Gamma-ray Burst 160227A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:33:33 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.788d {+12h 59m 09s} (J2000),
                 194.881d {+12h 59m 32s} (current),
                 194.503d {+12h 58m 01s} (1950)
GRB_DEC:         +78.639d {+78d 38' 21"} (J2000),
                 +78.552d {+78d 33' 08"} (current),
                 +78.909d {+78d 54' 31"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1147 [image_cnts]
TRIGGER_DUR:     72.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        17445 TJD;    58 DOY;   16/02/27
GRB_TIME:        70328.09 SOD {19:32:08.09} UT
GRB_PHI:         -82.73 [deg]
GRB_THETA:        27.07 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.02 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -3  +0  +0 +30  +0 
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 43"}
SUN_DIST:        107.67 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.88d {+14h 11m 32s}   -9.42d {-09d 24' 55"}
MOON_DIST:        88.52 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.45, 38.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      118.98, 66.85 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 106.95,-6.74 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:35:14 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.7974d {+12h 59m 11.37s} (J2000),
                 194.8898d {+12h 59m 33.54s} (current),
                 194.5130d {+12h 58m 03.11s} (1950)
GRB_DEC:         +78.6768d {+78d 40' 36.4"} (J2000),
                 +78.5899d {+78d 35' 23.4"} (current),
                 +78.9461d {+78d 56' 46.1"} (1950)
GRB_ERROR:       5.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.67e-09 [erg/cm2/sec]
GRB_SIGNIF:      9.53 [sigma]
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70479.95 SOD {19:34:39.95} UT,   151.9 [sec] since BAT Trigger Time
TAM[0-3]:        327.64 237.24 261.60 243.49
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 41"}
SUN_DIST:        107.64 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.90d {+14h 11m 35s}   -9.42d {-09d 25' 08"}
MOON_DIST:        88.56 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.45, 38.44 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.89, 66.86 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.26 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:35:23 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.7974d {+12h 59m 11.3s} (J2000),
                 194.8898d {+12h 59m 33.5s} (current),
                 194.5130d {+12h 58m 03.1s} (1950)
GRB_DEC:         +78.6768d {+78d 40' 36.4"} (J2000),
                 +78.5899d {+78d 35' 23.4"} (current),
                 +78.9461d {+78d 56' 46.1"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       91 [cnts]
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70479.95 SOD {19:34:39.95} UT,   151.9 [sec] since BAT Trigger Time
CENTROID_X:      219.96,  raw= 220  [pixels]
CENTROID_Y:      314.83,  raw= 315  [pixels]
ROLL:            35.90 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   40.14
GRB_POS_XRT_Z:   -201.16
IMAGE_URL:       sw00676423000msxps_rw.img
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 41"}
SUN_DIST:        107.64 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.90d {+14h 11m 36s}   -9.42d {-09d 25' 09"}
MOON_DIST:        88.56 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.45, 38.44 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.89, 66.86 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:35:31 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.7974d {+12h 59m 11.3s} (J2000),
                 194.8898d {+12h 59m 33.5s} (current),
                 194.5130d {+12h 58m 03.1s} (1950)
GRB_DEC:         +78.6768d {+78d 40' 36.4"} (J2000),
                 +78.5899d {+78d 35' 23.4"} (current),
                 +78.9461d {+78d 56' 46.1"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       91 [cnts]
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70479.95 SOD {19:34:39.95} UT,   151.9 [sec] since BAT Trigger Time
CENTROID_X:      219.96,  raw= 220  [pixels]
CENTROID_Y:      314.83,  raw= 315  [pixels]
ROLL:            35.90 [deg]
GAIN:            2
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   40.14
GRB_POS_XRT_Z:   -201.16
IMAGE_URL:       sw00676423000msxps_rw.img
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 41"}
SUN_DIST:        107.64 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.90d {+14h 11m 36s}   -9.42d {-09d 25' 10"}
MOON_DIST:        88.56 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.45, 38.44 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.89, 66.86 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:36:16 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.788d {+12h 59m 09s} (J2000),
                 194.881d {+12h 59m 32s} (current),
                 194.503d {+12h 58m 01s} (1950)
GRB_DEC:         +78.639d {+78d 38' 21"} (J2000),
                 +78.552d {+78d 33' 08"} (current),
