Gamma-ray Burst 170208A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:11:39 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     737438,   Seg_Num: 0
GRB_RA:          166.563d {+11h 06m 15s} (J2000),
                 166.758d {+11h 07m 02s} (current),
                 165.992d {+11h 03m 58s} (1950)
GRB_DEC:         -46.779d {-46d 46' 43"} (J2000),
                 -46.872d {-46d 52' 17"} (current),
                 -46.509d {-46d 30' 30"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2151 [cnts]    Image_Peak=129 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   127     E_range: 50-350 keV
BKG_INTEN:       17433 [cnts]
BKG_TIME:        65461.41 SOD {18:11:01.41} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        65476.32 SOD {18:11:16.32} UT
GRB_PHI:         -20.11 [deg]
GRB_THETA:        53.24 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     30.00 [sigma]
IMAGE_SIGNIF:    10.10 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +3  +0  +0  +0 +42  +0 
SUN_POSTN:       322.59d {+21h 30m 20s}  -14.76d {-14d 45' 21"}
SUN_DIST:        114.66 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.12d {+07h 28m 29s}  +18.38d {+18d 22' 35"}
MOON_DIST:        81.64 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.84, 12.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      192.19,-47.04 [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 = 115.24,-11.99 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=508270281).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:11:41 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      47
TRIGGER_NUM:     508270281
GRB_RA:          167.167d {+11h 08m 40s} (J2000),
                 167.356d {+11h 09m 25s} (current),
                 166.615d {+11h 06m 28s} (1950)
GRB_DEC:         -54.683d {-54d 40' 59"} (J2000),
                 -54.776d {-54d 46' 33"} (current),
                 -54.412d {-54d 24' 43"} (1950)
GRB_ERROR:       8.47 [deg radius, statistical plus systematic]
GRB_INTEN:       705 [cnts/sec]
DATA_SIGNIF:     21.70 [sigma]
INTEG_TIME:      0.512 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        65476.40 SOD {18:11:16.40} UT
GRB_PHI:         217.00 [deg]
GRB_THETA:       125.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO:      0.62
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       0,0,0, 0,0,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN:       322.59d {+21h 30m 20s}  -14.76d {-14d 45' 21"}
SUN_DIST:        107.36 [deg]   Sun_angle= 10.3 [hr] (West of Sun)
MOON_POSTN:      112.12d {+07h 28m 30s}  +18.38d {+18d 22' 35"}
MOON_DIST:        86.87 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      288.35,  5.25 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      200.14,-53.10 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208758/quicklook/glg_lc_medres34_bn170208758.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 164.43,22.33 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=737438).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:11:55 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     508270281
GRB_RA:          164.700d {+10h 58m 48s} (J2000),
                 164.896d {+10h 59m 35s} (current),
                 164.127d {+10h 56m 31s} (1950)
GRB_DEC:         -42.260d {-42d 15' 35"} (J2000),
                 -42.352d {-42d 21' 06"} (current),
                 -41.992d {-41d 59' 30"} (1950)
GRB_ERROR:       8.74 [deg radius, statistical only]
DATA_SIGNIF:     24.40 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        65476.40 SOD {18:11:16.40} UT
GRB_PHI:         213.00 [deg]
GRB_THETA:       113.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.76d {-14d 45' 20"}
SUN_DIST:        119.31 [deg]   Sun_angle= 10.5 [hr] (West of Sun)
MOON_POSTN:      112.13d {+07h 28m 30s}  +18.38d {+18d 22' 35"}
MOON_DIST:        77.76 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      281.64, 15.91 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      187.05,-44.00 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208758/quicklook/glg_lc_medres34_bn170208758.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_508270281.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
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(0.0<100sec) coincident with the SWIFT_BAT event (trignum=737438).

