et al. (GCN Circ. 20635).
The late-time light curve (from T0+5.4 ks) can be modelled with a power-law decay with a decay index of alpha=0.81 (+0.19, -0.20).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.46 (+/-0.05). The best-fitting absorption column is 4.34 (+/-0.21) x 10^21 cm^-2, in excess of the Galactic value of 5.3 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.07 (+0.15, -0.14) and a best-fitting absorption column of 3.7 (+0.7, -0.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (5.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     3.7 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 5.3 x 10^20 cm^-2
Excess significance: 8.5 sigma
Photon index:	     2.07 (+0.15, -0.14)
```
If the light curve continues to decay with a power-law decay index of 0.81, the count rate at T+24 hours will be 0.020 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.6 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00737463.
This circular is an official product of the Swift-XRT team.
GCN Circular #20638
K. E. Heintz (Univ. Iceland and DARK/NBI), D. Malesani (DARK/NBI and DTU Space), N. R. Tanvir (Univ. Leicester), A. de Ugarte Postigo (IAA-CSIC and DARK/NBI), A. J. Korn (Uppsala Univ.) and I. R. Losada (NOT, NORDITA, and Stockholm Univ.) report on behalf of a larger collaboration:
We observed the field of GRB 170208B (Siegel et al., GCN 20632) using the ALFOSC instrument equipped at the 2.56-m Nordic Optical Telescope (NOT). Observations started at 23:24:13.1 UT on 2017-02-08 (i.e., 50.5 min after the trigger). We obtained SDSS r- and z-band images with 3x300 s and 4x200 s exposures, respectively. The weather conditions were good with a measured seeing of 1.6 and 1.3 arcsec in the r- and z-band, respectively.
In the stacked r- and z-bands no optical afterglow of the burst is detected within the XRT error circle (Goad et al., 20635) at limiting magnitudes of m(r) < 22.5 and m(z) < 22.2 (all AB) mag, calibrated with nearby stars from the Pan-STARRS survey.
GCN Circular #20640
T. Kruehler (MPE Garching) reports:
I observed the field of GRB 170208B (Swift trigger 737463; Siegel et al. GCN 20632) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla Observatory (Chile).
Observations started at 01:22 UT on 2017-02-09, 2.8 hr after the GRB trigger and reveal a faint optical source centered at:
```
RA (J2000): 08:28:34.55
Dec (J2000): -09:01:38.1
```
which is 2.0" away from the center of the XRT error circle (Goad et al. GCN 20635, current 90% error radius of 1.6").
Based on combined images with 66 min of total exposures in g'r'i'z' and 60.0 min in JHK at a mid-time of 02:39 UT on 2017-02-09, this source has the following preliminary magnitudes and upper limits (all in the AB system):
```
g' = 24.5 +- 0.4 mag
r' = 24.4 +- 0.3 mag
i' = 23.4 +- 0.2 mag
z' = 23.1 +- 0.2 mag
J > 21.3 mag
H > 21.0 mag
K > 19.0 mag
```
Given magnitudes are calibrated against Pan-STARRS and 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.042 mag in the direction of the burst (Schlafly & Finkbeiner 2011).
This source is marginally detected already in the archival Pan-STARRS imaging of the field, so it is not the GRB 170208B afterglow. It is, however, a possible host galaxy candidate (the chance coincidence probability of finding a similarly bright object at 2" from the XRT position is around 6%).
I acknowledge excellent help in obtaining these data from the supporting astronomers on La Silla, Sam Kim and Simon Steinmassl.
GCN Circular #20643
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline on behalf of the Konus-Wind team, report:
The long-duration GRB 170208B (Swift-BAT detection: Siegel et al., GCN Circ. 20632) triggered Konus-Wind at T0=81222.750 s UT (22:33:42.750).
The burst light curve shows a single emission episode started at ~T0-5 s with a total duration of ~11 s. The emission is seen up to ~1 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170208_T81222/
As observed by Konus-Wind, the burst had a fluence of 8.17(-0.44,+0.46)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+1.072 s, of 2.55(-0.82,+0.82)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 1 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.78(-0.23,+0.25) and Ep = 105(-7,+8) keV (chi2 = 40/51 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -3.0 (chi2 = 39/50 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #20646
O.J. Roberts (USRA/NASA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 22:33:36.53 UT on the 8th of February 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170208B (trigger 508286021 / 170208940), which was also detected by Konus-Wind (Svinkin et al. 2017, GCN 20643) and Swift (Siegel et al. 2017, GCN 20632). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time using the Swift-XRT position is 54 degrees.
The GBM light curve consists of a long GRB with overlapping episodes of bright emission over a duration (T90) of about 22 s (50-300 keV). The time-averaged spectrum from T0-8.0 s to T0+14.0 s is adequately fit by a Band function with Epeak = 104.1 +/- 5.5 keV, alpha = -0.83 +/- 0.05, and beta = -2.33 +/- 0.09
The event fluence (10-1000 keV) in this time interval is (1.13 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0-7.9 s in the 10-1000 keV band is 12.1 +/- 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 #20647
K. Wiersema, N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), R. Karjalainen, F. Riddick (ING) report on behalf of a larger collaboration:
We observed the field of Swift GRB 170208B (Siegel et al. GCN 20632) with the 4.2m William Herschel Telescope on La Palma. Images were obtained in the Y,J,H,K filters with LIRIS.
