Gamma-ray Burst 101023A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 23 Oct 10 22:50:20 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     309567006
GRB_RA:           15.467d {+01h 01m 52s} (J2000),
                  15.566d {+01h 02m 16s} (current),
                  15.005d {+01h 00m 01s} (1950)
GRB_DEC:         -67.667d {-67d 39' 59"} (J2000),
                 -67.609d {-67d 36' 30"} (current),
                 -67.935d {-67d 56' 06"} (1950)
GRB_ERROR:       22.35 [deg radius, statistical plus systematic]
GRB_INTEN:       114 [cnts/sec]
DATA_SIGNIF:     5.50 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:           9.00 [deg]
GRB_THETA:       145.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.54
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 05"}
SUN_DIST:        100.24 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:       36.87d {+02h 27m 29s}  +18.95d {+18d 57' 13"}
MOON_DIST:        87.97 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      301.41,-49.43 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      323.10,-62.74 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 214.12,-12.62 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 23 Oct 10 22:50:29 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      57
TRIGGER_NUM:     309567006
GRB_RA:          298.067d {+19h 52m 16s} (J2000),
                 298.323d {+19h 53m 18s} (current),
                 296.875d {+19h 47m 30s} (1950)
GRB_DEC:         -65.783d {-65d 46' 59"} (J2000),
                 -65.755d {-65d 45' 17"} (current),
                 -65.912d {-65d 54' 41"} (1950)
GRB_ERROR:       18.43 [deg radius, statistical plus systematic]
GRB_INTEN:       148 [cnts/sec]
DATA_SIGNIF:     8.20 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          28.98 [deg]
GRB_THETA:       120.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      1.48
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   1%  Generic SGR
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 05"}
SUN_DIST:         79.42 [deg]   Sun_angle= -6.0 [hr] (East of Sun)
MOON_POSTN:       36.87d {+02h 27m 29s}  +18.95d {+18d 57' 14"}
MOON_DIST:       110.73 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      330.36,-30.77 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      285.52,-43.85 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 214.12,-12.62 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 23 Oct 10 22:50:39 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      68
TRIGGER_NUM:     309567006
GRB_RA:          322.317d {+21h 29m 16s} (J2000),
                 322.529d {+21h 30m 07s} (current),
                 321.326d {+21h 25m 18s} (1950)
GRB_DEC:         -63.717d {-63d 42' 59"} (J2000),
                 -63.669d {-63d 40' 07"} (current),
                 -63.935d {-63d 56' 07"} (1950)
GRB_ERROR:       8.60 [deg radius, statistical plus systematic]
GRB_INTEN:       248 [cnts/sec]
DATA_SIGNIF:     18.20 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          33.00 [deg]
GRB_THETA:       130.00 [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:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 05"}
SUN_DIST:         89.87 [deg]   Sun_angle= -7.6 [hr] (East of Sun)
MOON_POSTN:       36.87d {+02h 27m 30s}  +18.95d {+18d 57' 15"}
MOON_DIST:       100.25 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      329.98,-41.25 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      300.08,-45.64 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 214.12,-12.62 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 23 Oct 10 22:50:46 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     309567006
GRB_RA:          347.550d {+23h 10m 12s} (J2000),
                 347.714d {+23h 10m 51s} (current),
                 346.787d {+23h 07m 09s} (1950)
GRB_DEC:         -62.990d {-62d 59' 23"} (J2000),
                 -62.931d {-62d 55' 51"} (current),
                 -63.261d {-63d 15' 40"} (1950)
GRB_ERROR:       20.36 [deg radius, statistical only]
DATA_SIGNIF:     6.70 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          29.00 [deg]
GRB_THETA:       141.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 05"}
SUN_DIST:         99.16 [deg]   Sun_angle= -9.3 [hr] (East of Sun)
MOON_POSTN:       36.88d {+02h 27m 30s}  +18.95d {+18d 57' 16"}
