Gamma-ray Burst 160501A

(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:     Sun 01 May 16 00:41:54 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     684679,   Seg_Num: 0
GRB_RA:          286.377d {+19h 05m 30s} (J2000),
                 286.613d {+19h 06m 27s} (current),
                 285.653d {+19h 02m 37s} (1950)
GRB_DEC:         -17.240d {-17d 14' 22"} (J2000),
                 -17.214d {-17d 12' 49"} (current),
                 -17.317d {-17d 18' 59"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=2312 [image_cnts]
TRIGGER_DUR:     64.000 [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:        17509 TJD;   122 DOY;   16/05/01
GRB_TIME:        2431.79 SOD {00:40:31.79} UT
GRB_PHI:         -118.41 [deg]
GRB_THETA:        19.54 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    11.34 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +1  +0  +0 +42  +0 
SUN_POSTN:        38.66d {+02h 34m 38s}  +15.15d {+15d 09' 08"}
SUN_DIST:        115.05 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.58d {+21h 34m 19s}  -11.97d {-11d 58' 00"}
MOON_DIST:        36.10 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.97,-10.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      285.69,  5.31 [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 = 358.11,20.56 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:43:20 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     684679,   Seg_Num: 0
GRB_RA:          286.3819d {+19h 05m 31.65s} (J2000),
                 286.6182d {+19h 06m 28.35s} (current),
                 285.6581d {+19h 02m 37.95s} (1950)
GRB_DEC:         -17.2403d {-17d 14' 25.0"} (J2000),
                 -17.2145d {-17d 12' 52.1"} (current),
                 -17.3171d {-17d 19' 01.6"} (1950)
GRB_ERROR:       5.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.08e-09 [erg/cm2/sec]
GRB_SIGNIF:      7.41 [sigma]
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2559.88 SOD {00:42:39.88} UT,   128.1 [sec] since BAT Trigger Time
TAM[0-3]:        327.68 237.23 261.70 243.64
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        38.66d {+02h 34m 38s}  +15.15d {+15d 09' 09"}
SUN_DIST:        115.05 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.59d {+21h 34m 23s}  -11.96d {-11d 57' 48"}
MOON_DIST:        36.11 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.97,-10.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      285.70,  5.31 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.29 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:43:29 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     684679,   Seg_Num: 0
GRB_RA:          286.3819d {+19h 05m 31.6s} (J2000),
                 286.6182d {+19h 06m 28.3s} (current),
                 285.6581d {+19h 02m 37.9s} (1950)
GRB_DEC:         -17.2403d {-17d 14' 25.0"} (J2000),
                 -17.2145d {-17d 12' 52.1"} (current),
                 -17.3171d {-17d 19' 01.6"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       55 [cnts]
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2559.88 SOD {00:42:39.88} UT,   128.1 [sec] since BAT Trigger Time
CENTROID_X:      280.68,  raw= 281  [pixels]
CENTROID_Y:      296.80,  raw= 297  [pixels]
ROLL:            81.02 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -2.34
GRB_POS_XRT_Z:   -58.01
IMAGE_URL:       sw00684679000msxps_rw.img
SUN_POSTN:        38.66d {+02h 34m 38s}  +15.15d {+15d 09' 09"}
SUN_DIST:        115.05 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.60d {+21h 34m 23s}  -11.96d {-11d 57' 47"}
MOON_DIST:        36.11 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.97,-10.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      285.70,  5.31 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:43:38 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     684679,   Seg_Num: 0
GRB_RA:          286.3819d {+19h 05m 31.6s} (J2000),
                 286.6182d {+19h 06m 28.3s} (current),
                 285.6581d {+19h 02m 37.9s} (1950)
GRB_DEC:         -17.2403d {-17d 14' 25.0"} (J2000),
                 -17.2145d {-17d 12' 52.1"} (current),
                 -17.3171d {-17d 19' 01.6"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       55 [cnts]
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2559.88 SOD {00:42:39.88} UT,   128.1 [sec] since BAT Trigger Time
CENTROID_X:      280.68,  raw= 281  [pixels]
CENTROID_Y:      296.80,  raw= 297  [pixels]
ROLL:            81.02 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -2.34
GRB_POS_XRT_Z:   -58.01
