Gamma-ray Burst 090621

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:23:37 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     355303,   Seg_Num: 0
GRB_RA:           10.986d {+00h 43m 57s} (J2000),
                  11.126d {+00h 44m 30s} (current),
                  10.250d {+00h 41m 00s} (1950)
GRB_DEC:         +61.968d {+61d 58' 04"} (J2000),
                 +62.020d {+62d 01' 11"} (current),
                 +61.694d {+61d 41' 39"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       30427 [cnts]    Image_Peak=515 [image_cnts]
TRIGGER_DUR:     8.192 [sec] 
TRIGGER_INDEX:   477     E_range: 25-100 keV
BKG_INTEN:       220576 [cnts]
BKG_TIME:        15675.15 SOD {04:21:15.15} UT
BKG_DUR:         64 [sec]
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15763.15 SOD {04:22:43.15} UT
GRB_PHI:         -35.83 [deg]
GRB_THETA:        27.62 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.28 [sigma]
IMAGE_SIGNIF:    7.80 [sigma]
MERIT_PARAMS:     +1  +0  +0  +3  +2  -2  +0  +1 -43  +0 
SUN_POSTN:        89.94d {+05h 59m 45s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.37d {+04h 17m 29s}  +25.55d {+25d 33' 04"}
MOON_DIST:        50.64 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       43.20, 50.73 [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 = 329.50,15.59 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:24:47 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.997d {+00h 43m 59s} (J2000)
POINT_DEC:       +61.968d {+61d 58' 03"} (J2000)
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  15880.46 SOD {04:24:40.46} UT,   117.3 [sec] since BAT Trigger Time
COUNTS:          11    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:26:30 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     355303,   Seg_Num: 0
GRB_RA:           10.986d {+00h 43m 57s} (J2000),
                  11.126d {+00h 44m 30s} (current),
                  10.250d {+00h 41m 00s} (1950)
GRB_DEC:         +61.968d {+61d 58' 04"} (J2000),
                 +62.020d {+62d 01' 11"} (current),
                 +61.694d {+61d 41' 39"} (1950)
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15763.15 SOD {04:22:43.15} UT
TRIGGER_INDEX:   477
GRB_PHI:         -35.83 [deg]
GRB_THETA:        27.62 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     8.192 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.28 [sigma]
IMAGE_SIGNIF:    7.80 [sigma]
LC_URL:          sw00355303000msb.lc
SUN_POSTN:        89.94d {+05h 59m 45s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.40d {+04h 17m 37s}  +25.55d {+25d 33' 17"}
MOON_DIST:        50.65 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       43.20, 50.73 [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 = 329.50,15.59 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:27:34 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     267251196
GRB_RA:          355.770d {+23h 43m 05s} (J2000),
                 355.882d {+23h 43m 32s} (current),
                 355.183d {+23h 40m 44s} (1950)
GRB_DEC:         +67.730d {+67d 43' 48"} (J2000),
                 +67.783d {+67d 46' 57"} (current),
                 +67.452d {+67d 27' 09"} (1950)
GRB_ERROR:       8.03 [deg radius, statistical only]
DATA_SIGNIF:     7.80 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15994.49 SOD {04:26:34.49} UT
GRB_PHI:         156.00 [deg]
GRB_THETA:        18.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         69.90 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:       64.42d {+04h 17m 40s}  +25.56d {+25d 33' 22"}
MOON_DIST:        58.39 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      116.51,  5.72 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       42.18, 59.34 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:27:05 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      68
TRIGGER_NUM:     267251196
GRB_RA:            3.367d {+00h 13m 28s} (J2000),
                   3.494d {+00h 13m 58s} (current),
                   2.699d {+00h 10m 48s} (1950)
GRB_DEC:         +61.200d {+61d 12' 00"} (J2000),
                 +61.253d {+61d 15' 09"} (current),
                 +60.922d {+60d 55' 19"} (1950)
GRB_ERROR:       14.27 [deg radius, statistical plus systematic]
GRB_INTEN:       92 [cnts/sec]
DATA_SIGNIF:     7.80 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15994.49 SOD {04:26:34.49} UT
GRB_PHI:         180.00 [deg]
GRB_THETA:        15.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.69
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      79%  GRB
2nd_MOST_LIKELY:  13%  Generic SGR
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         67.91 [deg]   Sun_angle= 5.8 [hr] (West of Sun)
MOON_POSTN:       64.41d {+04h 17m 39s}  +25.56d {+25d 33' 20"}
MOON_DIST:        53.91 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      118.37, -1.34 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       37.91, 52.44 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 62.30,25.08 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:27:00 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      57
TRIGGER_NUM:     267251196
GRB_RA:          351.017d {+23h 24m 04s} (J2000),
                 351.115d {+23h 24m 28s} (current),
                 350.498d {+23h 21m 59s} (1950)
GRB_DEC:         +69.933d {+69d 55' 60"} (J2000),
                 +69.985d {+69d 59' 07"} (current),
                 +69.659d {+69d 39' 31"} (1950)
