Gamma-ray Burst 170810A

(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:     Thu 10 Aug 17 22:02:00 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     767284,   Seg_Num: 0 
GRB_RA:          187.950d {+12h 31m 48s} (J2000),
                 188.175d {+12h 32m 42s} (current),
                 187.312d {+12h 29m 15s} (1950)
GRB_DEC:          +3.647d {+03d 38' 48"} (J2000),
                  +3.550d {+03d 32' 59"} (current),
                  +3.923d {+03d 55' 21"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4323 [cnts]    Image_Peak=240 [image_cnts]  
TRIGGER_DUR:     1.024 [sec]   
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       23203 [cnts]  
BKG_TIME:        79284.49 SOD {22:01:24.49} UT
BKG_DUR:         8 [sec]       
GRB_DATE:        17975 TJD;   222 DOY;   17/08/10
GRB_TIME:        79301.06 SOD {22:01:41.06} UT
GRB_PHI:         -166.76 [deg] 
GRB_THETA:        24.36 [deg]  
SOLN_STATUS:     0x20010103    
RATE_SIGNIF:     23.32 [sigma]
IMAGE_SIGNIF:    9.65 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +0 -67  +0
SUN_POSTN:       140.89d {+09h 23m 33s}  +15.29d {+15d 17' 40"} 
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.46d {+23h 49m 51s}   -4.10d {-04d 06' 07"}
MOON_DIST:       169.30 [deg]  
MOON_ILLUM:      90 [%]
GAL_COORDS:      290.79, 66.05 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      185.85,  6.50 [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 position matches one of the nearby galaxy sources in the on-board catalog!
COMMENTS:        This does not match any source in the on-board catalog.
COMMENTS:        This matches a source in the ground catalog: NGC4496A, delta=0.295 [deg].
COMMENTS:        This is a GRB in nearby galaxy or it is noise.
COMMENTS:        This trigger occurred at longitude,latitude = 245.74,18.68 [deg].
COMMENTS:
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=524095306).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:02:07 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      45
TRIGGER_NUM:     524095306
GRB_RA:          192.067d {+12h 48m 16s} (J2000),
                 192.292d {+12h 49m 10s} (current),
                 191.427d {+12h 45m 42s} (1950)
GRB_DEC:          +0.450d {+00d 27' 00"} (J2000),
                  +0.354d {+00d 21' 15"} (current),
                  +0.723d {+00d 43' 21"} (1950)
GRB_ERROR:       15.40 [deg radius, statistical plus systematic]
GRB_INTEN:       125 [cnts/sec]
DATA_SIGNIF:     7.90 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        17975 TJD;   222 DOY;   17/08/10
GRB_TIME:        79301.58 SOD {22:01:41.58} UT
GRB_PHI:          61.00 [deg]
GRB_THETA:        65.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.42
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       140.89d {+09h 23m 33s}  +15.29d {+15d 17' 40"}
SUN_DIST:         52.89 [deg]   Sun_angle= -3.4 [hr] (East of Sun)
MOON_POSTN:      357.46d {+23h 49m 51s}   -4.10d {-04d 06' 06"}
MOON_DIST:       164.72 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      301.17, 63.31 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      190.92,  5.18 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170810918/quicklook/glg_lc_medres34_bn170810918.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 200.65,17.27 [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=767284).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:02:19 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     524095306
GRB_RA:          165.090d {+11h 00m 22s} (J2000),
                 165.315d {+11h 01m 16s} (current),
                 164.450d {+10h 57m 48s} (1950)
GRB_DEC:          -0.370d {-00d 22' 11"} (J2000),
                  -0.465d {-00d 27' 52"} (current),
                  -0.101d {-00d 06' 04"} (1950)
GRB_ERROR:       13.27 [deg radius, statistical only]
DATA_SIGNIF:     11.00 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        17975 TJD;   222 DOY;   17/08/10
GRB_TIME:        79301.58 SOD {22:01:41.58} UT
GRB_PHI:          31.00 [deg]
GRB_THETA:        62.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       140.89d {+09h 23m 33s}  +15.29d {+15d 17' 40"}
SUN_DIST:         28.83 [deg]   Sun_angle= -1.6 [hr] (East of Sun)
MOON_POSTN:      357.47d {+23h 49m 52s}   -4.10d {-04d 06' 04"}
