Gamma-ray Burst 150530A

(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 30 May 15 11:42:59 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     642018,   Seg_Num: 0
GRB_RA:          327.523d {+21h 50m 06s} (J2000),
                 327.649d {+21h 50m 36s} (current),
                 327.118d {+21h 48m 28s} (1950)
GRB_DEC:         +57.490d {+57d 29' 25"} (J2000),
                 +57.563d {+57d 33' 46"} (current),
                 +57.256d {+57d 15' 22"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3287 [cnts]    Image_Peak=148 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   150     E_range: 25-100 keV
BKG_INTEN:       17250 [cnts]
BKG_TIME:        42122.35 SOD {11:42:02.35} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17172 TJD;   150 DOY;   15/05/30
GRB_TIME:        42138.22 SOD {11:42:18.22} UT
GRB_PHI:         165.97 [deg]
GRB_THETA:        48.42 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     23.76 [sigma]
IMAGE_SIGNIF:    9.11 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +1 -23  +0 
SUN_POSTN:        67.05d {+04h 28m 12s}  +21.76d {+21d 45' 39"}
SUN_DIST:         76.61 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.64d {+13h 58m 34s}  -10.09d {-10d 05' 37"}
MOON_DIST:       113.32 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.43,  2.77 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        8.86, 62.69 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 336.71,20.03 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(3.0<100sec) coincident with the FERMI_GBM event (trignum=454678938).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 30 May 15 11:42:43 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      44
TRIGGER_NUM:     454678938
GRB_RA:          293.800d {+19h 35m 12s} (J2000),
                 293.846d {+19h 35m 23s} (current),
                 293.650d {+19h 34m 36s} (1950)
GRB_DEC:         +62.600d {+62d 36' 00"} (J2000),
                 +62.635d {+62d 38' 05"} (current),
                 +62.488d {+62d 29' 17"} (1950)
GRB_ERROR:       14.87 [deg radius, statistical plus systematic]
GRB_INTEN:       94 [cnts/sec]
DATA_SIGNIF:     5.80 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        17172 TJD;   150 DOY;   15/05/30
GRB_TIME:        42135.61 SOD {11:42:15.61} UT
GRB_PHI:         280.00 [deg]
GRB_THETA:        30.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      1.77
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      84%  GRB
2nd_MOST_LIKELY:  13%  Generic SGR
DETECTORS:       0,0,0, 1,0,0, 1,0,0, 0,0,0, 0,0,
SUN_POSTN:        67.05d {+04h 28m 12s}  +21.76d {+21d 45' 39"}
SUN_DIST:         87.88 [deg]   Sun_angle= 8.9 [hr] (West of Sun)
MOON_POSTN:      209.64d {+13h 58m 34s}  -10.09d {-10d 05' 35"}
MOON_DIST:        96.31 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:       94.37, 19.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      349.87, 79.13 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn150530488/quicklook/glg_lc_medres34_bn150530488.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 128.92,18.32 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 30 May 15 11:42:52 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      57
TRIGGER_NUM:     454678938
GRB_RA:          322.317d {+21h 29m 16s} (J2000),
                 322.436d {+21h 29m 45s} (current),
                 321.930d {+21h 27m 43s} (1950)
GRB_DEC:         +56.117d {+56d 07' 00"} (J2000),
                 +56.185d {+56d 11' 05"} (current),
                 +55.897d {+55d 53' 49"} (1950)
GRB_ERROR:       6.37 [deg radius, statistical plus systematic]
GRB_INTEN:       335 [cnts/sec]
DATA_SIGNIF:     20.40 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        17172 TJD;   150 DOY;   15/05/30
GRB_TIME:        42135.61 SOD {11:42:15.61} UT
GRB_PHI:         288.00 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.90
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      94%  GRB
2nd_MOST_LIKELY:   4%  Cyg X-1
DETECTORS:       0,0,0, 1,0,0, 1,0,0, 0,0,0, 0,0,
SUN_POSTN:        67.05d {+04h 28m 12s}  +21.76d {+21d 45' 39"}
SUN_DIST:         79.77 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:      209.64d {+13h 58m 34s}  -10.09d {-10d 05' 36"}
MOON_DIST:       110.97 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:       97.38,  3.63 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        2.28, 63.80 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn150530488/quicklook/glg_lc_medres34_bn150530488.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 128.92,18.32 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 30 May 15 11:43:08 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     454678938