IMAGE_URL:       sw00684679000msxps_rw.img
SUN_POSTN:        38.66d {+02h 34m 38s}  +15.15d {+15d 09' 09"}
SUN_DIST:        115.05 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.60d {+21h 34m 23s}  -11.96d {-11d 57' 46"}
MOON_DIST:        36.11 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.97,-10.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      285.70,  5.31 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:44:26 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     684679,   Seg_Num: 0
GRB_RA:          286.377d {+19h 05m 30s} (J2000),
                 286.613d {+19h 06m 27s} (current),
                 285.653d {+19h 02m 37s} (1950)
GRB_DEC:         -17.240d {-17d 14' 22"} (J2000),
                 -17.214d {-17d 12' 49"} (current),
                 -17.317d {-17d 18' 59"} (1950)
GRB_DATE:        17509 TJD;   122 DOY;   16/05/01
GRB_TIME:        2431.79 SOD {00:40:31.79} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -118.41 [deg]
GRB_THETA:        19.54 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    11.34 [sigma]
LC_URL:          sw00684679000msb.lc
SUN_POSTN:        38.66d {+02h 34m 38s}  +15.15d {+15d 09' 10"}
SUN_DIST:        115.05 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.60d {+21h 34m 25s}  -11.96d {-11d 57' 39"}
MOON_DIST:        36.13 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.97,-10.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      285.69,  5.31 [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 = 358.11,20.56 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:46:20 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.366d {+19h 05m 28s} (J2000)
POINT_DEC:       -17.242d {-17d 14' 29"} (J2000)
POINT_ROLL:      81.019d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2568.26 SOD {00:42:48.26} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.799
N_STARS:         190
X_OFFSET:        560 [pixels]
Y_OFFSET:        496 [pixels]
X_MAX:           1519 [pixels]
Y_MAX:           1455 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00684679000msufc0136.fits
SUN_POSTN:        38.66d {+02h 34m 39s}  +15.15d {+15d 09' 11"}
SUN_DIST:        115.06 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.62d {+21h 34m 29s}  -11.96d {-11d 57' 24"}
MOON_DIST:        36.16 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:46:49 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.366d {+19h 05m 28s} (J2000)
POINT_DEC:       -17.242d {-17d 14' 29"} (J2000)
POINT_ROLL:      81.019d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2568.26 SOD {00:42:48.26} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.799
N_STARS:         190
X_OFFSET:        560 [pixels]
Y_OFFSET:        496 [pixels]
X_MAX:           1519 [pixels]
Y_MAX:           1455 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00684679000msufc0136.fits
SUN_POSTN:        38.66d {+02h 34m 39s}  +15.15d {+15d 09' 12"}
SUN_DIST:        115.06 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.63d {+21h 34m 30s}  -11.96d {-11d 57' 20"}
MOON_DIST:        36.16 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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 01 May 16 00:47:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.366d {+19h 05m 28s} (J2000)
POINT_DEC:       -17.242d {-17d 14' 29"} (J2000)
ROLL:            81.019d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2568.26 SOD {00:42:48.26} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     483756184
X_OFFSET:        909 [pixels]
Y_OFFSET:        812 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1069
Y_GRB_POS:       972
BINNING_INDEX:   1
IM_URL:          sw00684679000msuni0153.fits
SUN_POSTN:        38.66d {+02h 34m 39s}  +15.15d {+15d 09' 12"}
SUN_DIST:        115.06 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.64d {+21h 34m 33s}  -11.95d {-11d 57' 11"}
MOON_DIST:        36.17 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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:     Sun 01 May 16 00:48:09 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.366d {+19h 05m 28s} (J2000)
POINT_DEC:       -17.242d {-17d 14' 29"} (J2000)
ROLL:            81.019d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2568.26 SOD {00:42:48.26} UT,   136.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     483756184
X_OFFSET:        909 [pixels]
Y_OFFSET:        812 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1069
Y_GRB_POS:       972
BINNING_INDEX:   1
IM_URL:          sw00684679000msuni0153.fits
SUN_POSTN:        38.66d {+02h 34m 39s}  +15.15d {+15d 09' 13"}