GRB_ERROR:       15.43 [deg radius, statistical plus systematic]
GRB_INTEN:       83 [cnts/sec]
DATA_SIGNIF:     7.40 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15994.49 SOD {04:26:34.49} UT
GRB_PHI:         150.00 [deg]
GRB_THETA:        20.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.26
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         71.00 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:       64.41d {+04h 17m 38s}  +25.56d {+25d 33' 19"}
MOON_DIST:        60.39 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      115.52,  8.33 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       43.75, 62.02 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 62.30,25.08 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:27:50 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      67
TRIGGER_NUM:     267251196
GRB_RA:          359.590d {+23h 58m 22s} (J2000),
                 359.711d {+23h 58m 51s} (current),
                 358.956d {+23h 55m 49s} (1950)
GRB_DEC:         +60.260d {+60d 15' 36"} (J2000),
                 +60.313d {+60d 18' 46"} (current),
                 +59.982d {+59d 58' 54"} (1950)
GRB_ERROR:       8.08 [deg radius, statistical only]
DATA_SIGNIF:     9.50 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15994.49 SOD {04:26:34.49} UT
GRB_PHI:         182.00 [deg]
GRB_THETA:        17.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         69.90 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:       64.42d {+04h 17m 41s}  +25.56d {+25d 33' 23"}
MOON_DIST:        55.55 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      116.39, -1.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       34.59, 52.94 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:26:53 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      44
TRIGGER_NUM:     267251196
GRB_RA:           12.683d {+00h 50m 44s} (J2000),
                  12.816d {+00h 51m 16s} (current),
                  11.985d {+00h 47m 57s} (1950)
GRB_DEC:         +44.083d {+44d 04' 60"} (J2000),
                 +44.135d {+44d 08' 05"} (current),
                 +43.811d {+43d 48' 41"} (1950)
GRB_ERROR:       21.08 [deg radius, statistical plus systematic]
GRB_INTEN:       57 [cnts/sec]
DATA_SIGNIF:     5.60 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15003 TJD;   172 DOY;   09/06/21
GRB_TIME:        15994.49 SOD {04:26:34.49} UT
GRB_PHI:         240.00 [deg]
GRB_THETA:        20.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      1.62
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      70%  GRB
2nd_MOST_LIKELY:  18%  Solar Flare
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.93 [deg]   Sun_angle= 5.1 [hr] (West of Sun)
MOON_POSTN:       64.41d {+04h 17m 38s}  +25.56d {+25d 33' 19"}
MOON_DIST:        45.36 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.80,-18.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       31.02, 35.14 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 62.30,25.08 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:36:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 09"} (J2000)
ROLL:            87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16045.16 SOD {04:27:25.16} UT,   19.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     267251250
X_OFFSET:        779 [pixels]
Y_OFFSET:        894 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       939
Y_GRB_POS:       1054
BINNING_INDEX:   1
IM_URL:          sw00355303000msuni0024.fits
SUN_POSTN:        89.95d {+05h 59m 47s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.52d {+04h 18m 04s}  +25.57d {+25d 34' 01"}
MOON_DIST:        50.69 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:36:05 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 09"} (J2000)
ROLL:            87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16045.16 SOD {04:27:25.16} UT,   19.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     267251250
X_OFFSET:        779 [pixels]
Y_OFFSET:        894 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       939
Y_GRB_POS:       1054
BINNING_INDEX:   1
IM_URL:          sw00355303000msuni0024.fits
SUN_POSTN:        89.95d {+05h 59m 47s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.51d {+04h 18m 03s}  +25.57d {+25d 33' 59"}
MOON_DIST:        50.69 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [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 21 Jun 09 04:35:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 09"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16045.16 SOD {04:27:25.16} UT,   19.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.021
N_STARS:         190
X_OFFSET:        220 [pixels]
Y_OFFSET:        335 [pixels]
X_MAX:           1659 [pixels]
Y_MAX:           1774 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00355303000msufc0019.fits
SUN_POSTN:        89.95d {+05h 59m 47s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.51d {+04h 18m 01s}  +25.57d {+25d 33' 56"}
MOON_DIST:        50.68 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [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 21 Jun 09 04:34:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 09"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16045.16 SOD {04:27:25.16} UT,   19.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.021
N_STARS:         190
X_OFFSET:        220 [pixels]