MOON_DIST:       167.03 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      254.23, 51.68 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      166.42, -6.22 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170810918/quicklook/glg_lc_medres34_bn170810918.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_524095306.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=767284).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:03:24 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     767284,   Seg_Num: 0
GRB_RA:          187.9396d {+12h 31m 45.50s} (J2000),
                 188.1643d {+12h 32m 39.44s} (current),
                 187.3015d {+12h 29m 12.36s} (1950)
GRB_DEC:          +3.6609d {+03d 39' 39.2"} (J2000),
                  +3.5638d {+03d 33' 49.8"} (current),
                  +3.9368d {+03d 56' 12.6"} (1950)
GRB_ERROR:       4.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       4.45e-09 [erg/cm2/sec]
GRB_SIGNIF:      12.00 [sigma]
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79377.58 SOD {22:02:57.58} UT,   76.5 [sec] since BAT Trigger Time
TAM[0-3]:        327.70 237.21 261.70 243.67
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       140.89d {+09h 23m 34s}  +15.29d {+15d 17' 39"}
SUN_DIST:         47.96 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.48d {+23h 49m 54s}   -4.10d {-04d 05' 52"}
MOON_DIST:       169.32 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      290.75, 66.07 [deg] galactic lon,lat of the burst
ECL_COORDS:      185.84,  6.51 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This matches a source in the BAT ground catalog: NGC4496A,  delta=0.280 [deg].  
COMMENTS:        The XRT position is 1.07 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:03:34 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     767284,   Seg_Num: 0
GRB_RA:          187.9396d {+12h 31m 45.5s} (J2000),
                 188.1643d {+12h 32m 39.4s} (current),
                 187.3015d {+12h 29m 12.3s} (1950)
GRB_DEC:          +3.6609d {+03d 39' 39.2"} (J2000),
                  +3.5638d {+03d 33' 49.8"} (current),
                  +3.9368d {+03d 56' 12.6"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       144 [cnts]
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79377.58 SOD {22:02:57.58} UT,   76.5 [sec] since BAT Trigger Time
CENTROID_X:      259.73,  raw= 260  [pixels]
CENTROID_Y:      291.71,  raw= 292  [pixels]
ROLL:            287.39 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -15.75
GRB_POS_XRT_Z:   -110.00
IMAGE_URL:       sw00767284000msxps_rw.img
SUN_POSTN:       140.89d {+09h 23m 34s}  +15.29d {+15d 17' 39"}
SUN_DIST:         47.96 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.48d {+23h 49m 54s}   -4.10d {-04d 05' 50"}
MOON_DIST:       169.32 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      290.75, 66.07 [deg] galactic lon,lat of the burst
ECL_COORDS:      185.84,  6.51 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:03:36 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     767284,   Seg_Num: 0
GRB_RA:          187.9396d {+12h 31m 45.5s} (J2000),
                 188.1643d {+12h 32m 39.4s} (current),
                 187.3015d {+12h 29m 12.3s} (1950)
GRB_DEC:          +3.6609d {+03d 39' 39.2"} (J2000),
                  +3.5638d {+03d 33' 49.8"} (current),
                  +3.9368d {+03d 56' 12.6"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       144 [cnts]
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79377.58 SOD {22:02:57.58} UT,   76.5 [sec] since BAT Trigger Time
CENTROID_X:      259.73,  raw= 260  [pixels]
CENTROID_Y:      291.71,  raw= 292  [pixels]
ROLL:            287.39 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -15.75
GRB_POS_XRT_Z:   -110.00
IMAGE_URL:       sw00767284000msxps_rw.img
SUN_POSTN:       140.89d {+09h 23m 34s}  +15.29d {+15d 17' 39"}
SUN_DIST:         47.96 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.48d {+23h 49m 54s}   -4.10d {-04d 05' 50"}
MOON_DIST:       169.32 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      290.75, 66.07 [deg] galactic lon,lat of the burst
ECL_COORDS:      185.84,  6.51 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN Circular #21449
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk
D. Buckley, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory
R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB170810A 25 sec after notice time and 45 sec after trigger time at 2017-08-10 22:02:26 UT. On our first (10s exposure) set we found very bright OT.