                 +78.909d {+78d 54' 31"} (1950)
GRB_DATE:        17445 TJD;    58 DOY;   16/02/27
GRB_TIME:        70328.09 SOD {19:32:08.09} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -82.73 [deg]
GRB_THETA:        27.07 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     72.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.02 [sigma]
LC_URL:          sw00676423000msb.lc
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 40"}
SUN_DIST:        107.67 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.90d {+14h 11m 37s}   -9.42d {-09d 25' 16"}
MOON_DIST:        88.52 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.45, 38.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      118.98, 66.85 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is an image trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 106.95,-6.74 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:38:00 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.678d {+12h 58m 43s} (J2000)
POINT_DEC:       +78.626d {+78d 37' 33"} (J2000)
POINT_ROLL:      35.903d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70489.41 SOD {19:34:49.41} UT,   161.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.431
N_STARS:         36
X_OFFSET:        680 [pixels]
Y_OFFSET:        520 [pixels]
X_MAX:           1639 [pixels]
Y_MAX:           1479 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00676423000msufc0161.fits
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 39"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.92d {+14h 11m 41s}   -9.43d {-09d 25' 30"}
MOON_DIST:        88.52 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.47, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.00, 66.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:38:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.678d {+12h 58m 43s} (J2000)
POINT_DEC:       +78.626d {+78d 37' 33"} (J2000)
POINT_ROLL:      35.903d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70489.41 SOD {19:34:49.41} UT,   161.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.431
N_STARS:         36
X_OFFSET:        680 [pixels]
Y_OFFSET:        520 [pixels]
X_MAX:           1639 [pixels]
Y_MAX:           1479 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00676423000msufc0161.fits
SUN_POSTN:       340.26d {+22h 41m 03s}   -8.33d {-08d 19' 38"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.92d {+14h 11m 41s}   -9.43d {-09d 25' 33"}
MOON_DIST:        88.52 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.47, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.00, 66.83 [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:     Sat 27 Feb 16 19:39:12 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.678d {+12h 58m 43s} (J2000)
POINT_DEC:       +78.626d {+78d 37' 33"} (J2000)
ROLL:            35.903d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70489.41 SOD {19:34:49.41} UT,   161.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     478294505
X_OFFSET:        1127 [pixels]
Y_OFFSET:        602 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1287
Y_GRB_POS:       762
BINNING_INDEX:   1
IM_URL:          sw00676423000msuni0177.fits
SUN_POSTN:       340.26d {+22h 41m 04s}   -8.33d {-08d 19' 38"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.93d {+14h 11m 43s}   -9.43d {-09d 25' 40"}
MOON_DIST:        88.53 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.47, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.00, 66.83 [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:     Sat 27 Feb 16 19:39:28 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.678d {+12h 58m 43s} (J2000)
POINT_DEC:       +78.626d {+78d 37' 33"} (J2000)
ROLL:            35.903d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70489.41 SOD {19:34:49.41} UT,   161.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     478294505
X_OFFSET:        1127 [pixels]
Y_OFFSET:        602 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1287
Y_GRB_POS:       762
BINNING_INDEX:   1
IM_URL:          sw00676423000msuni0177.fits
SUN_POSTN:       340.26d {+22h 41m 04s}   -8.33d {-08d 19' 37"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.93d {+14h 11m 43s}   -9.43d {-09d 25' 42"}
MOON_DIST:        88.53 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.47, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.00, 66.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:41:46 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.8076d {+12h 59m 13.82s} (J2000),
                 194.8999d {+12h 59m 35.97s} (current),
                 194.5235d {+12h 58m 05.63s} (1950)
GRB_DEC:         +78.6791d {+78d 40' 44.7"} (J2000),
                 +78.5922d {+78d 35' 31.7"} (current),
                 +78.9484d {+78d 56' 54.3"} (1950)
GRB_ERROR:       0.8 [arcsec radius, statistical only]
GRB_MAG:         19.31 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70487.00 SOD {19:34:47.00} UT,   158.9 [sec] since BAT Trigger Time