SUN_DIST:        115.06 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.64d {+21h 34m 33s}  -11.95d {-11d 57' 09"}
MOON_DIST:        36.17 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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:     Sun 01 May 16 00:53:19 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 35"} (J2000)
POINT_ROLL:      81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2726.35 SOD {00:45:26.35} UT,   294.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.216
N_STARS:         190
X_OFFSET:        589 [pixels]
Y_OFFSET:        492 [pixels]
X_MAX:           1548 [pixels]
Y_MAX:           1451 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00684679000msufc0294.fits
SUN_POSTN:        38.67d {+02h 34m 40s}  +15.15d {+15d 09' 16"}
SUN_DIST:        115.07 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.69d {+21h 34m 45s}  -11.94d {-11d 56' 26"}
MOON_DIST:        36.22 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:53:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 35"} (J2000)
POINT_ROLL:      81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2726.35 SOD {00:45:26.35} UT,   294.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.216
N_STARS:         190
X_OFFSET:        589 [pixels]
Y_OFFSET:        492 [pixels]
X_MAX:           1548 [pixels]
Y_MAX:           1451 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00684679000msufc0294.fits
SUN_POSTN:        38.67d {+02h 34m 40s}  +15.15d {+15d 09' 17"}
SUN_DIST:        115.07 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.69d {+21h 34m 46s}  -11.94d {-11d 56' 23"}
MOON_DIST:        36.23 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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:     Sun 01 May 16 00:54:44 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 35"} (J2000)
ROLL:            81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2726.35 SOD {00:45:26.35} UT,   294.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     483756342
X_OFFSET:        909 [pixels]
Y_OFFSET:        812 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1069
Y_GRB_POS:       972
BINNING_INDEX:   1
IM_URL:          sw00684679000msuni0311.fits
SUN_POSTN:        38.67d {+02h 34m 40s}  +15.15d {+15d 09' 18"}
SUN_DIST:        115.07 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.70d {+21h 34m 48s}  -11.94d {-11d 56' 14"}
MOON_DIST:        36.24 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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:     Sun 01 May 16 00:55:03 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 35"} (J2000)
ROLL:            81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2726.35 SOD {00:45:26.35} UT,   294.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     483756342
X_OFFSET:        909 [pixels]
Y_OFFSET:        812 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1069
Y_GRB_POS:       972
BINNING_INDEX:   1
IM_URL:          sw00684679000msuni0311.fits
SUN_POSTN:        38.67d {+02h 34m 40s}  +15.15d {+15d 09' 18"}
SUN_DIST:        115.07 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.70d {+21h 34m 49s}  -11.94d {-11d 56' 11"}
MOON_DIST:        36.24 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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:     Sun 01 May 16 00:58:54 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 34"} (J2000)
POINT_ROLL:      81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  3304.40 SOD {00:55:04.40} UT,   872.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.764
N_STARS:         190
X_OFFSET:        349 [pixels]
Y_OFFSET:        252 [pixels]
X_MAX:           1788 [pixels]
Y_MAX:           1691 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00684679000msufc0872.fits
SUN_POSTN:        38.67d {+02h 34m 41s}  +15.16d {+15d 09' 21"}
SUN_DIST:        115.07 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.74d {+21h 34m 58s}  -11.93d {-11d 55' 39"}
MOON_DIST:        36.28 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 01 May 16 00:59:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 34"} (J2000)
POINT_ROLL:      81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  3304.40 SOD {00:55:04.40} UT,   872.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.764
N_STARS:         190
X_OFFSET:        349 [pixels]
Y_OFFSET:        252 [pixels]
X_MAX:           1788 [pixels]
Y_MAX:           1691 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00684679000msufc0872.fits
SUN_POSTN:        38.67d {+02h 34m 41s}  +15.16d {+15d 09' 21"}
