Gamma-ray Burst 160417A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:24:39 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     683076,   Seg_Num: 0
GRB_RA:          120.240d {+08h 00m 58s} (J2000),
                 120.459d {+08h 01m 50s} (current),
                 119.566d {+07h 58m 16s} (1950)
GRB_DEC:          +7.671d {+07d 40' 15"} (J2000),
                  +7.625d {+07d 37' 30"} (current),
                  +7.810d {+07d 48' 35"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       13348 [cnts]    Image_Peak=271 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   452     E_range: 15-50 keV
BKG_INTEN:       116872 [cnts]
BKG_TIME:        15767.86 SOD {04:22:47.86} UT
BKG_DUR:         40 [sec]
GRB_DATE:        17495 TJD;   108 DOY;   16/04/17
GRB_TIME:        15821.04 SOD {04:23:41.04} UT
GRB_PHI:         -170.00 [deg]
GRB_THETA:        45.23 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.20 [sigma]
IMAGE_SIGNIF:    7.19 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +1  -3  +0  +0  +5  +0 
SUN_POSTN:        25.62d {+01h 42m 29s}  +10.62d {+10d 37' 03"}
SUN_DIST:         93.31 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.85d {+10h 15m 24s}   +8.96d {+08d 57' 47"}
MOON_DIST:        33.06 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      120.76,-12.60 [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 = 198.46,-17.76 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:26:21 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.238d {+08h 00m 57s} (J2000)
POINT_DEC:        +7.674d {+07d 40' 27"} (J2000)
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  15953.17 SOD {04:25:53.17} UT,   132.1 [sec] since BAT Trigger Time
COUNTS:          14    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    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:     Sun 17 Apr 16 04:27:27 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     683076,   Seg_Num: 0
GRB_RA:          120.240d {+08h 00m 58s} (J2000),
                 120.459d {+08h 01m 50s} (current),
                 119.566d {+07h 58m 16s} (1950)
GRB_DEC:          +7.671d {+07d 40' 15"} (J2000),
                  +7.625d {+07d 37' 30"} (current),
                  +7.810d {+07d 48' 35"} (1950)
GRB_DATE:        17495 TJD;   108 DOY;   16/04/17
GRB_TIME:        15821.04 SOD {04:23:41.04} UT
TRIGGER_INDEX:   452
GRB_PHI:         -170.00 [deg]
GRB_THETA:        45.23 [deg]
DELTA_TIME:      -38.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.20 [sigma]
IMAGE_SIGNIF:    7.19 [sigma]
LC_URL:          sw00683076000msb.lc
SUN_POSTN:        25.62d {+01h 42m 30s}  +10.62d {+10d 37' 05"}
SUN_DIST:         93.31 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.87d {+10h 15m 30s}   +8.96d {+08d 57' 24"}
MOON_DIST:        33.08 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      120.76,-12.60 [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 = 198.46,-17.76 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:28:51 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.238d {+08h 00m 57s} (J2000)
POINT_DEC:        +7.674d {+07d 40' 27"} (J2000)
POINT_ROLL:      281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  15956.62 SOD {04:25:56.62} UT,   135.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.707
N_STARS:         85
X_OFFSET:        454 [pixels]
Y_OFFSET:        519 [pixels]
X_MAX:           1413 [pixels]
Y_MAX:           1478 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00683076000msufc0135.fits
SUN_POSTN:        25.63d {+01h 42m 30s}  +10.62d {+10d 37' 06"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.89d {+10h 15m 33s}   +8.95d {+08d 57' 12"}
MOON_DIST:        33.10 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.60 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:29:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.238d {+08h 00m 57s} (J2000)
POINT_DEC:        +7.674d {+07d 40' 27"} (J2000)
POINT_ROLL:      281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  15956.62 SOD {04:25:56.62} UT,   135.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.707
N_STARS:         85
X_OFFSET:        454 [pixels]
Y_OFFSET:        519 [pixels]
X_MAX:           1413 [pixels]
Y_MAX:           1478 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00683076000msufc0135.fits
SUN_POSTN:        25.63d {+01h 42m 30s}  +10.62d {+10d 37' 07"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.89d {+10h 15m 34s}   +8.95d {+08d 57' 09"}
MOON_DIST:        33.10 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.60 [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:     Sun 17 Apr 16 04:29:58 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     683076,   Seg_Num: 0
GRB_RA:          120.2579d {+08h 01m 01.89s} (J2000),