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Wed 08 Feb 17 18:12:05 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    7685,   Sub_Num: 0
GRB_INTEN:      9.24 [sigma]   
GRB_TIME:       65475.14 SOD {18:11:15.14} UT
GRB_DATE:       17792 TJD;    39 DOY;   17/02/08
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:       Time_Scale=2.0000 and Time_Error=1.0000.
COMMENTS:
COMMENTS:       NOTE: This SPIACS event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=508270281).
COMMENTS:
COMMENTS:       The SPIACS lightcurve can be found at:
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2017-02/2017-02-08T18-11-14.9646-24662-02960-0.lc

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:12:32 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     508270281
GRB_RA:          176.010d {+11h 44m 02s} (J2000),
                 176.223d {+11h 44m 54s} (current),
                 175.388d {+11h 41m 33s} (1950)
GRB_DEC:         -42.210d {-42d 12' 35"} (J2000),
                 -42.305d {-42d 18' 17"} (current),
                 -41.932d {-41d 55' 56"} (1950)
GRB_ERROR:       3.93 [deg radius, statistical only]
DATA_SIGNIF:     23.20 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        65476.40 SOD {18:11:16.40} UT
GRB_PHI:         222.00 [deg]
GRB_THETA:       112.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41531 (Gnd S/W Version number)
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.76d {-14d 45' 20"}
SUN_DIST:        115.09 [deg]   Sun_angle= 9.8 [hr] (West of Sun)
MOON_POSTN:      112.13d {+07h 28m 32s}  +18.38d {+18d 22' 33"}
MOON_DIST:        84.58 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      289.81, 18.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      196.58,-39.56 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208758/quicklook/glg_lc_medres34_bn170208758.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_508270281.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This is likely a Long GRB.  
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(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=7685).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:13:04 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      1
TRIGGER_NUM:     508270281
GRB_RA:          172.780d {+11h 31m 07s} (J2000),
                 172.987d {+11h 31m 57s} (current),
                 172.178d {+11h 28m 43s} (1950)
GRB_DEC:         -46.950d {-46d 57' 00"} (J2000),
                 -47.045d {-47d 02' 39"} (current),
                 -46.674d {-46d 40' 25"} (1950)
GRB_ERROR:       3.67 [deg radius, statistical only]
DATA_SIGNIF:     23.60 [sigma]
DATA_INTERVAL:   7.168 [sec]
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        65476.40 SOD {18:11:16.40} UT
GRB_PHI:         220.00 [deg]
GRB_THETA:       117.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41531 (Gnd S/W Version number)
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.76d {-14d 45' 20"}
SUN_DIST:        112.45 [deg]   Sun_angle= 10.0 [hr] (West of Sun)
MOON_POSTN:      112.14d {+07h 28m 33s}  +18.38d {+18d 22' 31"}
MOON_DIST:        85.16 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      288.97, 13.73 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      197.38,-44.80 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170208758/quicklook/glg_lc_medres34_bn170208758.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_508270281.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This is likely a Long GRB.  