MOON_DIST:        90.45 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      320.70,-50.50 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      314.95,-51.12 [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:     Sat 23 Oct 10 22:50:51 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      67
TRIGGER_NUM:     309567006
GRB_RA:          303.810d {+20h 15m 14s} (J2000),
                 304.085d {+20h 16m 20s} (current),
                 302.529d {+20h 10m 07s} (1950)
GRB_DEC:         -69.920d {-69d 55' 11"} (J2000),
                 -69.886d {-69d 53' 10"} (current),
                 -70.072d {-70d 04' 19"} (1950)
GRB_ERROR:       5.87 [deg radius, statistical only]
DATA_SIGNIF:     18.50 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          25.00 [deg]
GRB_THETA:       123.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 05"}
SUN_DIST:         81.07 [deg]   Sun_angle= -6.4 [hr] (East of Sun)
MOON_POSTN:       36.88d {+02h 27m 30s}  +18.95d {+18d 57' 17"}
MOON_DIST:       108.71 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      325.28,-32.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      286.74,-48.44 [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:     Sat 23 Oct 10 22:51:26 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      87
TRIGGER_NUM:     309567006
GRB_RA:          354.433d {+23h 37m 44s} (J2000),
                 354.582d {+23h 38m 20s} (current),
                 353.742d {+23h 34m 58s} (1950)
GRB_DEC:         -60.450d {-60d 27' 00"} (J2000),
                 -60.390d {-60d 23' 23"} (current),
                 -60.727d {-60d 43' 36"} (1950)
GRB_ERROR:       4.68 [deg radius, statistical plus systematic]
GRB_INTEN:       1478 [cnts/sec]
DATA_SIGNIF:     29.10 [sigma]
INTEG_TIME:      0.512 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          35.00 [deg]
GRB_THETA:       145.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO:      0.88
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic Transient
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 06"}
SUN_DIST:        103.14 [deg]   Sun_angle= -9.8 [hr] (East of Sun)
MOON_POSTN:       36.88d {+02h 27m 31s}  +18.96d {+18d 57' 22"}
MOON_DIST:        86.38 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      318.46,-54.40 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      321.54,-51.18 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 214.12,-12.62 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 23 Oct 10 22:51:35 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      127
TRIGGER_NUM:     309567006
GRB_RA:          354.650d {+23h 38m 36s} (J2000),
                 354.798d {+23h 39m 12s} (current),
                 353.960d {+23h 35m 50s} (1950)
GRB_DEC:         -60.617d {-60d 36' 59"} (J2000),
                 -60.557d {-60d 33' 23"} (current),
                 -60.894d {-60d 53' 36"} (1950)
GRB_ERROR:       3.73 [deg radius, statistical plus systematic]
GRB_INTEN:       2153 [cnts/sec]
DATA_SIGNIF:     114.60 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          35.00 [deg]
GRB_THETA:       145.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.77
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   2%  Generic Transient
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 06"}
SUN_DIST:        103.07 [deg]   Sun_angle= -9.8 [hr] (East of Sun)
MOON_POSTN:       36.88d {+02h 27m 32s}  +18.96d {+18d 57' 23"}
MOON_DIST:        86.44 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      318.17,-54.30 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      321.50,-51.38 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 214.12,-12.62 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 23 Oct 10 22:51:51 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      89
TRIGGER_NUM:     309567006
GRB_RA:          359.500d {+23h 58m 00s} (J2000),
                 359.639d {+23h 58m 33s} (current),
                 358.851d {+23h 55m 24s} (1950)
GRB_DEC:         -63.750d {-63d 45' 00"} (J2000),
                 -63.690d {-63d 41' 22"} (current),
                 -64.028d {-64d 01' 41"} (1950)
GRB_ERROR:       1.15 [deg radius, statistical only]
DATA_SIGNIF:     63.10 [sigma]
DATA_INTERVAL:   1.024 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          28.00 [deg]
GRB_THETA:       145.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 06"}
SUN_DIST:        101.56 [deg]   Sun_angle= -10.1 [hr] (East of Sun)
MOON_POSTN:       36.88d {+02h 27m 32s}  +18.96d {+18d 57' 25"}