Y_OFFSET:        335 [pixels]
X_MAX:           1659 [pixels]
Y_MAX:           1774 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00355303000msufc0019.fits
SUN_POSTN:        89.95d {+05h 59m 47s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.50d {+04h 18m 00s}  +25.56d {+25d 33' 53"}
MOON_DIST:        50.68 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:34:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 09"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16045.16 SOD {04:27:25.16} UT,   19.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.021
N_STARS:         190
X_OFFSET:        220 [pixels]
Y_OFFSET:        335 [pixels]
X_MAX:           1659 [pixels]
Y_MAX:           1774 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00355303000msufc0019.fits
SUN_POSTN:        89.95d {+05h 59m 47s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.50d {+04h 18m 00s}  +25.56d {+25d 33' 53"}
MOON_DIST:        50.68 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.05, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:29:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.997d {+00h 43m 59s} (J2000)
POINT_DEC:       +61.967d {+61d 58' 03"} (J2000)
ROLL:            87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  15885.76 SOD {04:24:45.76} UT,   86260.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     267251090
X_OFFSET:        779 [pixels]
Y_OFFSET:        894 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       939
Y_GRB_POS:       1054
BINNING_INDEX:   1
IM_URL:          sw00355303000msuni0127.fits
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.44d {+04h 17m 46s}  +25.56d {+25d 33' 32"}
MOON_DIST:        50.66 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:29:01 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.997d {+00h 43m 59s} (J2000)
POINT_DEC:       +61.967d {+61d 58' 03"} (J2000)
ROLL:            87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  15885.76 SOD {04:24:45.76} UT,   122.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     267251090
X_OFFSET:        779 [pixels]
Y_OFFSET:        894 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       939
Y_GRB_POS:       1054
BINNING_INDEX:   1
IM_URL:          sw00355303000msuni0127.fits
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.23 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.43d {+04h 17m 44s}  +25.56d {+25d 33' 28"}
MOON_DIST:        50.66 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [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 21 Jun 09 04:28:19 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.997d {+00h 43m 59s} (J2000)
POINT_DEC:       +61.967d {+61d 58' 03"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  15885.76 SOD {04:24:45.76} UT,   122.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.209
N_STARS:         79
X_OFFSET:        460 [pixels]
Y_OFFSET:        575 [pixels]
X_MAX:           1419 [pixels]
Y_MAX:           1534 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00355303000msufc0122.fits
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.22 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.43d {+04h 17m 42s}  +25.56d {+25d 33' 25"}
MOON_DIST:        50.65 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [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 21 Jun 09 04:27:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.997d {+00h 43m 59s} (J2000)
POINT_DEC:       +61.967d {+61d 58' 03"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  15885.76 SOD {04:24:45.76} UT,   122.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.209
N_STARS:         79
X_OFFSET:        460 [pixels]
Y_OFFSET:        575 [pixels]
X_MAX:           1419 [pixels]
Y_MAX:           1534 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00355303000msufc0122.fits
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.22 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.42d {+04h 17m 41s}  +25.56d {+25d 33' 23"}
MOON_DIST:        50.65 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:27:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.997d {+00h 43m 59s} (J2000)
POINT_DEC:       +61.967d {+61d 58' 03"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  15885.76 SOD {04:24:45.76} UT,   122.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.209
N_STARS:         79
X_OFFSET:        460 [pixels]
Y_OFFSET:        575 [pixels]
X_MAX:           1419 [pixels]
Y_MAX:           1534 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00355303000msufc0122.fits
SUN_POSTN:        89.94d {+05h 59m 46s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.22 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.42d {+04h 17m 41s}  +25.56d {+25d 33' 23"}
MOON_DIST:        50.65 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #9540
P.A. Curran (MSSL-UCL), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU), M. C. Stroh (PSU), T. N. Ukwatta (GSFC/GWU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 04:22:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090621 (trigger=355303). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 10.986, +61.968 which is
```
   RA(J2000) = 00h 43m 57s
   Dec(J2000) = +61d 58' 04"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed weak emission during the 8 seconds of the trigger interval. The peak count rate was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger.