SUN_POSTN:       340.27d {+22h 41m 04s}   -8.33d {-08d 19' 35"}
SUN_DIST:        107.64 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.95d {+14h 11m 48s}   -9.43d {-09d 26' 00"}
MOON_DIST:        88.58 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.44, 38.44 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      118.88, 66.87 [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 10.8 arcsec from the XRT position.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:43:56 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.670d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
POINT_ROLL:      35.895d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70647.56 SOD {19:37:27.56} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.407
N_STARS:         22
X_OFFSET:        807 [pixels]
Y_OFFSET:        282 [pixels]
X_MAX:           1766 [pixels]
Y_MAX:           1241 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00676423000msufc0319.fits
SUN_POSTN:       340.27d {+22h 41m 04s}   -8.33d {-08d 19' 33"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.97d {+14h 11m 52s}   -9.44d {-09d 26' 17"}
MOON_DIST:        88.54 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:44:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.670d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
POINT_ROLL:      35.895d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70647.56 SOD {19:37:27.56} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.407
N_STARS:         22
X_OFFSET:        807 [pixels]
Y_OFFSET:        282 [pixels]
X_MAX:           1766 [pixels]
Y_MAX:           1241 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00676423000msufc0319.fits
SUN_POSTN:       340.27d {+22h 41m 04s}   -8.33d {-08d 19' 33"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.97d {+14h 11m 53s}   -9.44d {-09d 26' 20"}
MOON_DIST:        88.54 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [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:     Sat 27 Feb 16 19:45:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.670d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
ROLL:            35.895d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70647.56 SOD {19:37:27.56} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     478294663
X_OFFSET:        1127 [pixels]
Y_OFFSET:        602 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1287
Y_GRB_POS:       762
BINNING_INDEX:   1
IM_URL:          sw00676423000msuni0335.fits
SUN_POSTN:       340.27d {+22h 41m 04s}   -8.33d {-08d 19' 32"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.98d {+14h 11m 54s}   -9.44d {-09d 26' 27"}
MOON_DIST:        88.54 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [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:     Sat 27 Feb 16 19:45:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.670d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
ROLL:            35.895d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  70647.56 SOD {19:37:27.56} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     478294663
X_OFFSET:        1127 [pixels]
Y_OFFSET:        602 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1287
Y_GRB_POS:       762
BINNING_INDEX:   1
IM_URL:          sw00676423000msuni0335.fits
SUN_POSTN:       340.27d {+22h 41m 05s}   -8.33d {-08d 19' 32"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      212.98d {+14h 11m 55s}   -9.44d {-09d 26' 29"}
MOON_DIST:        88.54 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #19098
M. H. Siegel (PSU), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), L. M. McCauley (PSU), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and T. N. Ukwatta (LANL) report on behalf of the Swift Team:
At 19:32:08 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160227A (trigger=676423). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 194.788, +78.639 which is
```
   RA(J2000) = 12h 59m 09s
   Dec(J2000) = +78d 38' 21"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a early complex structure followed by a stronger peak at around 100 s after the trigger, for a total duration of at least 160 s. The peak count rate was ~700 counts/sec (15-350 keV), at ~100 sec after the trigger.
The XRT began observing the field at 19:34:39.9 UT, 151.8 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 194.7974, 78.6768 which is equivalent to:
```
   RA(J2000)  = +12h 59m 11.38s
   Dec(J2000) = +78d 40' 36.5"
```
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 136 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 2.67e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 161 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	12:59:13.84 = 194.80767
  DEC(J2000) = +78:40:44.9  =  78.67913
```
with a 90%-confidence error radius of about 0.77 arc sec. This position is 11.1 arc sec. from the center of the XRT error circle. The estimated magnitude is 19.32 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05.
Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:49:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.669d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
POINT_ROLL:      35.894d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  71205.10 SOD {19:46:45.10} UT,   877.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.596
N_STARS:         67
X_OFFSET:        567 [pixels]
Y_OFFSET:        42 [pixels]
X_MAX:           2006 [pixels]
Y_MAX:           1481 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00676423000msufc0877.fits
SUN_POSTN:       340.27d {+22h 41m 05s}   -8.32d {-08d 19' 28"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      213.01d {+14h 12m 03s}   -9.45d {-09d 27' 04"}
MOON_DIST:        88.55 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 27 Feb 16 19:50:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.669d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
POINT_ROLL:      35.894d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  71205.10 SOD {19:46:45.10} UT,   877.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.596
N_STARS:         67
X_OFFSET:        567 [pixels]
Y_OFFSET:        42 [pixels]
X_MAX:           2006 [pixels]
Y_MAX:           1481 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00676423000msufc0877.fits
SUN_POSTN:       340.27d {+22h 41m 05s}   -8.32d {-08d 19' 27"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      213.02d {+14h 12m 04s}   -9.45d {-09d 27' 07"}
MOON_DIST:        88.55 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [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:     Sat 27 Feb 16 19:51:05 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.669d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
ROLL:            35.894d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  71205.10 SOD {19:46:45.10} UT,   877.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     478295221
X_OFFSET:        1126 [pixels]
Y_OFFSET:        601 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1286
Y_GRB_POS:       761
BINNING_INDEX:   1
IM_URL:          sw00676423000msuni0893.fits
SUN_POSTN:       340.27d {+22h 41m 05s}   -8.32d {-08d 19' 27"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      213.02d {+14h 12m 06s}   -9.45d {-09d 27' 14"}
MOON_DIST:        88.56 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [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:     Sat 27 Feb 16 19:51:03 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     676423,   Seg_Num: 0
GRB_RA:          194.8074d {+12h 59m 13.77s} (J2000),
                 194.8997d {+12h 59m 35.92s} (current),
                 194.5233d {+12h 58m 05.58s} (1950)
GRB_DEC:         +78.6790d {+78d 40' 44.4"} (J2000),
                 +78.5921d {+78d 35' 31.3"} (current),
                 +78.9483d {+78d 56' 54.0"} (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:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  71179.00 SOD {19:46:19.00} UT,   850.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       340.27d {+22h 41m 05s}   -8.32d {-08d 19' 27"}
SUN_DIST:        107.64 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      213.02d {+14h 12m 06s}   -9.45d {-09d 27' 14"}
MOON_DIST:        88.60 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.44, 38.44 [deg] galactic lon,lat of the burst
ECL_COORDS:      118.89, 66.87 [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:     Sat 27 Feb 16 19:51:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     676423,   Seg_Num: 0
POINT_RA:        194.669d {+12h 58m 41s} (J2000)
POINT_DEC:       +78.623d {+78d 37' 24"} (J2000)
ROLL:            35.894d
IMG_START_DATE:  17445 TJD;    58 DOY;   16/02/27
IMG_START_TIME:  71205.10 SOD {19:46:45.10} UT,   877.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     478295221
X_OFFSET:        1126 [pixels]
Y_OFFSET:        601 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1286
Y_GRB_POS:       761
BINNING_INDEX:   1
IM_URL:          sw00676423000msuni0893.fits
SUN_POSTN:       340.27d {+22h 41m 05s}   -8.32d {-08d 19' 26"}
SUN_DIST:        107.70 [deg]   Sun_angle= 9.7 [hr] (West of Sun)
MOON_POSTN:      213.03d {+14h 12m 06s}   -9.45d {-09d 27' 17"}
MOON_DIST:        88.56 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      122.48, 38.50 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      119.01, 66.83 [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 #19099
E. Gorbovskoy, V. Lipunov,N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian The Instituto de Astrofisica de Canarias
D.Buckley, S. Potter, M.Kotze South African Astronomical Observatory
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Ural was pointed to the GRB160227A 30 after notice time and 115 sec after trigger time at 2016-02-27 19:34:03 UT. On our first (20s exposure) set we found 1 optical transient within SWIFT error-box (ra=12 59 08 dec=+78 38 19 r=0.050000) brighter then 17.6.
```
RA 12h 59m 14.13s
DEC +78d 40m 44.2s
  mag~17.36
```
The 5-sigma upper limit has been about 18.0 The message may be cited.