MOON_DIST:        87.56 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      312.57,-52.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      320.83,-55.22 [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:     Sat 23 Oct 10 22:51:58 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      126
TRIGGER_NUM:     309567006
GRB_RA:          320.490d {+21h 21m 58s} (J2000),
                 320.711d {+21h 22m 51s} (current),
                 319.461d {+21h 17m 51s} (1950)
GRB_DEC:         -65.170d {-65d 10' 11"} (J2000),
                 -65.123d {-65d 07' 24"} (current),
                 -65.383d {-65d 22' 59"} (1950)
GRB_ERROR:       1.46 [deg radius, statistical only]
DATA_SIGNIF:     130.80 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82204.73 SOD {22:50:04.73} UT
GRB_PHI:          35.00 [deg]
GRB_THETA:       129.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       208.31d {+13h 53m 15s}  -11.62d {-11d 37' 06"}
SUN_DIST:         88.53 [deg]   Sun_angle= -7.5 [hr] (East of Sun)
MOON_POSTN:       36.89d {+02h 27m 33s}  +18.96d {+18d 57' 26"}
MOON_DIST:       101.52 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.64,-39.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      298.13,-46.59 [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/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:05:34 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     436981,   Seg_Num: 0
GRB_RA:          317.954d {+21h 11m 49s} (J2000),
                 318.180d {+21h 12m 43s} (current),
                 316.900d {+21h 07m 36s} (1950)
GRB_DEC:         -65.394d {-65d 23' 37"} (J2000),
                 -65.349d {-65d 20' 55"} (current),
                 -65.599d {-65d 35' 55"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       6284 [cnts]    Image_Peak=186 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   148     E_range: 25-100 keV
BKG_INTEN:       40587 [cnts]
BKG_TIME:        82193.69 SOD {22:49:53.69} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82212.38 SOD {22:50:12.38} UT
GRB_PHI:         -113.03 [deg]
GRB_THETA:        41.16 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.67 [sigma]
IMAGE_SIGNIF:    8.54 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -1  +0  +0  -4  +0 
SUN_POSTN:       208.32d {+13h 53m 17s}  -11.62d {-11d 37' 18"}
SUN_DIST:         87.46 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.01d {+02h 28m 01s}  +18.99d {+18d 59' 21"}
MOON_DIST:       102.67 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.88,-38.88 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      296.60,-46.32 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
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 = 11.71,-7.88 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:06:09 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     436981,   Seg_Num: 0
GRB_RA:          317.9704d {+21h 11m 52.89s} (J2000),
                 318.1966d {+21h 12m 47.17s} (current),
                 316.9170d {+21h 07m 40.07s} (1950)
GRB_DEC:         -65.3859d {-65d 23' 09.2"} (J2000),
                 -65.3411d {-65d 20' 28.0"} (current),
                 -65.5910d {-65d 35' 27.5"} (1950)
GRB_ERROR:       5.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       3.89e-08 [erg/cm2/sec]
GRB_SIGNIF:      7.34 [sigma]
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82296.88 SOD {22:51:36.88} UT,   84.5 [sec] since BAT Trigger Time
TAM[0-3]:        327.68 237.21 261.50 243.61
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       208.32d {+13h 53m 17s}  -11.62d {-11d 37' 19"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.01d {+02h 28m 03s}  +18.99d {+18d 59' 26"}
MOON_DIST:       102.66 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.89,-38.88 [deg] galactic lon,lat of the burst
ECL_COORDS:      296.61,-46.32 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.62 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:06:29 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     436981,   Seg_Num: 0
GRB_RA:          317.9704d {+21h 11m 52.8s} (J2000),
                 318.1966d {+21h 12m 47.1s} (current),
                 316.9170d {+21h 07m 40.0s} (1950)
GRB_DEC:         -65.3859d {-65d 23' 09.2"} (J2000),
                 -65.3411d {-65d 20' 28.0"} (current),
                 -65.5910d {-65d 35' 27.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       54 [cnts]
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82296.88 SOD {22:51:36.88} UT,   84.5 [sec] since BAT Trigger Time
CENTROID_X:      292.07,  raw= 292  [pixels]
CENTROID_Y:      283.70,  raw= 284  [pixels]