There was a second BAT trigger (trigger=355304) at 04:27:05, about 4 minutes after the initial trigger from the same location. This portion of the BAT light curve is not immediately available from TDRSS, but the retrigger could indicate an extended prompt phase.
The XRT began observing the field at 04:24:40.46 UT, 117.3 seconds after the BAT trigger. XRT found an uncatalogued, variable X-ray source located at RA, Dec 11.0191, 61.9417 which is equivalent to:
```
   RA(J2000)  = 00h 44m 04.58s
   Dec(J2000) = +61d 56' 30.2"
```
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 110 arcseconds from the BAT onboard position, within the BAT error circle. There is a bright peak at about 250s after the initial trigger which could be X-ray emission during prolonged prompt emission.
UVOT took a finding chart exposure of 150 seconds with the White filter starting 122 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 25% of the BAT 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 BAT 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 P.A. Curran (pac AT mssl.ucl.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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:58:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 10"} (J2000)
ROLL:            87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16624.32 SOD {04:37:04.32} UT,   598.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     267251829
X_OFFSET:        779 [pixels]
Y_OFFSET:        894 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       939
Y_GRB_POS:       1054
BINNING_INDEX:   1
IM_URL:          sw00355303000msuni0603.fits
SUN_POSTN:        89.96d {+05h 59m 51s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.24 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.76d {+04h 19m 03s}  +25.59d {+25d 35' 36"}
MOON_DIST:        50.77 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:56:14 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 10"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16624.32 SOD {04:37:04.32} UT,   598.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.696
N_STARS:         190
X_OFFSET:        220 [pixels]
Y_OFFSET:        335 [pixels]
X_MAX:           1659 [pixels]
Y_MAX:           1774 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00355303000msufc0598.fits
SUN_POSTN:        89.96d {+05h 59m 51s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.24 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.74d {+04h 18m 58s}  +25.59d {+25d 35' 27"}
MOON_DIST:        50.77 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:56:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 10"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16624.32 SOD {04:37:04.32} UT,   598.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.696
N_STARS:         190
X_OFFSET:        220 [pixels]
Y_OFFSET:        335 [pixels]
X_MAX:           1659 [pixels]
Y_MAX:           1774 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00355303000msufc0598.fits
SUN_POSTN:        89.96d {+05h 59m 51s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.24 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.75d {+04h 19m 00s}  +25.59d {+25d 35' 30"}
MOON_DIST:        50.77 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [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 21 Jun 09 04:56:14 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 10"} (J2000)
POINT_ROLL:      87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16624.32 SOD {04:37:04.32} UT,   598.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.696
N_STARS:         190
X_OFFSET:        220 [pixels]
Y_OFFSET:        335 [pixels]
X_MAX:           1659 [pixels]
Y_MAX:           1774 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00355303000msufc0598.fits
SUN_POSTN:        89.96d {+05h 59m 51s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.24 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.74d {+04h 18m 58s}  +25.59d {+25d 35' 27"}
MOON_DIST:        50.77 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 21 Jun 09 04:58:01 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     355303,   Seg_Num: 0
POINT_RA:         10.993d {+00h 43m 58s} (J2000)
POINT_DEC:       +61.969d {+61d 58' 10"} (J2000)
ROLL:            87.993d
IMG_START_DATE:  15003 TJD;   172 DOY;   09/06/21
IMG_START_TIME:  16624.32 SOD {04:37:04.32} UT,   598.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     267251829
X_OFFSET:        779 [pixels]
Y_OFFSET:        894 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       939
Y_GRB_POS:       1054
BINNING_INDEX:   1
IM_URL:          sw00355303000msuni0603.fits
SUN_POSTN:        89.96d {+05h 59m 51s}  +23.44d {+23d 26' 15"}
SUN_DIST:         64.24 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:       64.76d {+04h 19m 03s}  +25.59d {+25d 35' 35"}
MOON_DIST:        50.77 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:      122.06, -0.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       43.21, 50.73 [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 Circular #9543
K.L. Page (U. Leicester) & P.A. Curran (UCL-MSSL) report on behalf of the Swift-XRT team:
We have analysed the first four orbits of XRT data obtained for GRB 090621 (Curran et al., GCN Circ. 9540), comprising 192 s of Windowed Timing (WT) mode and 6.4 ks of Photon Counting (PC) mode. The refined XRT position is RA, Dec = 11.01982, 61.94115, which is equivalent to
```
RA (J2000) =  00 44 04.76 
Dec(J2000) = +61 56 28.1
```
with an uncertainty of 3.6 arcsec (radius, 90% containment).