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(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=7685).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:13:51 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.553d {+11h 06m 13s} (J2000)
POINT_DEC:       -46.745d {-46d 44' 42"} (J2000)
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65596.49 SOD {18:13:16.49} UT,   120.2 [sec] since BAT Trigger Time
COUNTS:          17    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        4    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:15:14 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     737438,   Seg_Num: 0
GRB_RA:          166.563d {+11h 06m 15s} (J2000),
                 166.758d {+11h 07m 02s} (current),
                 165.992d {+11h 03m 58s} (1950)
GRB_DEC:         -46.779d {-46d 46' 43"} (J2000),
                 -46.872d {-46d 52' 17"} (current),
                 -46.509d {-46d 30' 30"} (1950)
GRB_DATE:        17792 TJD;    39 DOY;   17/02/08
GRB_TIME:        65476.32 SOD {18:11:16.32} UT
TRIGGER_INDEX:   127
GRB_PHI:         -20.11 [deg]
GRB_THETA:        53.24 [deg]
DELTA_TIME:      -50.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     30.00 [sigma]
IMAGE_SIGNIF:    10.10 [sigma]
LC_URL:          sw00737438000msb.lc
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.76d {-14d 45' 18"}
SUN_DIST:        114.66 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.16d {+07h 28m 38s}  +18.37d {+18d 22' 25"}
MOON_DIST:        81.62 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.84, 12.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      192.19,-47.04 [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 = 115.24,-11.99 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:16:25 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.553d {+11h 06m 13s} (J2000)
POINT_DEC:       -46.745d {-46d 44' 41"} (J2000)
POINT_ROLL:      154.311d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65600.62 SOD {18:13:20.62} UT,   124.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.105
N_STARS:         190
X_OFFSET:        728 [pixels]
Y_OFFSET:        487 [pixels]
X_MAX:           1687 [pixels]
Y_MAX:           1446 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00737438000msufc0124.fits
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.75d {-14d 45' 17"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.17d {+07h 28m 41s}  +18.37d {+18d 22' 22"}
MOON_DIST:        81.58 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:16:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.553d {+11h 06m 13s} (J2000)
POINT_DEC:       -46.745d {-46d 44' 41"} (J2000)
POINT_ROLL:      154.311d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65600.62 SOD {18:13:20.62} UT,   124.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.105
N_STARS:         190
X_OFFSET:        728 [pixels]
Y_OFFSET:        487 [pixels]
X_MAX:           1687 [pixels]
Y_MAX:           1446 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00737438000msufc0124.fits
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.75d {-14d 45' 16"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.18d {+07h 28m 42s}  +18.37d {+18d 22' 20"}
MOON_DIST:        81.58 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:17:37 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.553d {+11h 06m 13s} (J2000)
POINT_DEC:       -46.745d {-46d 44' 41"} (J2000)
ROLL:            154.311d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65600.62 SOD {18:13:20.62} UT,   124.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     508270419
X_OFFSET:        1047 [pixels]
Y_OFFSET:        806 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1207
Y_GRB_POS:       966
BINNING_INDEX:   1
IM_URL:          sw00737438000msuni0143.fits
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.75d {-14d 45' 16"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.18d {+07h 28m 44s}  +18.37d {+18d 22' 18"}
MOON_DIST:        81.58 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Feb 17 18:17:16 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.553d {+11h 06m 13s} (J2000)
POINT_DEC:       -46.745d {-46d 44' 41"} (J2000)
ROLL:            154.311d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65600.62 SOD {18:13:20.62} UT,   124.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     508270419
X_OFFSET:        1047 [pixels]
Y_OFFSET:        806 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1207
Y_GRB_POS:       966
BINNING_INDEX:   1
IM_URL:          sw00737438000msuni0143.fits
SUN_POSTN:       322.59d {+21h 30m 21s}  -14.75d {-14d 45' 16"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.18d {+07h 28m 43s}  +18.37d {+18d 22' 19"}
MOON_DIST:        81.58 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:18:17 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     737438,   Seg_Num: 0
GRB_RA:          166.5639d {+11h 06m 15.33s} (J2000),
                 166.7597d {+11h 07m 02.32s} (current),
                 165.9933d {+11h 03m 58.39s} (1950)
GRB_DEC:         -46.7673d {-46d 46' 02.2"} (J2000),
                 -46.8600d {-46d 51' 35.8"} (current),
                 -46.4968d {-46d 29' 48.6"} (1950)