ROLL:            247.39 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -33.70
GRB_POS_XRT_Z:   -24.09
IMAGE_URL:       sw00436981000msxps_rw.img
SUN_POSTN:       208.32d {+13h 53m 17s}  -11.62d {-11d 37' 19"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.01d {+02h 28m 03s}  +18.99d {+18d 59' 29"}
MOON_DIST:       102.66 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.89,-38.88 [deg] galactic lon,lat of the burst
ECL_COORDS:      296.61,-46.32 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:06:19 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     436981,   Seg_Num: 0
GRB_RA:          317.9704d {+21h 11m 52.8s} (J2000),
                 318.1966d {+21h 12m 47.1s} (current),
                 316.9170d {+21h 07m 40.0s} (1950)
GRB_DEC:         -65.3859d {-65d 23' 09.2"} (J2000),
                 -65.3411d {-65d 20' 28.0"} (current),
                 -65.5910d {-65d 35' 27.5"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       54 [cnts]
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82296.88 SOD {22:51:36.88} UT,   84.5 [sec] since BAT Trigger Time
CENTROID_X:      292.07,  raw= 292  [pixels]
CENTROID_Y:      283.70,  raw= 284  [pixels]
ROLL:            247.39 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -33.70
GRB_POS_XRT_Z:   -24.09
IMAGE_URL:       sw00436981000msxps_rw.img
SUN_POSTN:       208.32d {+13h 53m 17s}  -11.62d {-11d 37' 19"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.01d {+02h 28m 03s}  +18.99d {+18d 59' 28"}
MOON_DIST:       102.66 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.89,-38.88 [deg] galactic lon,lat of the burst
ECL_COORDS:      296.61,-46.32 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:07:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     436981,   Seg_Num: 0
POINT_RA:        317.988d {+21h 11m 57s} (J2000)
POINT_DEC:       -65.394d {-65d 23' 36"} (J2000)
POINT_ROLL:      247.397d
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82305.31 SOD {22:51:45.31} UT,   92.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.344
N_STARS:         57
X_OFFSET:        592 [pixels]
Y_OFFSET:        536 [pixels]
X_MAX:           1551 [pixels]
Y_MAX:           1495 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00436981000msufc0092.fits
SUN_POSTN:       208.32d {+13h 53m 18s}  -11.62d {-11d 37' 20"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.02d {+02h 28m 05s}  +18.99d {+18d 59' 37"}
MOON_DIST:       102.67 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.88,-38.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      296.62,-46.33 [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 23 Oct 10 23:06:58 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     436981,   Seg_Num: 0
POINT_RA:        317.988d {+21h 11m 57s} (J2000)
POINT_DEC:       -65.394d {-65d 23' 36"} (J2000)
POINT_ROLL:      247.397d
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82305.31 SOD {22:51:45.31} UT,   92.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.344
N_STARS:         57
X_OFFSET:        592 [pixels]
Y_OFFSET:        536 [pixels]
X_MAX:           1551 [pixels]
Y_MAX:           1495 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00436981000msufc0092.fits
SUN_POSTN:       208.32d {+13h 53m 17s}  -11.62d {-11d 37' 19"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.02d {+02h 28m 04s}  +18.99d {+18d 59' 33"}
MOON_DIST:       102.66 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.88,-38.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      296.62,-46.33 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:08:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     436981,   Seg_Num: 0
POINT_RA:        317.988d {+21h 11m 57s} (J2000)
POINT_DEC:       -65.394d {-65d 23' 36"} (J2000)
ROLL:            247.397d
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82305.31 SOD {22:51:45.31} UT,   92.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     309567111
X_OFFSET:        871 [pixels]
Y_OFFSET:        911 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1031
Y_GRB_POS:       1071
BINNING_INDEX:   1
IM_URL:          sw00436981000msuni0099.fits
SUN_POSTN:       208.32d {+13h 53m 18s}  -11.62d {-11d 37' 20"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.03d {+02h 28m 07s}  +19.00d {+18d 59' 43"}
MOON_DIST:       102.67 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.88,-38.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      296.62,-46.33 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:08:16 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     436981,   Seg_Num: 0