In the K-band exposure, for which the mid-time was 2.54 hr post-burst, we find a source with magnitude K(AB)=21.1+/-0.1 within the revised X-ray error circle (Goad et al. GCN 20635).
The source is absent (or very marginally present) in the other infrared filters, which were observed somewhat earlier, to AB mag limits of about 22.5 in each band.
The position of this source is:
```
RA(2000)=08:28:34.55
dec(2000)=-9:01:47.8
```
This is about 1.8 arcsec south of the steady optical source seen by GROND and Pan-STARRS (Kruehler GCN 20640; we note there was a typo in the declination coordinate reported in GCN 20640, Kruehler priv. comm.).
We suggest that the K-band source is most likely the afterglow of the GRB, and is not seen in bluer filters due to dust extinction, while the optical source may be the host galaxy.
GCN Circular #20651
T. Kruehler (MPE Garching) reports: The declination of the source mentioned in my original GCN 20640 contained an error. The correct position is:
```
  
RA (J2000): 08:28:34.55
Dec (J2000): -09:01:46.1
```
I thank N. R. Tanvir for pointing out the error.
GCN Circular #20654
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. H. Siegel (PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170208B (trigger #737463) (Siegel et al., GCN Circ. 20632). The BAT ground-calculated position is RA, Dec = 127.145, -9.027 deg which is
```
   RA(J2000)  =  08h 28m 34.7s
   Dec(J2000) = -09d 01' 36.1"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted light curve shows a bright pulse structure with several overlapping peaks that starts at ~T-5 s and ends at ~T+15 s, followed by a weaker pulse from ~T+100 s to ~T+160 s. There are also some weak emissions that start at ~T-20 s, prior to the first bright pulse. The short spike with duration of ~ 4 ms seen in 15-25 keV at ~T+191.3 s is due to instrumental noise. T90 (15-350 keV) is 128.07 +- 5.75 sec (estimated error including systematics).
The time-averaged spectrum from T-18.20 to T+159.30 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.18 +- 0.21, and Epeak of 97.8 +- 27.4 keV (chi squared 57.4 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 6.1 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+0.42 sec in the 15-150 keV band is 8.4 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.62 +- 0.05 (chi squared 71.7 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/737463/BA/
GCN Circular #20655
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
We observed the field of GRB 170208B (Siegel, et al., GCN 20632) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2017/02 9.11 to 2017/02 9.47 UTC (3.98 to 12.65 hours after the BAT trigger), obtaining a total of 6.02 hours exposure in the r and i bands and 2.52 hours exposure in the Z and Y bands.
We do not detect either the GROND (Kruehler, et al., GCN 20640) source or the WHT (Wiersema, et al., GCN 20647) source. In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma):
```
r > 23.56
i > 23.43
Z > 22.64
Y > 22.55
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The lack of detection of the WHT source is consistent with this source being reddened due to dust or due to a high-z origin if the GROND source is not the GRB host galaxy. The first possibility is also suggested by the significant X-ray column density relative to the Galactic value (Kennea, et al., GCN 20637).
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #20657
M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170208B 127 s after the BAT trigger (Siegel et al., GCN Circ. 20632). No optical afterglow consistent with the enhanced XRT position (Goad et al. GCN Circ. 20635) or the GROND position (Kruehler et al., GCN Circ. 20640) 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

u_FC               127          377          246         >20.7
v                  432         2146          214         >19.6
b                  382         2096          233         >20.3
u                  127         2211          598         >21.3
w1                 482         2195          214         >20.1
m2                 457         2171          214         >19.9
w2                 408         2122          234         >19.7
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #20673
K. L. Murata (Nagoya U), L. Townsend (UCT), I. Monageng (SAAO), Y. Moritani (Kavli IPMU), M. Jian (U of Tokyo), S. Chimasu (Tokai U), A. Kawachi (Tokai U), A. Okazaki (Hokkai-Gakuen U) and T. Nagayama (Kagoshima U)
We observed the field of GRB 170208B (Siegel et al., GCN Circular #20632) with the near-infrared (J, H, Ks) simultaneous imaging camera SIRIUS attached to 1.4 m telescope IRSF (InfraRed Survey Facility) in Sutherland observatory, South Africa.
The observations started on 2017-02-08 22:49:41 UT (~ 15 min. after the burst). We could not detect the afterglow within the enhanced XRT error circle (Goad et al., GCN Circular #20635) in the three bands. We have obtained the following preliminary upper limits (Vega magnitude system):
```
 J > 16.83
 H > 16.31
 Ks > 16.30
```
Given magnitudes were calibrated against 2MASS point sources in this field. The upper limits were determined as the magnitudes of the faintest star within 1 arcmin from the enhanced XRT position.
This observation was carried out by IRSF and OISTER collaboration.
GCN Circular #20674
B. E. Cobb (GWU) reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 170208B (GCN 20632, Siegel et al.) with a mid-exposure time of about 5.1 hours post-burst (2017-02-09 03:38 UT). Total summed exposure times amounted to 36 minutes in I and 30 minutes in J.
No source is detected at the position of the X-ray afterglow (GCN 20635, Goad et al.) to approximate limiting magnitudes of I > 20.9 and J > 19.4. Magnitudes are calibrated using Landolt standard stars in I and 2MASS stars in J.

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Jochen Greiner, last update: 14-Feb-2017 [Disclaimer]