GRB_RA:          328.610d {+21h 54m 26s} (J2000),
                 328.746d {+21h 54m 59s} (current),
                 328.168d {+21h 52m 40s} (1950)
GRB_DEC:         +53.850d {+53d 51' 00"} (J2000),
                 +53.923d {+53d 55' 24"} (current),
                 +53.613d {+53d 36' 46"} (1950)
GRB_ERROR:       3.60 [deg radius, statistical only]
DATA_SIGNIF:     25.30 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        17172 TJD;   150 DOY;   15/05/30
GRB_TIME:        42135.61 SOD {11:42:15.61} UT
GRB_PHI:         290.00 [deg]
GRB_THETA:        49.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:        67.05d {+04h 28m 12s}  +21.76d {+21d 45' 39"}
SUN_DIST:         77.25 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.64d {+13h 58m 35s}  -10.09d {-10d 05' 38"}
MOON_DIST:       115.06 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:       98.62, -0.45 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        4.46, 59.66 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2015/bn150530488/quicklook/glg_lc_medres34_bn150530488.gif
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(3.0<100sec) coincident with the SWIFT_BAT event (trignum=642018).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:44:15 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.497d {+21h 49m 59s} (J2000)
POINT_DEC:       +57.486d {+57d 29' 09"} (J2000)
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42240.87 SOD {11:44:00.87} UT,   102.7 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:45:55 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     642018,   Seg_Num: 0
GRB_RA:          327.523d {+21h 50m 06s} (J2000),
                 327.649d {+21h 50m 36s} (current),
                 327.118d {+21h 48m 28s} (1950)
GRB_DEC:         +57.490d {+57d 29' 25"} (J2000),
                 +57.563d {+57d 33' 46"} (current),
                 +57.256d {+57d 15' 22"} (1950)
GRB_DATE:        17172 TJD;   150 DOY;   15/05/30
GRB_TIME:        42138.22 SOD {11:42:18.22} UT
TRIGGER_INDEX:   150
GRB_PHI:         165.97 [deg]
GRB_THETA:        48.42 [deg]
DELTA_TIME:      13.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     23.76 [sigma]
IMAGE_SIGNIF:    9.11 [sigma]
LC_URL:          sw00642018000msb.lc
SUN_POSTN:        67.05d {+04h 28m 12s}  +21.76d {+21d 45' 40"}
SUN_DIST:         76.61 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.67d {+13h 58m 40s}  -10.10d {-10d 06' 01"}
MOON_DIST:       113.31 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.43,  2.77 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        8.86, 62.69 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 336.71,20.03 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:48:05 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     642018,   Seg_Num: 0
GRB_RA:          327.5102d {+21h 50m 02.44s} (J2000),
                 327.6353d {+21h 50m 32.46s} (current),
                 327.1048d {+21h 48m 25.15s} (1950)
GRB_DEC:         +57.5165d {+57d 30' 59.4"} (J2000),
                 +57.5889d {+57d 35' 20.0"} (current),
                 +57.2822d {+57d 16' 55.9"} (1950)
GRB_ERROR:       4.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42248.00 SOD {11:44:08.00} UT,   109.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        67.05d {+04h 28m 12s}  +21.76d {+21d 45' 41"}
SUN_DIST:         76.61 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.69d {+13h 58m 45s}  -10.11d {-10d 06' 19"}
MOON_DIST:       113.29 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.44,  2.79 [deg] galactic lon,lat of the burst
ECL_COORDS:        8.89, 62.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:48:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.497d {+21h 49m 59s} (J2000)
POINT_DEC:       +57.486d {+57d 29' 09"} (J2000)
POINT_ROLL:      70.223d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42244.23 SOD {11:44:04.23} UT,   106.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.360
N_STARS:         99
X_OFFSET:        562 [pixels]
Y_OFFSET:        499 [pixels]
X_MAX:           1521 [pixels]
Y_MAX:           1458 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw00642018000msufc0106.fits
SUN_POSTN:        67.05d {+04h 28m 13s}  +21.76d {+21d 45' 41"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.69d {+13h 58m 46s}  -10.11d {-10d 06' 25"}
MOON_DIST:       113.30 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:49:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.497d {+21h 49m 59s} (J2000)
POINT_DEC:       +57.486d {+57d 29' 09"} (J2000)
POINT_ROLL:      70.223d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42244.23 SOD {11:44:04.23} UT,   106.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.360