SUN_DIST:        115.07 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.74d {+21h 34m 59s}  -11.93d {-11d 55' 36"}
MOON_DIST:        36.28 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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 01 May 16 01:00:25 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 34"} (J2000)
ROLL:            81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  3304.40 SOD {00:55:04.40} UT,   872.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     483756920
X_OFFSET:        908 [pixels]
Y_OFFSET:        811 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1068
Y_GRB_POS:       971
BINNING_INDEX:   1
IM_URL:          sw00684679000msuni0889.fits
SUN_POSTN:        38.67d {+02h 34m 41s}  +15.16d {+15d 09' 22"}
SUN_DIST:        115.08 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.76d {+21h 35m 01s}  -11.92d {-11d 55' 27"}
MOON_DIST:        36.29 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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 01 May 16 01:00:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     684679,   Seg_Num: 0
POINT_RA:        286.363d {+19h 05m 27s} (J2000)
POINT_DEC:       -17.243d {-17d 14' 34"} (J2000)
ROLL:            81.021d
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  3304.40 SOD {00:55:04.40} UT,   872.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     483756920
X_OFFSET:        908 [pixels]
Y_OFFSET:        811 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1068
Y_GRB_POS:       971
BINNING_INDEX:   1
IM_URL:          sw00684679000msuni0889.fits
SUN_POSTN:        38.67d {+02h 34m 41s}  +15.16d {+15d 09' 22"}
SUN_DIST:        115.08 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      323.76d {+21h 35m 02s}  -11.92d {-11d 55' 24"}
MOON_DIST:        36.29 [deg]
MOON_ILLUM:      41 [%]
GAL_COORDS:       18.96,-10.78 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      285.68,  5.31 [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 #19365
J. R. Cummings (NASA/UMBC), A. P. Beardmore (U Leicester), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), M. H. Siegel (PSU) and T. N. Ukwatta (LANL) report on behalf of the Swift Team:
At 00:40:31 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160501A (trigger=684679). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 286.377, -17.240 which is
```
   RA(J2000) = 19h 05m 30s
   Dec(J2000) = -17d 14' 22"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual for an image trigger, there is no clear variation visible in the immediately-available lightcurve data.
The XRT began observing the field at 00:42:39.8 UT, 128.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 286.38344, -17.24088 which is equivalent to:
```
   RA(J2000)  = 19h 05m 32.03s
   Dec(J2000) = -17d 14' 27.2"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 22 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.62 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.7 (+3.06/-2.65) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 1.08e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 136 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical upper limit is 19.6 magnitude. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The typical upper limit is 18.0. No correction has been made for the expected extinction corresponding to E(B-V) of 0.18.
Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.nasa.gov). 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 01 May 16 01:32:38 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     684679,   Seg_Num: 0
GRB_RA:          286.3834d {+19h 05m 32.01s} (J2000),
                 286.6197d {+19h 06m 28.71s} (current),
                 285.6596d {+19h 02m 38.31s} (1950)
GRB_DEC:         -17.2407d {-17d 14' 26.5"} (J2000),
                 -17.2149d {-17d 12' 53.5"} (current),
                 -17.3175d {-17d 19' 03.1"} (1950)
GRB_ERROR:       3.6 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17509 TJD;   122 DOY;   16/05/01
IMG_START_TIME:  2728.00 SOD {00:45:28.00} UT,   296.2 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        38.69d {+02h 34m 46s}  +15.16d {+15d 09' 46"}
SUN_DIST:        115.08 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      324.06d {+21h 36m 14s}  -11.85d {-11d 50' 59"}
MOON_DIST:        36.58 [deg]
MOON_ILLUM:      40 [%]
GAL_COORDS:       18.97,-10.80 [deg] galactic lon,lat of the burst
ECL_COORDS:      285.70,  5.31 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.11% < P(seren) < 0.58%.