```
Mag: 11.258
Ra: 187.938775
Dec: 3.660714
```
The message may be cited.
The observations made on zenit distance = 85 degrees, galaxy latitude b = 66 degree. The moon (90 % bright part) is 4 degrees above the horizon. The distance between moon and object is 169 The sun altitude is -27.0 degree. The object can be observed till sunrise at 2017-08-11 06:32:12.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:18:04 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.967d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.648d {+03d 38' 52"} (J2000)
POINT_ROLL:      287.392d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79386.47 SOD {22:03:06.47} UT,   85.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.514
N_STARS:         12
X_OFFSET:        552 [pixels]
Y_OFFSET:        456 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1415 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw00767284000msufc0085.fits
SUN_POSTN:       140.90d {+09h 23m 36s}  +15.29d {+15d 17' 28"}
SUN_DIST:         47.99 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.60d {+23h 50m 25s}   -4.05d {-04d 03' 16"}
MOON_DIST:       169.42 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:18:19 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.967d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.648d {+03d 38' 52"} (J2000)
POINT_ROLL:      287.392d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79386.47 SOD {22:03:06.47} UT,   85.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.514
N_STARS:         12
X_OFFSET:        552 [pixels]
Y_OFFSET:        456 [pixels]
X_MAX:           1511 [pixels]
Y_MAX:           1415 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw00767284000msufc0085.fits
SUN_POSTN:       140.90d {+09h 23m 36s}  +15.29d {+15d 17' 28"}
SUN_DIST:         47.99 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.60d {+23h 50m 25s}   -4.05d {-04d 03' 14"}
MOON_DIST:       169.42 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:24:15 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.967d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.648d {+03d 38' 52"} (J2000)
ROLL:            287.392d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79386.47 SOD {22:03:06.47} UT,   85.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     524095405
X_OFFSET:        1000 [pixels]
Y_OFFSET:        786 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1160
Y_GRB_POS:       946
BINNING_INDEX:   1
IM_URL:          sw00767284000msuni0105.fits
SUN_POSTN:       140.90d {+09h 23m 37s}  +15.29d {+15d 17' 24"}
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.66d {+23h 50m 38s}   -4.04d {-04d 02' 11"}
MOON_DIST:       169.48 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [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:     Thu 10 Aug 17 22:24:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.967d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.648d {+03d 38' 52"} (J2000)
ROLL:            287.392d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79386.47 SOD {22:03:06.47} UT,   85.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     524095405
X_OFFSET:        1000 [pixels]
Y_OFFSET:        786 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1160
Y_GRB_POS:       946
BINNING_INDEX:   1
IM_URL:          sw00767284000msuni0105.fits
SUN_POSTN:       140.90d {+09h 23m 37s}  +15.29d {+15d 17' 24"}
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.66d {+23h 50m 38s}   -4.04d {-04d 02' 09"}
MOON_DIST:       169.48 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:27:49 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.968d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.649d {+03d 38' 58"} (J2000)
POINT_ROLL:      287.390d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  80178.00 SOD {22:16:18.00} UT,   876.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.602
N_STARS:         29
X_OFFSET:        440 [pixels]
Y_OFFSET:        226 [pixels]
X_MAX:           1879 [pixels]
Y_MAX:           1665 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw00767284000msufc0876.fits
SUN_POSTN:       140.91d {+09h 23m 37s}  +15.29d {+15d 17' 21"}
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.69d {+23h 50m 45s}   -4.03d {-04d 01' 33"}
MOON_DIST:       169.51 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:28:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.968d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.649d {+03d 38' 58"} (J2000)
POINT_ROLL:      287.390d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  80178.00 SOD {22:16:18.00} UT,   876.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.602