N_STARS:         99
X_OFFSET:        562 [pixels]
Y_OFFSET:        499 [pixels]
X_MAX:           1521 [pixels]
Y_MAX:           1458 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw00642018000msufc0106.fits
SUN_POSTN:        67.05d {+04h 28m 13s}  +21.76d {+21d 45' 41"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.70d {+13h 58m 47s}  -10.11d {-10d 06' 30"}
MOON_DIST:       113.29 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [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 30 May 15 11:50:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.497d {+21h 49m 59s} (J2000)
POINT_DEC:       +57.486d {+57d 29' 09"} (J2000)
ROLL:            70.223d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42244.23 SOD {11:44:04.23} UT,   106.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     454679057
X_OFFSET:        881 [pixels]
Y_OFFSET:        818 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       978
BINNING_INDEX:   1
IM_URL:          sw00642018000msuni0120.fits
SUN_POSTN:        67.05d {+04h 28m 13s}  +21.76d {+21d 45' 42"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.71d {+13h 58m 50s}  -10.11d {-10d 06' 39"}
MOON_DIST:       113.29 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [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 30 May 15 11:50:41 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.497d {+21h 49m 59s} (J2000)
POINT_DEC:       +57.486d {+57d 29' 09"} (J2000)
ROLL:            70.223d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42244.23 SOD {11:44:04.23} UT,   106.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     454679057
X_OFFSET:        881 [pixels]
Y_OFFSET:        818 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       978
BINNING_INDEX:   1
IM_URL:          sw00642018000msuni0120.fits
SUN_POSTN:        67.05d {+04h 28m 13s}  +21.76d {+21d 45' 42"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.71d {+13h 58m 50s}  -10.11d {-10d 06' 41"}
MOON_DIST:       113.29 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:56:21 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.499d {+21h 50m 00s} (J2000)
POINT_DEC:       +57.485d {+57d 29' 05"} (J2000)
POINT_ROLL:      70.224d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42457.59 SOD {11:47:37.59} UT,   319.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.837
N_STARS:         71
X_OFFSET:        322 [pixels]
Y_OFFSET:        259 [pixels]
X_MAX:           1761 [pixels]
Y_MAX:           1698 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00642018000msufc0319.fits
SUN_POSTN:        67.06d {+04h 28m 14s}  +21.76d {+21d 45' 44"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.76d {+13h 59m 01s}  -10.12d {-10d 07' 28"}
MOON_DIST:       113.28 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 30 May 15 11:56:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.499d {+21h 50m 00s} (J2000)
POINT_DEC:       +57.485d {+57d 29' 05"} (J2000)
POINT_ROLL:      70.224d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42457.59 SOD {11:47:37.59} UT,   319.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        2.837
N_STARS:         71
X_OFFSET:        322 [pixels]
Y_OFFSET:        259 [pixels]
X_MAX:           1761 [pixels]
Y_MAX:           1698 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00642018000msufc0319.fits
SUN_POSTN:        67.06d {+04h 28m 14s}  +21.76d {+21d 45' 44"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.76d {+13h 59m 02s}  -10.13d {-10d 07' 31"}
MOON_DIST:       113.28 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [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 30 May 15 11:57:02 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     642018,   Seg_Num: 0
GRB_RA:          327.5108d {+21h 50m 02.59s} (J2000),
                 327.6359d {+21h 50m 32.61s} (current),
                 327.1054d {+21h 48m 25.29s} (1950)
GRB_DEC:         +57.5163d {+57d 30' 58.6"} (J2000),
                 +57.5887d {+57d 35' 19.3"} (current),
                 +57.2820d {+57d 16' 55.1"} (1950)
GRB_ERROR:       3.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42248.00 SOD {11:44:08.00} UT,   109.8 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        67.06d {+04h 28m 14s}  +21.76d {+21d 45' 44"}
SUN_DIST:         76.61 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.76d {+13h 59m 03s}  -10.13d {-10d 07' 33"}
MOON_DIST:       113.27 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.44,  2.79 [deg] galactic lon,lat of the burst
ECL_COORDS:        8.89, 62.71 [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 30 May 15 11:57:53 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.499d {+21h 50m 00s} (J2000)
POINT_DEC:       +57.485d {+57d 29' 05"} (J2000)