GCN Circular #19366
Z. Cano (Univ. Iceland), N. Tanvir (Univ. Leicester), D. Malesani (DARK/NBI) & J. Saario (NOT) report on behalf of a larger collaboration:
We observed the field of GRB 160501A (Cummings et al.; GCN Circ. 19365) with the 2.5-m Nordic Optical Telescope equipped with the StanCam and the NOTCam, starting at 01:57 UT on 01 May 2016. We obtained 15 minutes in the I-band (StanCam) and 18 minutes in the H-band (NOTCam). In our co-added optical and NIR images we do not detect any new source within the XRT error circle to the following limits:
```
I > 22.3 mag
H > 19.0 mag
```
These upper limits (Vega) are for a single point source in the GRB field, they are calibrated against the USNO-B1 (optical) and 2MASS (NIR) catalogues, and they have not been corrected for foreground extinction.
GCN Circular #19367
V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov, Lomonosov Moscow State University, Sternberg Astronomical Institute
D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk
V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka
Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was pointed to the GRB160501A 24 sec after notice time and 106 sec after trigger time at 2016-05-01 00:42:21 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box (Cummings et al GCN 19365). The 5-sigma upper limit has been about 17.5 mag on single (20 s exposure) and 19.1 mag at coadd of first 10 images (with total exposure 780 s). Not very depth upper limits are explained by the proximity to the Moon. The message may be cited.
GCN Circular #19368
Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report:
We imaged the field of GRB 160501A detected by SWIFT (trigger 684679) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
The observations started 50 min after the GRB trigger. The elevation of the field increased from 20 degrees above horizon and weather conditions were good.
We co added images to increase detectivity:
```
t1(s) t2(s)  Rmag_lim  Site
3594  5526   18.5      TAROT Calern
5526  7863   18.5      TAROT Calern
```
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 18.9676 lat=-10.7948 and the galactic extinction in R band is about 1.0 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
GCN Circular #19369
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 2151 s of XRT Photon Counting mode data and 1 UVOT images for GRB 160501A, 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 = 286.38402, -17.24138 which is equivalent to:
```
RA (J2000): 19h 05m 32.16s
Dec (J2000): -17d 14' 29.0"
```
with an uncertainty of 1.9 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 #19370
Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos=E9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
We observed the field of GRB 160501A (Cummings et al., GCN Circ. 19365) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2016/05 1.33 to 2016/05 1.47 UTC (7.23 to 10.70 hours after the BAT trigger), obtaining a total of 1.73 hours exposure in the r and i bands and 0.66 hours exposure in the Z, Y, J, and H bands.
For a source within the enhanced Swift-XRT error circle (Evans et al., GCN Circ. 19369), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following 3-sigma upper limits:
```
 r	> 22.94
 i	> 22.76
 Z	> 21.69
 Y	> 21.22
 J	> 20.81
 H	> 19.90
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #19371
T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and J.R. Cummings report on behalf of the Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 160501A (Cummings et al. GCN Circ. 19365), from 118 s to 46.0 ks after the BAT trigger. The data comprise 161 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 19369).
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=2.76 (+/-0.16). At T+261 s the decay steepens to an alpha of 4.4 (+0.6, -0.3) before breaking again at T+918 s to a final decay with index alpha=0.26 (+0.36, -0.20).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.96 (+0.16, -0.15). The best-fitting absorption column is 2.9 (+/-0.4) x 10^21 cm^-2, in excess of the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.06 (+0.25, -0.18) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.6 (+0.7, -0.0) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.06 (+0.25, -0.18)
```
If the light curve continues to decay with a power-law decay index of 0.26, the count rate at T+24 hours will be 7.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x 10^-13 (3.6 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/00684679.
This circular is an official product of the Swift-XRT team.