                 120.4771d {+08h 01m 54.51s} (current),
                 119.5846d {+07h 58m 20.30s} (1950)
GRB_DEC:          +7.6633d {+07d 39' 47.8"} (J2000),
                  +7.6174d {+07d 37' 02.8"} (current),
                  +7.8022d {+07d 48' 07.8"} (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:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16000.00 SOD {04:26:40.00} UT,   179.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        25.63d {+01h 42m 30s}  +10.62d {+10d 37' 07"}
SUN_DIST:         93.32 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.90d {+10h 15m 35s}   +8.95d {+08d 57' 03"}
MOON_DIST:        33.09 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.93, 18.94 [deg] galactic lon,lat of the burst
ECL_COORDS:      120.78,-12.60 [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 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:30:16 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.238d {+08h 00m 57s} (J2000)
POINT_DEC:        +7.674d {+07d 40' 27"} (J2000)
ROLL:            281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  15956.62 SOD {04:25:56.62} UT,   135.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482559972
X_OFFSET:        773 [pixels]
Y_OFFSET:        838 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       933
Y_GRB_POS:       998
BINNING_INDEX:   1
IM_URL:          sw00683076000msuni0152.fits
SUN_POSTN:        25.63d {+01h 42m 30s}  +10.62d {+10d 37' 08"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.90d {+10h 15m 36s}   +8.95d {+08d 57' 00"}
MOON_DIST:        33.11 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.60 [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:     Sun 17 Apr 16 04:30:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.238d {+08h 00m 57s} (J2000)
POINT_DEC:        +7.674d {+07d 40' 27"} (J2000)
ROLL:            281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  15956.62 SOD {04:25:56.62} UT,   135.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482559972
X_OFFSET:        773 [pixels]
Y_OFFSET:        838 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       933
Y_GRB_POS:       998
BINNING_INDEX:   1
IM_URL:          sw00683076000msuni0152.fits
SUN_POSTN:        25.63d {+01h 42m 30s}  +10.62d {+10d 37' 08"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.90d {+10h 15m 36s}   +8.95d {+08d 56' 58"}
MOON_DIST:        33.11 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.60 [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:     Sun 17 Apr 16 04:32:42 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     683076,   Seg_Num: 0
GRB_RA:          120.2568d {+08h 01m 01.63s} (J2000),
                 120.4760d {+08h 01m 54.25s} (current),
                 119.5835d {+07h 58m 20.04s} (1950)
GRB_DEC:          +7.6628d {+07d 39' 46.0"} (J2000),
                  +7.6169d {+07d 37' 01.0"} (current),
                  +7.8017d {+07d 48' 06.0"} (1950)
GRB_ERROR:       0.6 [arcsec radius, statistical only]
GRB_MAG:         19.14 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  15954.00 SOD {04:25:54.00} UT,   133.0 [sec] since BAT Trigger Time
SUN_POSTN:        25.63d {+01h 42m 31s}  +10.62d {+10d 37' 10"}
SUN_DIST:         93.32 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.92d {+10h 15m 40s}   +8.94d {+08d 56' 40"}
MOON_DIST:        33.11 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.93, 18.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      120.78,-12.60 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN Circular #19316
P. D'Avanzo (INAF-OAB), A. Melandri (INAF-OAB), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 04:23:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160417A (trigger=683076). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 120.240, +7.671 which is
```
   RA(J2000) = 08h 00m 58s
   Dec(J2000) = +07d 40' 15"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex peak structure with a duration of about 30 sec. The peak count rate was ~1100 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 04:25:53.1 UT, 132.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 120.25774, 7.66265 which is equivalent to:
```
   RA(J2000)  = 08h 01m 01.86s
   Dec(J2000) = +07d 39' 45.5"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 70 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.92 x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 135 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	08:01:01.64 = 120.25682
  DEC(J2000) = +07:39:46.4  =	7.66290
```
with a 90%-confidence error radius of about 0.64 arc sec. This position is 4.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 19.15 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02.
Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). 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:     Sun 17 Apr 16 04:36:31 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.677d {+07d 40' 36"} (J2000)
POINT_ROLL:      281.153d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16114.62 SOD {04:28:34.62} UT,   293.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.801
N_STARS:         155
X_OFFSET:        214 [pixels]
Y_OFFSET:        279 [pixels]
X_MAX:           1653 [pixels]
Y_MAX:           1718 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00683076000msufc0293.fits
SUN_POSTN:        25.63d {+01h 42m 31s}  +10.62d {+10d 37' 13"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.95d {+10h 15m 48s}   +8.94d {+08d 56' 08"}
MOON_DIST:        33.16 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:36:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.677d {+07d 40' 36"} (J2000)
POINT_ROLL:      281.153d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16114.62 SOD {04:28:34.62} UT,   293.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.801
N_STARS:         155
X_OFFSET:        214 [pixels]
Y_OFFSET:        279 [pixels]
X_MAX:           1653 [pixels]
Y_MAX:           1718 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    3
SL_URL:          sw00683076000msufc0293.fits
SUN_POSTN:        25.63d {+01h 42m 31s}  +10.62d {+10d 37' 13"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.95d {+10h 15m 48s}   +8.94d {+08d 56' 06"}
MOON_DIST:        33.16 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [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:     Sun 17 Apr 16 04:37:04 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     683076,   Seg_Num: 0
GRB_RA:          120.2567d {+08h 01m 01.60s} (J2000),
                 120.4759d {+08h 01m 54.22s} (current),
                 119.5834d {+07h 58m 20.02s} (1950)
GRB_DEC:          +7.6627d {+07d 39' 45.7"} (J2000),
                  +7.6168d {+07d 37' 00.6"} (current),
                  +7.8016d {+07d 48' 05.6"} (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:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16000.00 SOD {04:26:40.00} UT,   179.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        25.63d {+01h 42m 31s}  +10.62d {+10d 37' 13"}
SUN_DIST:         93.32 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.95d {+10h 15m 49s}   +8.93d {+08d 56' 04"}
MOON_DIST:        33.14 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.93, 18.94 [deg] galactic lon,lat of the burst
ECL_COORDS:      120.78,-12.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:37:46 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.677d {+07d 40' 36"} (J2000)
ROLL:            281.153d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16114.62 SOD {04:28:34.62} UT,   293.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     482560130
X_OFFSET:        773 [pixels]
Y_OFFSET:        838 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       933
Y_GRB_POS:       998
BINNING_INDEX:   1
IM_URL:          sw00683076000msuni0310.fits
SUN_POSTN:        25.63d {+01h 42m 31s}  +10.62d {+10d 37' 14"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.96d {+10h 15m 50s}   +8.93d {+08d 55' 58"}
MOON_DIST:        33.17 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [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:     Sun 17 Apr 16 04:38:04 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.677d {+07d 40' 36"} (J2000)
ROLL:            281.153d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16114.62 SOD {04:28:34.62} UT,   293.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     482560130
X_OFFSET:        773 [pixels]
Y_OFFSET:        838 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       933
Y_GRB_POS:       998
BINNING_INDEX:   1
IM_URL:          sw00683076000msuni0310.fits
SUN_POSTN:        25.63d {+01h 42m 31s}  +10.62d {+10d 37' 14"}
SUN_DIST:         93.30 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      153.96d {+10h 15m 51s}   +8.93d {+08d 55' 56"}
MOON_DIST:        33.17 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [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:     Sun 17 Apr 16 04:43:30 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.676d {+07d 40' 35"} (J2000)
POINT_ROLL:      281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16691.28 SOD {04:38:11.28} UT,   870.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.623
N_STARS:         190
X_OFFSET:        214 [pixels]
Y_OFFSET:        279 [pixels]
X_MAX:           1653 [pixels]
Y_MAX:           1718 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00683076000msufc0870.fits
SUN_POSTN:        25.63d {+01h 42m 32s}  +10.62d {+10d 37' 19"}
SUN_DIST:         93.29 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      154.01d {+10h 16m 02s}   +8.92d {+08d 55' 10"}
MOON_DIST:        33.21 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 17 Apr 16 04:43:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.676d {+07d 40' 35"} (J2000)
POINT_ROLL:      281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16691.28 SOD {04:38:11.28} UT,   870.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.623
N_STARS:         190
X_OFFSET:        214 [pixels]
Y_OFFSET:        279 [pixels]
X_MAX:           1653 [pixels]
Y_MAX:           1718 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00683076000msufc0870.fits
SUN_POSTN:        25.63d {+01h 42m 32s}  +10.62d {+10d 37' 19"}
SUN_DIST:         93.29 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      154.01d {+10h 16m 02s}   +8.92d {+08d 55' 08"}