GRB_RA:          317.954d {+21h 11m 49s} (J2000),
                 318.180d {+21h 12m 43s} (current),
                 316.900d {+21h 07m 36s} (1950)
GRB_DEC:         -65.394d {-65d 23' 37"} (J2000),
                 -65.349d {-65d 20' 55"} (current),
                 -65.599d {-65d 35' 55"} (1950)
GRB_DATE:        15492 TJD;   296 DOY;   10/10/23
GRB_TIME:        82212.38 SOD {22:50:12.38} UT
TRIGGER_INDEX:   148
GRB_PHI:         -113.03 [deg]
GRB_THETA:        41.16 [deg]
DELTA_TIME:      52.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.67 [sigma]
IMAGE_SIGNIF:    8.54 [sigma]
LC_URL:          sw00436981000msb.lc
SUN_POSTN:       208.32d {+13h 53m 18s}  -11.62d {-11d 37' 20"}
SUN_DIST:         87.46 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.03d {+02h 28m 07s}  +19.00d {+18d 59' 44"}
MOON_DIST:       102.68 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.88,-38.88 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      296.60,-46.32 [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 = 11.71,-7.88 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 23 Oct 10 23:08:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     436981,   Seg_Num: 0
POINT_RA:        317.988d {+21h 11m 57s} (J2000)
POINT_DEC:       -65.394d {-65d 23' 36"} (J2000)
ROLL:            247.397d
IMG_START_DATE:  15492 TJD;   296 DOY;   10/10/23
IMG_START_TIME:  82305.31 SOD {22:51:45.31} UT,   92.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     309567111
X_OFFSET:        871 [pixels]
Y_OFFSET:        911 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1031
Y_GRB_POS:       1071
BINNING_INDEX:   1
IM_URL:          sw00436981000msuni0099.fits
SUN_POSTN:       208.32d {+13h 53m 18s}  -11.62d {-11d 37' 20"}
SUN_DIST:         87.47 [deg]   Sun_angle= -7.3 [hr] (East of Sun)
MOON_POSTN:       37.03d {+02h 28m 07s}  +19.00d {+18d 59' 45"}
MOON_DIST:       102.67 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      328.88,-38.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      296.62,-46.33 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #11363
C. J. Saxton (UCL-MSSL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), M. De Pasquale (UCL-MSSL), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), O. M. Littlejohns (U Leicester), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), S. R. Oates (UCL-MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (OSU/NASA/GSFC), R. L. C. Starling (U Leicester) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:
At 22:50:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 101023A (trigger=436981). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 317.954, -65.394 which is
```
    RA(J2000) = 21h 11m 49s
    Dec(J2000) = -65d 23' 37"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The lightcurve shows a small initial pulse at T+0 seconds with a large FRED pulse at about T+55 sec. The peak flux was 32000 counts/sec at T+55 sec.
The XRT began observing the field at 22:51:36.9 UT, 84.5 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 317.9704, -65.3859 which is equivalent to:
```
    RA(J2000)  = 21h 11m 52.89s
    Dec(J2000) = -65d 23' 09.2"
```
with an uncertainty of 5.3 arcseconds (radius, 90% containment). This location is 37 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
UVOT took a finding chart exposure of 100 seconds with the White filter starting 92 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 expected extinction corresponding to E(B-V) of 0.03. The XRT position lies 10.6" from a catalogued USNO object, photometry is difficult due to the bright halo of the 13th magnitude USNO star. More data is required to determine if a new source is present.
Burst Advocate for this burst is C. J. Saxton (cjs2@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 Circular #11364
P. D'Avanzo, D. Fugazza (INAF/Brera), E. Palazzi (INAF-IASFBo) on behalf of the REM team report:
The robotic 60-cm REM telescope located at La Silla (Chile) observed automatically the field of GRB 101023A (Saxton et al. GCN 11363) with the REMIR near-infrared camera in imaging mode.
Inspection of two set of H-band images, carried out 37 and 63 minutes post burst, respectively, does not reveal any afterglow candidate within the XRT error circle down to a 3sigma limiting magnitude of H~14.8 and H~15.5, respectively (calibrated against the 2MASS catalogue).