GRB_ERROR:       3.9 [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:  65658.00 SOD {18:14:18.00} UT,   181.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       322.59d {+21h 30m 22s}  -14.75d {-14d 45' 15"}
SUN_DIST:        114.67 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.19d {+07h 28m 46s}  +18.37d {+18d 22' 16"}
MOON_DIST:        81.59 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.83, 12.37 [deg] galactic lon,lat of the burst
ECL_COORDS:      192.18,-47.03 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
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 18:25:15 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 37"} (J2000)
POINT_ROLL:      154.310d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65813.30 SOD {18:16:53.30} UT,   337.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.680
N_STARS:         190
X_OFFSET:        488 [pixels]
Y_OFFSET:        247 [pixels]
X_MAX:           1927 [pixels]
Y_MAX:           1686 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00737438000msufc0336.fits
SUN_POSTN:       322.59d {+21h 30m 23s}  -14.75d {-14d 45' 10"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.26d {+07h 29m 03s}  +18.37d {+18d 21' 56"}
MOON_DIST:        81.53 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:25:47 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     737438,   Seg_Num: 0
GRB_RA:          166.5641d {+11h 06m 15.38s} (J2000),
                 166.7599d {+11h 07m 02.37s} (current),
                 165.9935d {+11h 03m 58.43s} (1950)
GRB_DEC:         -46.7672d {-46d 46' 01.9"} (J2000),
                 -46.8599d {-46d 51' 35.5"} (current),
                 -46.4967d {-46d 29' 48.2"} (1950)
GRB_ERROR:       2.2 [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:  65658.00 SOD {18:14:18.00} UT,   181.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       322.60d {+21h 30m 23s}  -14.75d {-14d 45' 09"}
SUN_DIST:        114.68 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.27d {+07h 29m 04s}  +18.37d {+18d 21' 54"}
MOON_DIST:        81.55 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.83, 12.38 [deg] galactic lon,lat of the burst
ECL_COORDS:      192.18,-47.03 [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 18:25:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 37"} (J2000)
POINT_ROLL:      154.310d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65813.30 SOD {18:16:53.30} UT,   337.0 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.680
N_STARS:         190
X_OFFSET:        488 [pixels]
Y_OFFSET:        247 [pixels]
X_MAX:           1927 [pixels]
Y_MAX:           1686 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00737438000msufc0336.fits
SUN_POSTN:       322.60d {+21h 30m 23s}  -14.75d {-14d 45' 09"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.27d {+07h 29m 04s}  +18.37d {+18d 21' 55"}
MOON_DIST:        81.52 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:26:29 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 37"} (J2000)
ROLL:            154.310d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65813.30 SOD {18:16:53.30} UT,   337.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     508270631
X_OFFSET:        1047 [pixels]
Y_OFFSET:        806 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1207
Y_GRB_POS:       966
BINNING_INDEX:   1
IM_URL:          sw00737438000msuni0355.fits
SUN_POSTN:       322.60d {+21h 30m 23s}  -14.75d {-14d 45' 09"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.28d {+07h 29m 06s}  +18.36d {+18d 21' 52"}
MOON_DIST:        81.52 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:26:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 37"} (J2000)
ROLL:            154.310d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  65813.30 SOD {18:16:53.30} UT,   337.0 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     508270631
X_OFFSET:        1047 [pixels]
Y_OFFSET:        806 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1207
Y_GRB_POS:       966
BINNING_INDEX:   1
IM_URL:          sw00737438000msuni0355.fits
SUN_POSTN:       322.60d {+21h 30m 23s}  -14.75d {-14d 45' 09"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.28d {+07h 29m 07s}  +18.36d {+18d 21' 51"}
MOON_DIST:        81.52 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 #20631
A. Cholden-Brown (PSU), D. N. Burrows (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 18:11:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170208A (trigger=737438). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 166.563, -46.779 which is
```
   RA(J2000) = 11h 06m 15s
   Dec(J2000) = -46d 46' 43"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 10 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 18:13:16.4 UT, 120.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 166.5643, -46.7674 which is equivalent to:
```
   RA(J2000)  = 11h 06m 15.44s
   Dec(J2000) = -46d 46' 02.6"
```
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 41 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 (1.25 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.4 (+2.01/-1.79) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 124 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 none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.13.