The X-ray light-curve shows a large increase in emission peaking at 264 s after the initial trigger, corresponding to the time of the second BAT trigger (Curran et al., GCN Circ. 9540). The underlying decay, however, can be parameterised as a single power-law with alpha = 0.81 +/- 0.04.
As is common, there is clear spectral evolution during the flare. A spectrum extracted from the PC mode data after the flare subsides (500 s after the trigger) can be modelled with a power-law of Gamma = 2.07 +0.37/-0.35 and a total absorbing column of (1.5 +/- 0.4)x10^22 cm^-2; the Galactic column in this direction is 5.6x10^21 cm^-2 (Kalberla et al. 2005). Using this spectrum, the counts to observed (unabsorbed) flux conversion factor is 6.3x10^-11 (1.5x10^-10) erg cm^-2 count^-1.
If the light-curve continues to decay with alpha ~ 0.81, the predicted count rate at 24 hours is 0.015 count s^-1, corresponding to an observed (unabsorbed) flux of 9.5x10^-13 (2.2x10^-12) erg cm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular #9544
P.A. Curran (UCL-MSSL) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090621 123 s after the BAT trigger (Curran et al., GCN 9540). No optical afterglow consistent with the refined XRT position (Page et al., GCN 9543) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first exposures are:
```
Filter         T_start(s)  T_stop(s)  Exp(s)     Mag

wh             123         7115       805        >21.5
v              613         6089       333        >19.4
b              538         6910       310        >20.5
u              282         6705       736        >20.5
uw1            662         6500       320        >19.8
um2            637         6295       333        >19.7
uw2            588         5884       333        >19.9
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #9546
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), P.A. Curran (MSSL-UCL), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090621A (trigger #355303) (Curran, et al., GCN Circ. 9540). The BAT ground-calculated position is RA, Dec = 10.987, 61.938 deg, which is
```
   RA(J2000)  =  00h 43m 56.8s 
   Dec(J2000) = +61d 56' 17.6" 
```
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%.
The mask-weighted light curve shows two small precursor peaks starting at ~T-30 sec, peaking at ~T-20 and T+10 sec, and returning to background at ~T+100 sec. Then the mmain emission starts at ~T+210 sec, peaks at ~T+240 and T+265 sec, and returns to background around T+350 sec. T90 is not possible because of a lack of the complete set of event by event data set for this burst. This also prevents giving spectral results.
GCN Circular #9555
E. Berger and W.-f. Fong (Harvard) report:
"We observed the field centered on the XRT error circle of the short GRB 090621 (GCNs #9545,9550) with the VLA at a frequency of 8.46 GHz starting on 2009 June 22.53 UT (14.6 hours post burst). We do not detect any sources within the refined XRT error circle to a 3-sigma limit of 54 microJy."
GCN Circular #9556
Arne Rau (MPE) reports on behalf of the Fermi GBM Team:
"At 04:26:34.49 UT on 21 June 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090621 (trigger 267251196 / 090621185) which was also detected by the Swift/BAT (Curan et al. 2009, GCN 9540). The GBM triggered on the second BAT trigger (355304) and at approx. 4 min after the initial BAT trigger (355303) for this event. The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 12 degrees.
The GBM light curve shows a faint peak coinciding with the initial Swift trigger (355303) and two brighter peaks starting at the GBM trigger time. The burst duration (T90) including the first faint peak is about 294 s (8-1000 keV).
The time-averaged spectrum of the two brighter peaks starting from the GBM trigger time T0-6.10 s to T0+45.06 s is best fit by a Band function with Epeak = 56.0 +/- 10.7 keV, alpha = -1.1 +/- 0.2, and beta = -2.12 +/- 0.09 (chi squared 377 for 366 d.o.f.).