N_STARS:         29
X_OFFSET:        440 [pixels]
Y_OFFSET:        226 [pixels]
X_MAX:           1879 [pixels]
Y_MAX:           1665 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw00767284000msufc0876.fits
SUN_POSTN:       140.91d {+09h 23m 38s}  +15.29d {+15d 17' 21"}
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.69d {+23h 50m 46s}   -4.03d {-04d 01' 29"}
MOON_DIST:       169.51 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [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:     Thu 10 Aug 17 22:28:29 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.968d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.649d {+03d 38' 58"} (J2000)
ROLL:            287.390d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  80178.00 SOD {22:16:18.00} UT,   876.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     524096197
X_OFFSET:        999 [pixels]
Y_OFFSET:        785 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1159
Y_GRB_POS:       945
BINNING_INDEX:   1
IM_URL:          sw00767284000msuni0896.fits
SUN_POSTN:       140.91d {+09h 23m 38s}  +15.29d {+15d 17' 21"}
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.69d {+23h 50m 46s}   -4.02d {-04d 01' 26"}
MOON_DIST:       169.51 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:28:31 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     767284,   Seg_Num: 0
GRB_RA:          187.9388d {+12h 31m 45.31s} (J2000),
                 188.1635d {+12h 32m 39.25s} (current),
                 187.3007d {+12h 29m 12.17s} (1950)
GRB_DEC:          +3.6602d {+03d 39' 36.7"} (J2000),
                  +3.5631d {+03d 33' 47.2"} (current),
                  +3.9361d {+03d 56' 10.1"} (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:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  79787.00 SOD {22:09:47.00} UT,   485.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       140.91d {+09h 23m 38s}  +15.29d {+15d 17' 21"}
SUN_DIST:         47.95 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.69d {+23h 50m 46s}   -4.02d {-04d 01' 25"}
MOON_DIST:       169.54 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.75, 66.07 [deg] galactic lon,lat of the burst
ECL_COORDS:      185.84,  6.51 [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 2.8% < P(seren) < 6.6%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Aug 17 22:28:15 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     767284,   Seg_Num: 0
POINT_RA:        187.968d {+12h 31m 52s} (J2000)
POINT_DEC:        +3.649d {+03d 38' 58"} (J2000)
ROLL:            287.390d
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  80178.00 SOD {22:16:18.00} UT,   876.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     524096197
X_OFFSET:        999 [pixels]
Y_OFFSET:        785 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1159
Y_GRB_POS:       945
BINNING_INDEX:   1
IM_URL:          sw00767284000msuni0896.fits
SUN_POSTN:       140.91d {+09h 23m 38s}  +15.29d {+15d 17' 21"}
SUN_DIST:         47.98 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.69d {+23h 50m 46s}   -4.02d {-04d 01' 28"}
MOON_DIST:       169.51 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.83, 66.06 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      185.87,  6.51 [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:     Thu 10 Aug 17 22:30:09 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     767284,   Seg_Num: 0
GRB_RA:          187.9388d {+12h 31m 45.31s} (J2000),
                 188.1635d {+12h 32m 39.25s} (current),
                 187.3007d {+12h 29m 12.17s} (1950)
GRB_DEC:          +3.6608d {+03d 39' 38.8"} (J2000),
                  +3.5637d {+03d 33' 49.4"} (current),
                  +3.9367d {+03d 56' 12.2"} (1950)
GRB_ERROR:       1.1 [arcsec radius, statistical only]
GRB_MAG:         17.87 +/- 0.40 [mag]
FILTER:          10, White
IMG_START_DATE:  17975 TJD;   222 DOY;   17/08/10
IMG_START_TIME:  80175.00 SOD {22:16:15.00} UT,   873.9 [sec] since BAT Trigger Time
SUN_POSTN:       140.91d {+09h 23m 38s}  +15.29d {+15d 17' 19"}
SUN_DIST:         47.95 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      357.71d {+23h 50m 50s}   -4.02d {-04d 01' 08"}
MOON_DIST:       169.56 [deg]
MOON_ILLUM:      89 [%]
GAL_COORDS:      290.75, 66.07 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      185.84,  6.51 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The UVOT position is 2.9 arcsec from the XRT position.  
COMMENTS:        Result based on srclist data.  
COMMENTS:        Notice generated automatically.