Burst Advocate for this burst is A. Cholden-Brown (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:     Wed 08 Feb 17 18:32:24 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 36"} (J2000)
POINT_ROLL:      154.309d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  66344.70 SOD {18:25:44.70} UT,   868.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.180
N_STARS:         190
X_OFFSET:        488 [pixels]
Y_OFFSET:        247 [pixels]
X_MAX:           1927 [pixels]
Y_MAX:           1686 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00737438000msufc0868.fits
SUN_POSTN:       322.60d {+21h 30m 24s}  -14.75d {-14d 45' 04"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.34d {+07h 29m 21s}  +18.36d {+18d 21' 35"}
MOON_DIST:        81.48 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:32:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 36"} (J2000)
POINT_ROLL:      154.309d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  66344.70 SOD {18:25:44.70} UT,   868.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.180
N_STARS:         190
X_OFFSET:        488 [pixels]
Y_OFFSET:        247 [pixels]
X_MAX:           1927 [pixels]
Y_MAX:           1686 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00737438000msufc0868.fits
SUN_POSTN:       322.60d {+21h 30m 24s}  -14.75d {-14d 45' 04"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.34d {+07h 29m 22s}  +18.36d {+18d 21' 34"}
MOON_DIST:        81.48 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:33:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 36"} (J2000)
ROLL:            154.309d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  66344.70 SOD {18:25:44.70} UT,   868.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     508271163
X_OFFSET:        1047 [pixels]
Y_OFFSET:        806 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1207
Y_GRB_POS:       966
BINNING_INDEX:   1
IM_URL:          sw00737438000msuni0887.fits
SUN_POSTN:       322.60d {+21h 30m 24s}  -14.75d {-14d 45' 03"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.35d {+07h 29m 25s}  +18.36d {+18d 21' 31"}
MOON_DIST:        81.47 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 18:34:22 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     737438,   Seg_Num: 0
POINT_RA:        166.552d {+11h 06m 12s} (J2000)
POINT_DEC:       -46.744d {-46d 44' 36"} (J2000)
ROLL:            154.309d
IMG_START_DATE:  17792 TJD;    39 DOY;   17/02/08
IMG_START_TIME:  66344.70 SOD {18:25:44.70} UT,   868.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     508271163
X_OFFSET:        1047 [pixels]
Y_OFFSET:        806 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1207
Y_GRB_POS:       966
BINNING_INDEX:   1
IM_URL:          sw00737438000msuni0887.fits
SUN_POSTN:       322.60d {+21h 30m 24s}  -14.75d {-14d 45' 03"}
SUN_DIST:        114.70 [deg]   Sun_angle= 10.4 [hr] (West of Sun)
MOON_POSTN:      112.36d {+07h 29m 26s}  +18.36d {+18d 21' 29"}
MOON_DIST:        81.47 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      284.82, 12.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      192.15,-47.02 [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 #20633
O.J. Roberts (USRA/NASA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 18:11:16.40 UT on the 8th of February 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170208A (trigger 508270281 / 170208758), which was also detected by Swift (A. Cholden-Brown et al. 2017, GCN 20631). 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 117 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.
The GBM light curve consists of a long GRB with several episodes of bright emission over a duration (T90) of about 7 s (50-300 keV). The time-averaged spectrum from T0+0 s to T0+7.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.92 +/- 0.09 and the cutoff energy, parameterized as Epeak is 246.9 +/- 30.5 keV
The event fluence (10-1000 keV) in this time interval is (3.10 +/- 0.19)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.13 s in the 10-1000 keV band is 8.1 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #20634
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1316 s of XRT Photon Counting mode data and 2 UVOT images for GRB 170208A, 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 = 166.56468, -46.76827 which is equivalent to:
```
RA (J2000): 11h 06m 15.52s
Dec (J2000): -46d 46' 05.8"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #20641
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 170208A (Swift-BAT detection: Cholden-Brown et al., GCN Circ. 20631; Fermi-GBM detection: Roberts and Meegan, GCN Circ. 20633) triggered Konus-Wind at T0=65479.756 s UT (18:11:19.756).