ROLL:            70.224d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42457.59 SOD {11:47:37.59} UT,   319.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     454679271
X_OFFSET:        881 [pixels]
Y_OFFSET:        818 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       978
BINNING_INDEX:   1
IM_URL:          sw00642018000msuni0333.fits
SUN_POSTN:        67.06d {+04h 28m 14s}  +21.76d {+21d 45' 44"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.77d {+13h 59m 04s}  -10.13d {-10d 07' 40"}
MOON_DIST:       113.28 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [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 30 May 15 11:58:03 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     642018,   Seg_Num: 0
POINT_RA:        327.499d {+21h 50m 00s} (J2000)
POINT_DEC:       +57.485d {+57d 29' 05"} (J2000)
ROLL:            70.224d
IMG_START_DATE:  17172 TJD;   150 DOY;   15/05/30
IMG_START_TIME:  42457.59 SOD {11:47:37.59} UT,   319.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     454679271
X_OFFSET:        881 [pixels]
Y_OFFSET:        818 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1041
Y_GRB_POS:       978
BINNING_INDEX:   1
IM_URL:          sw00642018000msuni0333.fits
SUN_POSTN:        67.06d {+04h 28m 14s}  +21.76d {+21d 45' 44"}
SUN_DIST:         76.63 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      209.77d {+13h 59m 05s}  -10.13d {-10d 07' 42"}
MOON_DIST:       113.28 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      100.42,  2.77 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:        8.83, 62.69 [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 #17888
R. L. C. Starling (U Leicester), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC) and K. L. Page (U Leicester) report on behalf of the Swift Team:
At 11:42:18 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150530A (trigger=642018). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 327.523, +57.490 which is
```
   RA(J2000) = 21h 50m 06s
   Dec(J2000) = +57d 29' 25"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak with some structure with a duration of about 10 sec. The peak count rate was ~2500 counts/sec (15-350 keV).
The XRT began observing the field at 11:44:00.8 UT, 102.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 327.5109, 57.5164 which is equivalent to:
```
   RA(J2000)  = 21h 50m 02.61s
   Dec(J2000) = +57d 30' 58.9"
```
with an uncertainty of 3.3 arcseconds (radius, 90% containment). This location is 96 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. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.00 x 10^22 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 106 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 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain extinction expected.
Burst Advocate for this burst is R. L. C. Starling (rlcs1 AT star.le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #17889
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 418 s of XRT Photon Counting mode data and 1 UVOT images for GRB 150530A, 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 = 327.51297, +57.51681 which is equivalent to:
```
RA (J2000): 21h 50m 3.11s
Dec (J2000): +57d 31' 00.5"
```
with an uncertainty of 2.2 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 #17890
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), R. L. C. Starling (U Leicester), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from recent telemetry downlinks, we report further analysis of BAT GRB 150530A (trigger #642018) (Strling, et al., GCN Circ. 17888). The BAT ground-calculated position is RA, Dec = 327.511, 57.519 deg, which is
```
   RA(J2000)  =  21h 50m 02.6s 
   Dec(J2000) = +57d 31' 07.4" 
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 17%.
The mask-weighted light curve shows a couple overlapping peaks starting at ~T-10 sec, peaking at ~T+2 sec, and ending at ~T+40 sec. T90 (15-350 keV) is 6.62 +- 0.84 sec (estimated error including systematics).
The time-averaged spectrum from T-4.21 to T+3.49 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.49 +- 0.11. The fluence in the 15-150 keV band is 1.8 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.48 sec in the 15-150 keV band is 4.1 +- 0.6 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/642018/BA/
GCN Circular #17891
Yu H.-F. (MPE), Younes G. (USRA at GWU), and Meegan C. (UAH) report on behalf of the Fermi GBM Team:
"At 11:42:15.61 UT, on 2015 May 30, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150530A (trigger 454678938 / 150530488) which was also detected by Swift (Starling et al. 2015, GCN 17888). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is about 46 degrees.