GCN Circular #19372
A. A. Breeveld (UCL-MSSL) and J. R. Cummings (NASA/UMBC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160501A 136s after the BAT trigger (Cummings et al., GCN Circ. 19365). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 19369) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           136          286          147         >20.3
u_FC               295          544          246         >19.7
white              575         1543          245         >21.1
v                  625         1594          117         >18.9
b                  551         1518           97         >19.9
w1                 674         1643          117         >19.2
m2                 649         1618          117         >19.7
w2                 600         1569          117         >19.2
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.18 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #19373
W. Fong and P. Milne (University of Arizona) report:
"We observed the field of GRB 160501A (Cummings et al., GCN 19365) with the Wide Field Camera (WFCAM) mounted on the 3.8-m United Kingdom Infrared Telescope (UKIRT) on Mauna Kea beginning on 2016 May 1.533 UT (12.1 hr post-burst). We obtained observations in the J- and K-bands in 0.75" seeing. Using the quick-look pipeline ORAC-DR, we do not detect any near-IR source in or around enhanced X-ray position (Evans et al., GCN 19369). Calibrated to 2MASS, we therefore place 3-sigma limits of J(AB)>19.7 mag and K(AB)>19.2 mag on the near-IR afterglow of GRB 160501A at 12.1 hr post-burst. We note that this analysis is preliminary and a final reduction of the images are expected to be at least ~1.5 mag deeper.
We thank Tim Carroll, Watson Varricatt and Tom Kerr for their assistance in planning and executing these observations."
GCN Circular #19374
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 160501A (Cummings et al., GCNC 19365) 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 2016-05-01 17:18:31 UT (~16.6 h after the burst). We did not find any new point source within the enhanced XRT circle (Evans et al., GCNC 19369) in all the three bands.
Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration.
```
#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc     Ic
-----------------------------------------------------
0.73280    18:15:45    5460.0   >19.4  >19.1  >18.3
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
```
GCN Circular #19375
J. Bodensteiner, F. Knust, T. Schweyer , J. Greiner (all MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 160501A (Swift trigger 684679; Cummings et al., GCN #19365) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 07:15 UT on 2016-05-01, 6h 35min after the GRB trigger. They were performed at an average seeing of 1.3" and at an average airmass of 1.09.
We do not detect a source within the Swift-XRT error circle reported by Evans et al. (GCN #19369) down to
```
g' > 24.8 mag,
r' > 24.5 mag,
i' > 23.8 mag,
z' > 23.9 mag,
J > 21.1 mag,
H > 20.7 mag, and
K > 19.1 mag.
(all in AB).
```
The given limits are derived based on calibration against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.18 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #19376
C. B. Markwardt (GSFC), 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), 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 160501A (trigger #684679) (Cummings, et al., GCN Circ. 19365). The BAT ground-calculated position is RA, Dec = 286.389, -17.249 deg which is
```
   RA(J2000)  =  19h 05m 33.2s 
   Dec(J2000) = -17d 14' 54.8" 
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 81%.
The mask-weighted light curve a broad peak starting from T-80 sec, peaking at T+50 sec and ending at T+90 sec. T90 (15-350 keV) is 118 +- 19 sec (estimated error including systematics).
The time-averaged spectrum from T-54.3 to T+72.6 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.6 +- 1.3, and Epeak of 28 +- 9 keV (chi squared 54.26 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 9.5 +- 1.3 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T-54.38 sec in the 15-150 keV band is 0.5 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.4 +- 0.2 (chi squared 63.09 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/684679/BA/
GCN Circular #19378
B. E. Cobb (GWU) reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 160501A (GCN 19365, Cummings et al.) with a mid-exposure time of 4.3 hours post-burst (2016-05-01 05:01 UT). Total summed exposure times amounted to 36 minutes in I and 30 minutes in J.
No source is detected at the position of the X-ray afterglow (GCN 19365, Cummings et al; GCN 19369, Evans et al.) to approximate limiting magnitudes of I > 20.7 and J > 18.5. Magnitudes are calibrated using USNO-B1.0 stars in I, and 2MASS stars in J.

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Jochen Greiner, last update: 03-May-2016 [Disclaimer]