GCN Circular #21450
S. L. Gibson (U Leicester), D. N. Burrows (PSU), J. A. Kennea (PSU), S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), D. M. Palmer (LANL) and A. Tohuvavohu (PSU) report on behalf of the Swift Team:
At 22:01:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170810A (trigger=767284). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 187.950, +3.647 which is
```
   RA(J2000) = 12h 31m 48s
   Dec(J2000) = +03d 38' 48"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of 160 sec. The peak count rate was ~2600 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 22:02:57.5 UT, 76.5 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 187.9389, 3.6603 which is equivalent to:
```
   RA(J2000)  = 12h 31m 45.33s
   Dec(J2000) = +03d 39' 37.0"
```
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 62 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 (2.23 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.2 (+1.98/-1.79) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 4.45e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 876 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at
```
  RA(J2000)  =	12:31:45.31 = 187.93881
  DEC(J2000) = +03:39:38.9  =	3.66080
```
with a 90%-confidence error radius of about 1.10 arc sec. This position is 3.5 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.87. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03.
An earlier UVOT finding chart exposure, starting 85 seconds after the BAT trigger, showed that the counterpart was much brighter at that time. However, this brightness precluded automatic analysis. Results for this early bright detection will be presented later.
The original GCN notice of this burst suggested an association with the galaxy NGC4496A. However, the apparent separation from this galaxy, 0.295 deg, implies that these two objects are not related.
Burst Advocate for this burst is S. L. Gibson (slg44 AT le.ac.uk). 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 Circular #21451
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1301 s of XRT Photon Counting mode data and 3 UVOT images for GRB 170810A, 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 = 187.93852, +3.66084 which is equivalent to:
```
RA (J2000): 12h 31m 45.24s
Dec (J2000): +03d 39' 39.0"
```
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 #21452
J. L. Racusin (NASA/GSFC), E. Burns (NASA/GSFC), D. Kocevski (NASA/MSFC), F. Longo (University and INFN, Trieste), J. McEnery (NASA/GSFC), S. Razzaque (Johannesburg), G. Vianello (Stanford), report on behalf of the Fermi-LAT team:
Fermi-LAT detected high-energy emission from GRB 170810A, which trigger Fermi-GBM (trigger 524095306 / 170810918) and Swift-BAT (Gibson et al, GCN 21450) at 22:01:41 on August, 10, 2017.
The best LAT on-ground location is found to be
RA, Dec = 187.5, 3.33 (J2000)
with an error radius of 0.53 deg (90 % containment, statistical error only), which is consistent with the Swift BAT, XRT, and UVOT positions (Gibson et al, GCN 21450; Goad et al., GCN 21451), as well as MASTER-NET (Rebolo et al, GCN 21449).
This was 60 deg from the LAT boresight at the time of the trigger.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance.
The highest-energy photon is a 2.3 GeV event which is observed 34 seconds after the GBM trigger.
The Fermi-LAT point of contact for this burst is Judith Racusin (judith.racusin@nasa.gov).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #21453
P Veres and C Meegan (both UAH) report on behalf of the Fermi GBM Team:
"At 22:01:41.58 UT on 10 August 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170810A (trigger 524095306 / 170810918). which was also detected by the Swift/BAT (Gibson et al., GCN 21450) and Fermi LAT (Racusin at al., GCN 21452). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 60 degrees.
The GBM light curve shows multiple pulses with a duration (T90) of about 137 s (50-300 keV). The time-averaged spectrum from T0-6.1 s to T0+67.6 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.79 +/- 0.08 and the cutoff energy, parameterized as Epeak, is 267 +/- 34 keV.
The event fluence (10-1000 keV) in this time interval is (1.0 +/- 0.6)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+38.4 s in the 10-1000 keV band is 2.6 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #21454
GRB 170810A: Swift/UVOT Detection
S. J. LaPorte (PSU) and S. L. Gibson (U. Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170810A 85 s after the BAT trigger (Gibson et al., GCN Circ. 21450). A source consistent with the XRT position (Goad et al. GCN Circ. 21451) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
    RA  (J2000) =  12:31:45.33 = 187.93889 (deg.)
    Dec (J2000) = +03:39:38.9  =   3.66081 (deg.)