The GBM light curve consists of two peaks with a duration (T90) of 7 s (50-300 keV). The time-averaged spectrum from T0-4.6 s to T0+6.7 s is well fit by a BAND function with Epeak = 126 +/- 14 keV, alpha = -0.8 +/- 0.1, and beta = -2.4 +/- 0.2.
The event fluence (10-1000 keV) in this time interval is (4.1 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+2.8 s in the 10-1000 keV band is 6.7 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #17892
M. De Pasquale (UCL-MSSL) and R. L. C. Starling (U Leicester)report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150530A 106 s after the BAT trigger (Starling et al., GCN Circ. 17888). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 17889) 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           106          256          147 >20.1
u_FC               319          562          238 >19.2
white              106         5690          541 >21.0
v                 4465         6101          393 >19.3
b                 3849         5485          393 >20.4
u                  319         5280          435 >19.7
w1                4875         5075          197 >19.5
m2                4670         6306          393 >19.9
w2                4260         5896          393 >20.1
```
The magnitudes in the table are not corrected for the strong Galactic extinction due to the reddening of E(B-V) = 1.81 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #17893
A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC) and R.L.C. Starling report on behalf of the Swift-XRT team:
We have analysed 9.2 ks of XRT data for GRB 150530A (Starling et al. GCN Circ. 17888), from 90 s to 22.6 ks after the BAT trigger. The data comprise 6 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 17889).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.98 (+/-0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.9 (+/-0.5). The best-fitting absorption column is 2.2 (+0.9, -0.8) x 10^22 cm^-2, in excess of the Galactic value of 1.0 x 10^22 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 6.6 x 10^-11 (1.3 x 10^-10) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.2 (+0.9, -0.8) x 10^22 cm^-2
Galactic foreground: 1.0 x 10^22 cm^-2
Excess significance: 2.7 sigma
Photon index:	     1.9 (+/-0.5)
```
If the light curve continues to decay with a power-law decay index of 0.98, the count rate at T+24 hours will be 1.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x 10^-13 (2.2 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00642018.
This circular is an official product of the Swift-XRT team.
GCN Circular #17894
Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enr= ico Ramirez-Ruiz (UCSC), Jos=C3=A9 A. de Diego (UNAM), Leonid Georgiev (UNAM)= , Jes=C3=BAs Gonz=C3=A1lez (UNAM), Carlos Rom=C3=A1n-Z=C3=BA=C3=B1iga (UNAM= ), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 150530A (Starling et al., GCN 17888) with th= e Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=C3=B3mico Nacion= al on Sierra San Pedro M=C3=A1rtir from 2015/05 31.32 to 2015/05 31.45 UTC (20.= 08 to 23.21 hours after the BAT trigger), obtaining a total of 2.49 hours exposure in the r, i, and z bands.
For a source within the Swift-XRT error circle, in comparison with 2MASS,= we obtain the following upper limits (3-sigma):
```
  r > 24.42
  i > 24.18
  z > 20.44
```
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=C3=B3mico Nacional in San P= edro M=C3=A1rtir.
GCN Circular #17900
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
The long-duration GRB 150530A (Swift-BAT trigger #642018: Starling et al., GCN 17888; Markwardt et al., GCN 17890; Fermi GBM detection: Yu, Younes and Meegan, GCN 17891) triggered Konus-Wind at T0=42136.529 s UT (11:42:16.529).
The burst light curve shows a single pulse lasting from ~T0-4 s to ~T0+6 s. The emission is seen up to ~1.2 MeV.
As observed by Konus-Wind, the burst had a fluence of 2.54(-0.26,+0.28)x10^-6 erg/cm2, and a 64-ms peak energy flux, measured from T0+0.082 s, of 1.06(-0.43,+0.43)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 1.2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.63(-0.38,+0.46), and Ep = 114(-17,+23) keV (chi2 = 59/58 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -3.07 (chi2 = 59/57 dof).
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150530_T42136/
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.

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Jochen Greiner, last update: 03-Jun-2015 [Disclaimer]