GCN Circular #19100
M. Andreev (Terskol Branch of INASAN), E. Mazaeva (IKI), V. Kozlov (IC AMER, NASU), A. Sergeev (Terskol Branch of INASAN), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 160227A (Siegel et al., GCN 19098) with Zeiss-600 telescope of Mt. Terskol observatory in R-filter starting on Feb. 27 (UT) 19:45:26. We obtained several images in R-filter. We clearly detect source in coordinates (J2000) 12 59 13.7 +78 40 44.9 which is apparently the afterglow of GRB GRB 160227A (Siegel et al., GCN 19098; Gorbovskoy et al., GCN 19099). The afterglow is clearly detected in a single images of 30 s exposure with brightness of ~19.0 magnitude in R-filter at Feb. 27 (UT) 19:49:36.
GCN Circular #19101
V. Nevskiy (ISON), V. Vikhrov(ISON), K. Polyakov (ISON), N. Rudenko (IAON), A. Kalinichenko (ISON), E. Mazaeva (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger collaboration:
We observed the field of GRB 160227A (Siegel et al., GCN 19098) with HGB-500 telescope (0.5-m, f/2) of ISON-Kislovodsk observatory starting on Feb. 27 (UT) 19:38:53, i.e. ~400 s after burst trigger. We obtained several unfiltered images of 60 s exposure. We clearly detect the afterglow of GRB 160227A (Siegel et al., GCN 19098; Gorbovskoy et al., GCN 19099; Andreev et al., GCN 19100). The afterglow brightness is ~18.0 magnitude at Feb. 27 (UT) 19:38:53.
GCN Circular #19103
T. Yoshii (Tokyo Tech), M. Nakajima, H. Negoro (Nihon U.), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Serino, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), N. Kawai, M. Arimoto, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, R. Imatani (Osaka U.), K. Tanaka, T. Masumitsu (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), Y. Tsuboi, S. Kanetou, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, D. Itoh, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Morii (ISM)
report on behalf of the MAXI team:
The MAXI/GSC detected an uncatalogued X-ray transient source at 19:35:13 UT on 2016 February 27. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (192.924 deg, 78.686 deg) = (12 51 41, +78 41 09) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.39 deg and 0.38 deg, respectively. The roll angle of long axis from the north direction is 46.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 130 +- 27 mCrab (4-10keV, 1 sigma error). Without assumptions on the source constancy,we obtain a rectangular error box for the transient source with the following corners:
```
(R.A., Dec) = (197.530 deg, 78.335 deg) = (13 10 07, +78 20 05) (J2000)
(R.A., Dec) = (194.899 deg, 77.788 deg) = (12 59 35, +77 47 15) (J2000)
(R.A., Dec) = (185.390 deg, 79.282 deg) = (12 21 33, +79 16 55) (J2000)
(R.A., Dec) = (187.705 deg, 79.931 deg) = (12 30 49, +79 55 52) (J2000)
```
The position is consistent with that of GRB 160227A (Siegel et al., GCN 19098), and the detected time is 185 sec after the BAT trigger.
There was no significant excess flux in the previous transit at 18:02 UT on 2016 February 27 and in the next transit at 21:07 UT on 2016 February 27 with an upper limit of 20 mCrab for each.
GCN Circular #19104
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 1604 s of XRT Photon Counting mode data and 1 UVOT images for GRB 160227A, 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 = 194.80719, +78.67917 which is equivalent to:
```
RA (J2000): 12h 59m 13.73s
Dec (J2000): +78d 40' 45.0"
```
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 #19105
P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester) and M.H. Siegel report on behalf of the Swift-XRT team:
We have analysed 6.9 ks of XRT data for GRB 160227A (Siegel et al. GCN Circ. 19098), from 147 s to 31.1 ks after the BAT trigger. The data comprise 691 s in Windowed Timing (WT) mode (the first 3 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. 19104).
The late-time light curve (from T0+5.9 ks) can be modelled with a power-law decay with a decay index of alpha=0.41 (+0.11, -0.10).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.79 (+/-0.03). The best-fitting absorption column is 7.3 (+0.9, -0.8) x 10^20 cm^-2, in excess of the Galactic value of 4.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.76 (+/-0.10) and a best-fitting absorption column of 6.6 (+2.8, -2.5) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     6.6 (+2.8, -2.5) x 10^20 cm^-2
Galactic foreground: 4.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.76 (+/-0.10)
```
If the light curve continues to decay with a power-law decay index of 0.41, the count rate at T+24 hours will be 0.15 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.7 x 10^-12 (6.3 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00676423.