GCN Circular #11365
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 934 s of XRT Photon Counting mode data and 2 UVOT images for GRB 101023A, 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 = 317.96358, -65.38852 which is equivalent to:
```
RA (J2000): 21h 11m 51.26s
Dec (J2000): -65d 23' 18.7"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #11366
A.J.Levan (U. Warwick), D. Perley (U. Berkeley) and P. D'Avanzo (INAF-OAB) report for a larger collaboration:
"We observed the field of GRB 101023A (Saxton et al. GCN 11363) with GMOS on Gemini-South. We obtained a first epoch of observations in the r-band beginning at 24 October 00:38, approximately 1.8 hours post-burst. A second epoch was obtained at 01:26. In these two observations we identify a fading point source at a location of
```
RA(J2000) 21:11:51.24 
DEC(J2000) -65:23:15.84
```
We identify this as the afterglow of GRB 101023A. The afterglow fades by approximately 0.35 magnitudes between the two epochs of observation, and has r~20.5 in our first epoch (based on archival zeropoints). The afterglow position is ~2.8" from the refined XRT position of Osborne et al. (GCN 11365).
We thank the staff of Gemini, in particular Henry Lee, for their help with these observations."
GCN Circular #11367
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), C. J. Saxton (UCL-MSSL), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+542 sec from the recent telemetry downlink, we report further analysis of BAT GRB 101023A (trigger #436981) (Saxton, et al., GCN Circ. 11363). The BAT ground-calculated position is RA, Dec = 317.949, -65.389 deg, which is
```
   RA(J2000)  =  21h 11m 47.8s 
   Dec(J2000) = -65d 23' 20.1" 
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%.
The mask-weighted light curve shows a small peak starting at ~T-10 sec, peaking at T_zero. The main emission starts with about 3 overaping peaks peaking at ~T+54 and ~T+58 sec and ending at ~T+140 sec. T90 (15-350 keV) is 80.8 +- 2.2 sec (estimated error including systematics).
The time-averaged spectrum from T-11.0 to T+137.3 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.26 +- 0.15, and Epeak of 101.1 +- 18.9 keV (chi squared 45.1 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 2.7 +- 0.1 x 10^-5 erg/cm2 and the 1-sec peak flux measured from T+57.34 sec in the 15-150 keV band is 0.0 +- 0.0 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.67 +- 0.03 (chi squared 69.3 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/436981/BA/
GCN Circular #11368
K.L. Page (U. Leicester) and C. J. Saxton (UCL-MSSL) report on behalf of the Swift-XRT team:
We have analysed 961 s of XRT data for GRB 101023A (Saxton et al. GCN Circ. 11363), from 88 s to 6.0 ks after the BAT trigger. The data comprise 109 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 11365).
The light curve can be modelled with an initial power-law decay with an index of alpha=4.30 (+0.11, -0.13), followed by a break at T+174 s to an alpha of 1.22 (+0.03, -0.09).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.99 (+/-0.06). The best-fitting absorption column is 1.93 (+/-0.16) x 10^21 cm^-2, in excess of the Galactic value of 2.6 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.15 (+0.22, -0.21) and a best-fitting absorption column of 2.1 (+/-0.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (6.1 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 1.22, the count rate at T+24 hours will be 0.020 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.6 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00436981.
This circular is an official product of the Swift-XRT team.
GCN Circular #11369
M. Nardini, F. Olivares E., and J. Greiner (all MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 101023A (Swift trigger 436981; Saxton et al., GCN #11363) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP, 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile). Observations started on October 23 at 23:59 UT, 1.2 hours after the GRB trigger, and were performed at an average seeing of 1.4" and at an average airmass of 1.3.
We detect the afterglow reported by Levan et al. (GCN #11366) in all GROND bands. Co-added images of 24 min of integration time in g'r'i'z' and 20 min in JHK with midtime at 01:47 UT yield the following magnitudes in the AB system:
```
g' = 21.16 +/- 0.04,
r' = 20.50 +/- 0.02,
i' = 20.00 +/- 0.02,
z' = 19.59 +/- 0.02,
J = 19.08 +/- 0.04,
H = 18.76 +/- 0.06, and
K = 17.64 +/- 0.06,
```
calibrated against GROND zeropoints and 2MASS field stars. We notice that the K-band magnitude might be contaminated by the near bright star. Between Oct 24 at 00:03 UT and Oct 24 at 1:47 UT the afterglow faded of ~0.75 mag in 1.75h.