The event fluence (8-1000 keV) in the above time interval is (4.4 +/- 1.0)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+35.840 s in the 8-1000 keV band is 1.92 +/- 0.06 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #9564
T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC), T. Okajima (JHU/GSFC), T.N. Ukwatta (GWU/GSFC), Y. Urata (NCU), C.A. Wallace (FGCU)
We observed the field of GRB 090621A detected by Swift (trigger #355303; Curran et al., GCN #9540) with the 14-inch Goddard Robotic Telescope (GRT) located at the Goddard Geophysical and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).
100 set of 30 sec exposures were taken in the R filter starting from June 21 05:00:15 (UT) about 37.3 min after the trigger and stopped on June 21 05:56:22 (UT). We do not detect the optical afterglow both in the individual images and the combined image inside the XRT position (Page et al., GCN #9543). The estimated three sigma upper limit of the combined image (total exposure of 2850 sec; excluding five bad quality images) is ~17.9 mag using the USNO-B1 catalog.
GCN Circular #9567
K.L. Page, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:
Using 5877 s of XRT Photon Counting mode data and 11 UVOT images, 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 = 11.02150, 61.94110 which is equivalent to:
```
RA (J2000):  00 44 5.16
Dec (J2000): +61 56 28.0
```
with an uncertainty of 1.4 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, arXiv:0812.3662).
This circular is an official product of the Swift-XRT team.
GCN Report 223.1
GCN_Report 223.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_223_1.pdf by P.A. Curran at MSSL-UCL titled: "Final Results on Swift GRB 090621A"
GCN Circular #9763
Carosi A. (INAF Rome), Gaug M. (IAC Tenerife), Antonelli L.A. (INAF Rome), Bastieri D. (Univ. Padova), Becerra Gonzalez J. (IAC Tenerife), Covino S. (INAF Rome), Galante N. (MPI Munich), Garczarczyk M. (IFAE Barcelona), La Barbera A. (INAF Palermo), Longo F. (INFN Trieste), Scapin V. (Univ. Udine) and Spiro S. (INAF Rome) for the MAGIC collaboration
The MAGIC Imaging Atmospheric Cherenkov Telescope performed a follow-up observation of the BAT burst GRB090621A (Curran et al., GCN Circ. 9540). The burst was also triggered by Fermi-GBM (Arne Rau, GCN Circ. 9556) We received the GCN alert at 04:23:38 UT (T0+55s). Data taking with MAGIC started at 04:36:18 UT (T0+815s), when the GRB zenith angle reached 46 degrees. The observation continued for 1833 s.
No evidence for VHE gamma-ray emission above the analysis threshold of 196 GeV was found. The observation was carried out in twilight condition.
A preliminary analysis, for the hypothesis of steady emission and assumption of a differential photon spectral index of -2.5, yields the following 95% CL differential flux upper limits, including a 30% systematic uncertainty on the telescope efficiency:
```
E(175 - 300  GeV): 0.25 * 10^-10 erg cm^-2 s^-1
E(300 - 1000 GeV): 0.10 * 10^-10 erg cm^-2 s^-1
for the whole time of observation (from 04:36:18 UT to 05:06:51 UT).
```
We can also exclude emission of a constant flux in any 100s time bin smaller than:
```
E(175 - 300  GeV):  2.74 * 10^-10 erg cm^-2 s^-1
E(300 - 1000 GeV):  1.01 * 10^-10 erg cm^-2 s^-1
for a time window from 04:36:18 UT to 05:06:51 UT
```
This message can be cited.
GCN Circular #10001
J. Haislip, D. Reichart, M. Maturi, K. Ivarsen, A. LaCluyze, A. Foster, J. Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M. Nysewander report:
Skynet observed the Swift/BAT localization of short-duration GRB 090621 (Curran et al., GCN 9545) with the 16" telescope at the Dolomiti Astronomical Observatory in Italy beginning 26.2 minutes after the trigger in Red, which we have calibrated to R.
We do not detect the afterglow (Curran et al., GCN 9545). Stacking only images that increase the limiting magnitude yields:
```
mean                                                 1-sig.  1-sig.
time                           3-sig.                sys.    stat.
since                          lim.    cal.          cal.    cal.
trig.  tel.    exp.      fil.  mag.    stars         unc.    unc.
(m)            (# x s)                               (mag)   (mag)

35.3   DAO-16  4 x 160   R     19.9    1518 USNO B1  0.277   0.000
                + 3 x 80
```

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Jochen Greiner, last update: 08-Oct-2009 [Disclaimer]