MOON_DIST:        33.21 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [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:     Sun 17 Apr 16 04:45:04 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.676d {+07d 40' 35"} (J2000)
ROLL:            281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16691.28 SOD {04:38:11.28} UT,   870.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482560707
X_OFFSET:        773 [pixels]
Y_OFFSET:        838 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       933
Y_GRB_POS:       998
BINNING_INDEX:   1
IM_URL:          sw00683076000msuni0887.fits
SUN_POSTN:        25.64d {+01h 42m 33s}  +10.62d {+10d 37' 20"}
SUN_DIST:         93.29 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      154.02d {+10h 16m 05s}   +8.92d {+08d 54' 57"}
MOON_DIST:        33.22 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [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:     Sun 17 Apr 16 04:45:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     683076,   Seg_Num: 0
POINT_RA:        120.240d {+08h 00m 58s} (J2000)
POINT_DEC:        +7.676d {+07d 40' 35"} (J2000)
ROLL:            281.152d
IMG_START_DATE:  17495 TJD;   108 DOY;   16/04/17
IMG_START_TIME:  16691.28 SOD {04:38:11.28} UT,   870.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482560707
X_OFFSET:        773 [pixels]
Y_OFFSET:        838 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       933
Y_GRB_POS:       998
BINNING_INDEX:   1
IM_URL:          sw00683076000msuni0887.fits
SUN_POSTN:        25.64d {+01h 42m 33s}  +10.62d {+10d 37' 21"}
SUN_DIST:         93.29 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:      154.02d {+10h 16m 05s}   +8.92d {+08d 54' 55"}
MOON_DIST:        33.23 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:      213.91, 18.93 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.76,-12.59 [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 #19317
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 160417A (D'Avanzo et al., GCN 19316) about 10 minutes after the trigger. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. Inside the XRT error circle we detected an un-cataloged source with coordinates of :
```
RA =  08:01:01.64 (J2000)
DEC= +07:39:46.60 (J2000)
```
The object location is consistent with the position reported from UVOT (D'Avanzo et al., GCN 19316). The object has clear band mag of ~17.9 about 10 minutes after the burst.
Follow-up observations are encouraged.
GCN Circular #19318
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 1095 s of XRT Photon Counting mode data and 2 UVOT images for GRB 160417A, 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 = 120.25686, +7.66288 which is equivalent to:
```
RA (J2000): 08h 01m 1.65s
Dec (J2000): +07d 39' 46.4"
```
with an uncertainty of 1.8 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 #19319
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of MITSuME and OISTER collaboration:
We observed the field of GRB 160417A (D'Avanzo et al., GCNC 19316) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2016-04-17 11:06:00 UT (~6.7 h after the burst). We could not detect the previously reported afterglow (D'Avanzo et al., GCNC 19316; Zheng et al., GCNC 19317) in all the three bands.
Three sigma upper limits of the OT are listed below. We used SDSS-DR8 catalog for flux calibration.
```
#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc     Ic
-----------------------------------------------------
0.32136    12:06:26    5640.0   >19.7  >19.7  >18.9
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
```
GCN Circular #19320
A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and P. D'Avanzo report on behalf of the Swift-XRT team:
We have analysed 8.0 ks of XRT data for GRB 160417A (D'Avanzo et al. GCN Circ. 19316), from 117 s to 23.2 ks after the BAT trigger. The data comprise 41 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 Osborne et al. (GCN Circ. 19318).
The light curve can be modelled with an initial power-law decay with an index of alpha=4.4 (+0.4, -0.3), followed by a break at T+305 s to an alpha of 0.59 (+/-0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.05 (+0.15, -0.08). The best-fitting absorption column is consistent with the Galactic value of 2.9 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.1 x 10^-11 (3.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.9 (+/-1.9) x 10^20 cm^-2
Galactic foreground: 2.9 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.05 (+0.15, -0.08)
```
If the light curve continues to decay with a power-law decay index of 0.59, the count rate at T+24 hours will be 0.013 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.9 x 10^-13 (4.3 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/00683076.
This circular is an official product of the Swift-XRT team.
GCN Circular #19321
Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill Observatory, Varkaus, Finland) report:
We have detected GRB 160417A optical afterglow at iTelescope observatory T11 (Mayhill, New Mexico) using 0.50-m f/6.8 astrograph and FLI PL11002M CCD. The observations were started at 2016-04-17 05:08:31 (UT). Two unfiltered images with 300 sec exposure time were taken.
The afterglow was detected at the position RA 08:01:01.65 and DEC +07:39:47.6.
The following magnitude was obtained from the observations using USNO-B1.0 0976-0191477 (R2=16.67) as a comparison star:
```
Tmid(s)+T0       Filter         Exp. time         Mag              Mag. Err.