This circular is an official product of the Swift-XRT team.
GCN Circular #19106
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+800 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160227A (trigger #676423) (Siegel et al., GCN Circ. 19098). The BAT ground-calculated position is RA, Dec = 195.034, 78.672 deg which is
```
  RA(J2000)  =  13h 00m 08.1s
  Dec(J2000) = +78d 40' 19.9"
```
with an uncertainty of 2.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~ T0-100 s and ends at ~ T0+270 s. There are roughly four pulses with peaks at ~ T0-100 s, ~ T0-20 s, ~ T0+100 s, and ~ T0+200 s, respectively. T90 (15-350 keV) is 316.5 +- 75.4 sec (estimated error including systematics).
The time-averaged spectrum from T-99.8 to T+236.2 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.75 +- 0.51, and Epeak of 65.8 +- 16.4 keV (chi squared 40.42 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.1 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+198.62 sec in the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.65 +- 0.10 (chi squared 51.62 for 57 d.o.f.). All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/676423/BA/
GCN Circular #19109
D. Xu (NAOC/CAS), J. P. U. Fynbo, D. Malesani (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), T. Petrushevska (Stockholm U.), P. M. Sorensen, J. Saario, J. Telting (NOT) report on behalf of a larger collaboration:
We observed the field of GRB 160227A (Siegel et al., GCN 19098) using the 2.56m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started at 20:19:12 UT on 2016-02-27 (i.e., 0.784 hr post-burst) and 2x120s R-band frames were obtained, followed by 2x1800s+1x1200s spectroscopy (i.e., at a median time of ~1.87 hr post-burst) covering 3200A - 9000A, all in a seeing of ~2.0 arcsec.
The previously reported optical afterglow (e.g., Siegel et al., GCN 19098; Gorbovskoy et al., GCN 19099) is clearly detected in our stacked R-band image, with R~19.3 mag calibrated with nearby USNO B1 stars.
Preliminary analysis of the spectrum shows a clear trough at the blue end of the spectral continuum, indicating Ly-alpha absorption from H I. We also detect several narrow absorption features, though at low signal-to-noise, which we interpret as due to, e.g., C II, Si II, O I, C II, Fe II, all consistent with a redshift of z = 2.38.
GCN Circular #19115
Y. Kitaoka, T. Sakamoto, A. Yoshida (AGU)
We observed the field of GRB 160227A detected by Swift (trigger #676423; Siegel et al., GCN Circ. 19098) with the 12-inch AGU Robotic Optical Monitor for Astrophysical object - Narrow (AROMA-N) located at the Sagamihara campus of Aoyama Gakuin University.
10 images of 60 sec exposures and 5 images of 180 sec exposures were taken in the R filter starting from February 27 19:36:28 (UT) about 260 seconds after the trigger and stopped on February 27 20:02:05 (UT). Because the target was a low elevation (44.4 deg at the start time) and the telescope was slightly out of focus, the quality of the obtained images was not ideal. We do not detect the optical afterglow both in the individual images and the stacked image. The estimated five sigma upper limit of the combined image (total exposure of 1500 sec) is ~16.4 mag using the USNO-B1 catalog.
GCN Circular #19116
V.Krushinski, I.Zalozhnich, A. Popov Ural State University, Kourovka
E. Gorbovskoy, V. Lipunov, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian The Instituto de Astrofisica de Canarias
Five telescopes of MASTER Net of robotic telescope participated in the observation of the GRB 160227A. Two telescopes detected prompt optical emission. We discovery very strong OT variations with time ~100 sec correlated with gamma ray flux (Sakamoto et al., 19106).
MASTER-Ural robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Ural was pointed to the GRB160227A 30 sec after notice time and 115 sec after trigger time at 2016-02-27 19:34:03 UT. On our first (20s exposure) set we found 1 optical transient within SWIFT error-box (Siegel et al GCN 19098; Gorbovskoy et al GCN 19099) at a position:
```
RA   12h 59m 14.13s
Dec +78d 40m 44.2s
```
With magnitude automatical magnitude ~ 17.3 We definetly see OT at a number of single and coadd images. OT was observed during ~ 1 hours. We see OT decay from 17.0 to 19.1 mag in the time interval from 115 to 2647 sec atger the trigger. The 5-sigma upper limit has been about 17.5 mag on first single image and up to 19.5 mag at on coadd images in later time.