The burst light curve shows a multipeaked structure started at ~T0-0.4 s with a total duration of ~8 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_T65479/
As observed by Konus-Wind, the burst had a fluence of 2.62(-0.31,+0.37)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0-0.012 s, of 1.94(-0.65,+0.67)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 - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.52(-0.46,+0.56) and Ep = 153(-24,+36) keV (chi2 = 67/60 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.7 (chi2 = 67/59 dof)
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #20644
M. H. Siegel (PSU) and A. Cholden-Brown (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170208A 125 s after the BAT trigger (Cholden-Brown et al., GCN Circ. 20631). No optical afterglow consistent with the enhanced XRT position (Evans et al. GCN Circ. 20634) 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           125          275          148         >21.4
u_FC               337          587          246         >20.7
white              125         1365          373         >21.9
v                  667         1415           97         >19.3
b                  593         1503           87         >19.4
u                  337         1489          324         >20.2
w1                 717         1464           78         >19.4
w2                 642         1390           97         >19.3
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.13 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #20649
B. Sbarufatti (INAF-OAB/PSU), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU) and A. Cholden-Brown report on behalf of the Swift-XRT team:
We have analysed 5.5 ks of XRT data for GRB 170208A (Cholden-Brown et al. GCN Circ. 20631), from 105 s to 13.0 ks after the BAT trigger. The data comprise 56 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. 20634).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.075 (+0.030, -0.029).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.97 (+/-0.17). The best-fitting absorption column is 4.5 (+1.0, -0.9) x 10^21 cm^-2, in excess of the Galactic value of 1.3 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     4.5 (+1.0, -0.9) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: 6.2 sigma
Photon index:	     1.97 (+/-0.17)
```
If the light curve continues to decay with a power-law decay index of 1.075, the count rate at T+24 hours will be 6.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x 10^-13 (4.2 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/00737438.
This circular is an official product of the Swift-XRT team.
GCN Circular #20653
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), A. Cholden-Brown (PSU), J. R. Cummings (CPI), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170208A (trigger #737438) (Cholden-Brown, et al., GCN Circ. 20631). The BAT ground-calculated position is RA, Dec = 166.544, -46.786 deg which is
```
   RA(J2000)  =  11h 06m 10.5s
   Dec(J2000) = -46d 47' 08.8"
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 17%.
The mask-weighted light curve shows a pulse from ~T0 to ~T+1.5 s, followed by some weaker emissions that last till ~T+8 s. T90 (15-350 keV) is 7.45 +- 0.54 sec (estimated error including systematics).
The time-averaged spectrum from T-0.04 to T+8.06 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.04 +- 0.13. The fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.04 sec in the 15-150 keV band is 5.4 +- 0.6 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/737438/BA/
GCN Circular #20671
V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IITB), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed clear detection of GRB 170208A (Swift detection: A. Cholden-Brown et al., GCN Circ. 20631) in the 40-200 keV energy range. The light curve shows multiple peaks structure with maximum counts at 18:11:16.0 UT peak, which coincides with Swift trigger. The measured peak count rate is 316.9 counts/sec above the background in combined data of four quadrants, with a total of 1106.2 counts. The local mean background count rate was 425.1 counts/sec. Using cumulative rates, we measure a T90 of 10.7 secs.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular #20672
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 170208A (Cholden-Brown et al., GCN Circular #20631) 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 18:56:55 UT (~ 43 min. after the burst). We could not detect the afterglow within the enhanced XRT error circle (Evans et al., GCN Circular #20634) in the three bands. We have obtained the following preliminary upper limits (Vega magnitude system):
```
 J > 16.50
 H > 16.25
 Ks > 15.92
```
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.

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