2996                 Clear         2x300s           18.6CR          0.3
```
GCN Circular #19322
A. A. Breeveld (UCL-MSSL) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160417A 136 s after the BAT trigger (D'Avanzo et al., GCN Circ. 19316). The source reported for the UVOT in the initial GCN and also by Zheng=20 and Filippenko (GCN Circ. 19317) is found to be fading.
The preliminary UVOT position is:
```
     RA  (J2000) =3D  08:01:01.64 =3D 120.25685 (deg.)
     Dec (J2000) =3D +07:39:46.4  =3D   7.66289 (deg.)
```
with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT=20 photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for=20 the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              136          285          147         18.92 =B1 0.07
white              870         1020          147         19.14 0.10
v                  623         1070           58         18.54 =B1 0.31
b                  549         1169           58         19.07 =B1 0.21
u                  294          543          246         18.08 =B1 0.08
w1                 672         1280           64        >18.9
m2                 647         1268           78        >19.1
w2                 599         1220           78        >18.8
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) =3D 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #19323
S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), P. D'Avanzo (INAF-OAB), N. Gehrels (GSFC), H. A. Krimm (GSFC/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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160417A (trigger #683076) (D'Avanzo, et al., GCN Circ. 19316). The BAT ground-calculated position is RA, Dec = 120.260, 7.646 deg which is
```
   RA(J2000)  =  08h 01m 02.4s
   Dec(J2000) = +07d 38' 45.6"
```
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 41%.
The mask-weighted light curve shows a multi-peak episode starting ~T-4 sec, and ending around ~T+20 sec. T90 (15-350 keV) is 15 +- 2 sec (estimated error including systematics).
The time-averaged spectrum from T-2.14 to T+13.89 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.93 +- 0.24. The fluence in the 15-150 keV band is 5.9 +- 0.8 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+1.51 sec in the 15-150 keV band is 1.0 +- 0.3 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/683076/BA/
GCN Circular #19324
J.-J. Zhang, J. Mao, and J.-M. Bai (YNAO) report:
We observed the field of GRB 160417A (D'Avanzo et al., GCN 19316) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. Observations began from 12:30:03 UT, Apr. 17th, 2016, about 8.2 hours after the trigger. We obtained the following results at the afterglow position: r~21.1+/- 0.3 mag, i>20.9 mag, and g>21.8 mag.
GCN Circular #19384
V. V. Golovnia (Main Astro Obs., Kyiv) report: We have undertaken the review of the sky area of GRB 160417A (J.P. Osborne et al. GCN Circ. 19318) on astronegatives, collected in Ukrainian plate archive (1976-1996). All the plates with the possible object appearance are digitized using Epson Expression 10000XL flatbed scanner and the images have been placed into Golosiiv Plate Archive database DBGPA with open access to them. The list of plates is given in the table:
```
yyyymmdd/TstartUT- ---Plates--- -Exp. Mag --USNO-A2--
19930202/21:16:48 GUA040C002102 18.9 14.8 0975-05657018
19930216/20:33:08 GUA040C002131 19.5 16.0 0975-05654878
19930312/18:39:20 GUA040C002146 22.5 15.3 0975-05651231

Plates -the plates archive identifier of DWA D/F=400/2000, M=103"/mm
(Marsden's number - 083) the plate number [1].
Exp. - Duration of the maximum exposures (minutes).
Mag - Limited Bmag, derived in the 9 minutes area around the location
given in J.P. Osborne et al.(GCN Circ. 19318):
RA(J2000): 08h 01m 01.64s, Dec(J2000): +07d 39' 46.1".
USNO-A2 - Comparison star.
```
The preview images of 3 areas together with the 9 min. of arc area from Aladin can be found in http://gua.db.ukr-vo.org/img/grb/160417A/index.html. The images with full resolution are available via e-mail on demand.
References:
1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0), http://gua.db.ukr-vo.org.
GCN Circular #19509
K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), C. Rumsey, D. Titterington, S. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)
The AMI Large Array robotically triggered on the Swift alert for GRB 160417A (D'Avanzo et al., GCN 19316) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2016 Apr 17.58, Apr 18.81, Apr 20.66, Apr 24.68, and Apr 28.77 (UT) do not reveal any radio source at the XRT location (Osborne et al., GCN 19318), with 3sigma upper limits of 225 uJy, 105 uJy, 123 uJy, 72 uJy, and 96 uJy respectively.
We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.

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Jochen Greiner, last update: 08-Jun-2016 [Disclaimer]