MASTER-Kislovodsk robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB160227A (Siegel et al GCN 19098) 52 sec after notice time and 137 sec after trigger time at 2016-02-27 19:34:25 UT. On our first (30s exposure) set we marginaly see optical transient (Siegel et al GCN 19098, Gorbovskoy et al GCN 19099) within SWIFT error-box. OT also definetly seen at a number of coadd images. OT was observed for about 4 hours. We see OT decay from 18.1 to ~ 20.5 mag in the time interval from 152 to 12900 sec atger the trigger. The 5-sigma upper limit has been about 17.5 mag on first single image and up to 21.0 mag at on coadd images in later time.
MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB160227A 49 sec after notice time and 137 sec after trigger time at 2016-02-27 19:34:25 UT. On our first (30s exposure) set we haven`t found optical transient within SWIFT error-box. The observations started on evening sky (Sun altitude ~ -6 deg). Therefore, the first exposure upper limit is very low. We definetly see OT at a number of coadd images, starting ~ 1 hour after the trigger. OT was observed for about 2 hours. We see OT decay from 19.0 to 20.0 mag in the time interval from 3400 to 9200 sec atger the trigger. The 5-sigma upper limit has been about 14.5 mag (due to bright evening sky ) on first single image and up to 21.0 mag at on coadd images in later time.
MASTER-Tunka robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Astrophysical Center Tunka was pointed to the GRB160227A 17 sec after notice time and 103 sec after trigger time at 2016-02-27 19:33:51 UT. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box. The observations made on not very well weather condition and was finished 10 after GRB, due to snow coming. The 5-sigma upper limit has been about 15.3 mag on first single image.
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Blagoveschensk was pointed to the GRB160227A 8 sec after notice time and 93 sec after trigger time at 2016-02-27 19:33:41 UT. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box. The 5-sigma upper limit has been about 16.0 mag on first single image.
Out preliminary photometry results available at table 1 Light curve available here: http://master.sai.msu.ru/static/grb160227.png
Table 1.
```
T0-Tmig Expt.   Mag          Site            Coadd
-------|-------|------|---------------------|------
125     20      17.0     MASTER Ural
152     30      18.1     MASTER Kislovodsk
174     30      18.5     MASTER Ural
207     120     17.8     MASTER Kislovodsk     3
231     40      17.7     MASTER Ural
299     50      18.9     MASTER Ural
383     70      19.6     MASTER Ural
485     90      17.9     MASTER Ural
607     110     18.0     MASTER Ural
621     550     18.7     MASTER Kislovodsk     4
757     140     18.7     MASTER Ural
935     170     18.2     MASTER Ural
1133    180     19.1     MASTER Ural
1349    180     19.0     MASTER Ural
1566    180     18.9     MASTER Ural
1765    1080    18.9     MASTER Kislovodsk     6
1781    180     19.1     MASTER Ural
1998    180     19.1     MASTER Ural
2647    900     19.1     MASTER Ural           5
2789    360     19.7     MASTER Kislovodsk     2
3423    540     19.0     MASTER IAC            3
4261    900     19.2     MASTER IAC            5
4527    900     19.4     MASTER Kislovodsk     5
5966    1080    19.5     MASTER Kislovodsk     6
6401    1800    20.0     MASTER IAC           10
7771    3600    19.9     MASTER IAC           20
9196    1800    19.8     MASTER IAC           10
10608   1620    20.9     MASTER Kislovodsk     9
12824   1800    20.3     MASTER Kislovodsk    10
```
The message may be cited.

GCN Circular #19122
M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160227A 161 s after the BAT trigger (Siegel et al., GCN Circ. 19098). A source consistent with the XRT position (Osborne et al. GCN Circ. 19104) is detected in the initial UVOT exposures but had faded away in later exposures.
The preliminary UVOT position is:

   RA  (J2000) =  12:59:13.80 = 194.80750 (deg.)