```
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               85          235          147         14.64 +/- 0.02
v                  628          648           20         15.88 +/- 0.13
b                  554          574           20         16.62 +/- 0.10
u                  299         1493          281        >19.3
w1                 677         1473           97        >18.9
w2                 604          623           19        >18.0
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #21455
B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU) and S.L. Gibson report on behalf of the Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 170810A (Gibson et al. GCN Circ. 21450), from 66 s to 18.7 ks after the BAT trigger. The data comprise 387 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. 21451).
The late-time light curve (from T0+4.6 ks) can be modelled with a power-law decay with a decay index of alpha=1.33 (+/-0.13).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.60 (+/-0.04). The best-fitting absorption column is 3.5 (+1.0, -0.9) x 10^20 cm^-2, in excess of the Galactic value of 2.2 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.93 (+0.11, -0.10) and a best-fitting absorption column of 5.5 (+2.4, -2.3) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (3.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     5.5 (+2.4, -2.3) x 10^20 cm^-2
Galactic foreground: 2.2 x 10^20 cm^-2
Excess significance: 2.4 sigma
Photon index:	     1.93 (+0.11, -0.10)
```
If the light curve continues to decay with a power-law decay index of 1.33, the count rate at T+24 hours will be 0.012 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.0 x 10^-13 (4.6 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/00767284.
This circular is an official product of the Swift-XRT team.
GCN Circular #21458
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), S. L. Gibson (U Leicester), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), 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+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170810A (trigger #767284) (Gibson, et al., GCN Circ. 21450). The BAT ground-calculated position is RA, Dec = 187.928, 3.664 deg which is
```
    RA(J2000)  =  12h 31m 42.8s
    Dec(J2000) = +03d 39' 49.8"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 93%.
The mask-weighted light curve shows a complex multi-peaked structure that starts at ~T-20 s and ends at ~T+180 s. The brightest peak occurs at ~T+0.5 s. T90 (15-350 keV) is 152.4 +- 21.5 sec (estimated error including systematics).
The time-averaged spectrum from T-24.33 to T+157.74 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.24 +- 0.07. The fluence in the 15-150 keV band is 4.8 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.15 sec in the 15-150 keV band is 1.2 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/767284/BA/
GCN Circular #21471
A. Volnova (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), E. Mazaeva (IKI), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 170810A (Gibson et al., GCN 21450) with AS-32 (0.7m) telescope of Abastumani Observatory starting on August, 11 (UT) 17:02:09. We obtained several unfiltered images of the field. Within enhanced XRT error circle (Goad et al., GCN 21451) we do not detect the afterglow (Rebolo et al, GCN 21449; Gibson et al., GCN 21450). Preliminary photometry of the field is following
```
Date        UT start         t-T0            Filter Exp.   OT   Err UpLim (3 
sigma)
                       (mid, days)                         (s)

2017-08-11 17:02:09  0.80915   CR     33*20  n/d  n/d 18.2
```
Photometry is based on nearby SDSS stars (Lupton transformation)
```
SDSS id                           R_Lupton
J123141.98+033552.6 15.637 0.013
J123153.09+033552.7 14.800 0.012
J123154.00+033945.4 15.540 0.013
```
GCN Circular #21492
K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger (Harvard) report on behalf of a larger collaboration:
We observed the Swift GRB 170810A (Gibson et al., GCN 21450) at multiple frequencies with the Karl G. Jansky Very Large Array (VLA) beginning 2017 August 12.77 UT (1.85 days after the burst). At a mean frequency of 7.1 GHz, we detect a radio source with a preliminary flux density of ~0.1 mJy. In follow-up observations on 2017 August 15.03 UT the source had faded to ~half its original brightness, confirming this as the radio afterglow of GRB 170810A.
The best-fit radio position is
```
RA (J2000) =3D 12:31:45.346
Dec (J2000) =3D +03:39:38.61
```
with an uncertainty of 0.4=E2=80=9D in each coordinate. This is consisten= t with the refined Swift/XRT position (Goad et al. GCN 21451) and the position of th= e Swift/UVOT afterglow (LaPorte et al. GCN 21454).
We thank the VLA staff for rapidly executing these observations.

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Jochen Greiner, last update: 16-Aug-2017 [Disclaimer]