   Dec (J2000) = +78:40:45.1  =  78.67920 (deg.)

with an estimated uncertainty of 0.46 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 (fc)         161          311          147         19.34 +/- 0.10
white              600         2418          341         19.80 +/- 0.13 
white             6755         8196          201        >20.82
v                  650         7366          400         19.40 +/- 0.25
b                  575         2393          194         19.71 +/- 0.35
b                 6550         8186          393        >20.10
u (fc)             319          569          245         19.44 +/- 0.20
u                  724         2368          174        >19.22
w1                 699         7776          540        >20.5
m2                1082         7570          432        >21.1
w2                1206         7161          294        >20.7

The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).

GCN Circular #19124
Myungshin Im, Changsu Choi, Gu Lim (CEOU/SNU), Soomin Jeong (SKKU/IAA-CSIC) on behalf of a larger collaboration
We observed the field of GRB 160227A (Palmer et al. GCN19098) using the 0.8m telescope at the McDonald Observatory. The observation started at 2016-02-28 03:03:38 UT, or about 7.5 hours after the BAT alert. We identify the afterglow at the location of the UVOT detection, and our preliminary analysis shows the afterglow at R ~ 20.8 +- 0.15 mag in a stacked image of 21 x 3 min frames. The mid-point of the observation is 2016-02-28 03:47. The photometry is calibrated against a star at RA=194.74877 and Dec=78.68984 (J2000) with R=15.72, taken from APASS catalog. A second epoch data was taken at about 6 hours later, and the analysis of the data is ongoing.
GCN Circular #19125
Soomin Jeong (SKKU/IAA-CSIC), Myungshin Im (SNU), Yuji Urata (NCU), Il H. Park (SKKU) on behalf of a larger collaboration:
We observed the field of GRB 160227A (Siegel, et al., GCN 19098) with the 1m telescope of Mt. Lemmon Optical Astronomy Observatory (LOAO) in Arizona. The series of images are taken in R- & B-filter starting on Feb. 28 05:11:27 UT (~ 9.7 hr post burst).=20 The optical counterpart is clearly detected in a median combined image of R at the previously reported optical afterglow position (e.g., Siegel et al., GCN 19098; Gorbovskoy et al., GCN 19099; Mazaeva et al., GCN19102). We confirmed marginal detection of OT in a median combined B.
The observed magnitudes are as following:
```
Mid Time(hr)     Exposure(s)       Filter       Magnitude

10.19         12x300            R          21.16 +/- 0.14
10.15          4x300             B           22.19 +/- 0.41
```
The fields are calibrated to the near by star at RA=194.74877, Dec=78.68984 (R2=3D15.84, USNO-B1.0).
GCN Circular #19404
Y.Ono (Tokyo Tech), S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. E. Nakagawa, Y. Sugawara (JAXA), T. Mihara, M. Sugizaki, M. Serino, W. Iwakiri, M. Shidatsu, J. Sugimoto, T. Takagi, M. Matsuoka (RIKEN), N. Kawai, N.Isobe, S.Sugita, T. Yoshii, Y. Tachibana, T. Fujiwara (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka (AGU), H. Tsunemi, R.Imatani (Osaka U.), H. Negoro, M. Nakajima, K. Tanaka, T. Masumitsu, T. Kawase (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team:
The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at UT 2016-05-09T09:04:16.
Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (312.131 deg, 75.810 deg) = (20 48 31, +75 48 36) (J2000) with a 90% C.L. statistical error of 0.06 deg and an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 1307 +- 69 mCrab (4-10keV, 1 sigma error). Without assumptions on the source constancy,we obtain a rectangular error box for the transient source with the following corners:
```
(310.897 deg, 75.728 deg) = (20 43 35, +75 43 40) (J2000)
(311.105 deg, 75.626 deg) = (20 44 25, +75 37 34) (J2000)
(313.379 deg, 75.887 deg) = (20 53 30, +75 53 14) (J2000)
(313.181 deg, 75.991 deg) = (20 52 43, +75 59 27) (J2000)
```
There was no significant excess flux in the previous transit at UT 2016-0509T07:32 with an upper limit of 20 mCrab.

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Jochen Greiner, last update: 09-May-2016 [Disclaimer]