No corrections for the expected Galactic foreground extinction were made, which corresponds to a reddening of E(B-V)=0.033 mag in the direction of the burst (Schlegel et al. 1998). Observations are continuing.
GCN Circular #11371
M. De Pasquale, C. Saxton and S. Oates (UCL-MSSL) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 101023A 93 s after the BAT trigger (Saxton et al, GCN Circ. 11363) with a 100s finding chart in the white filter. UVOT detected a fading optical source, with a position consistent with the enhanced XRT position (Osborne et al, GCN Circ. 11365), in the white filter exposures and, very marginally, in the first u band exposure. We identify this object as the optical afterglow of GRB101023A. There is no detection of this source in other filters, either in single or summed up exposures.
The position of this optical afterglow is
```
RA =21h 11m 51.26s (317.96360)
Dec = -65d 23m 15.7s (-65.38769) (J2000)
```
with an estimated uncertainty of 0.6 arcsec. This position is consistent with the source identified by Gemini (Levan et al, GCN Circ. 11366) and GROND Nardini et al., GCN 11369). We caution that the photometry of this object is rather complicated by the presence of a bright star 13rd magnitude star, which is located about 15 arcseconds from the optical afterglow.
Preliminary magnitudes and 3-sigma upper limits using the UVOT photometric system (Poole et al, 2008, MNRAS, 383, 627) for the initial exposures are:
```
Filter      T_start(s)  T_stop(s)   Exp(s)        Mag

white (fc)      93        193        100     19.4 +/- 0.2
white         5895      10094        960     21.7 +/- 0.4 (2.8 sigma)
v             3524      15873       1082         >20.2
b             4344       4483        137         >20.2
u             4139       4339        200     20.5 +/- 0.6 (2 sigma)
u            21640      22548        882         >21.1
w1            3934      21633       1126         >21.1
m2            3728      16778       1082         >21.2
w2           10101      10653        544         >21.0
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #11376
Michael S. Briggs (UAHuntsville) reports on behalf of the Fermi GBM Team:
"At 22:50:04.73 UT on 23 October 2010, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 101023A (trigger 309567006 / 101023.951).
The burst was also detected by the SWIFT-BAT (C. J. Saxton et al. 2010, GCN 11363). The GBM on-ground location is consistent with the Swift position.
The GBM light curve shows two major pulses, the first from 0 to 25 s relative to the trigger time, the second from 45 to 100 seconds, with the GRB having a T90 duration of 77 +/- 8 s (50-300 keV). The spectrum from 0 to 95 s is well fit with a cutoff power law with an index of -1.64 +/- 0.01 and an Epeak of 277 +/- 14 keV. The fluence (10-1000 keV) for the t90 time interval is (6.4 +/- 0.1) E-05 erg/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #11377
C. J. Saxton (UCL-MSSL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), M. De Pasquale (UCL-MSSL), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), O. M. Littlejohns (U Leicester), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), S. R. Oates (UCL-MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL), M. Stamatikos (OSU/NASA/GSFC), R. L. C. Starling (U Leicester) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:
At 22:50:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 101023A (trigger=436981). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 317.954, -65.394 which is
```
   RA(J2000) = 21h 11m 49s
   Dec(J2000) = -65d 23' 37"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The lightcurve shows a small initial pulse at T+0 seconds with a large FRED pulse at about T+55 sec. The peak flux was 32000 counts/sec at T+55 sec.
The XRT began observing the field at 22:51:36.9 UT, 84.5 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 317.9704, -65.3859 which is equivalent to:
```
   RA(J2000)  = 21h 11m 52.89s
   Dec(J2000) = -65d 23' 09.2"
```
with an uncertainty of 5.3 arcseconds (radius, 90% containment). This location is 37 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
UVOT took a finding chart exposure of 100 seconds with the White filter starting 92 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 expected extinction corresponding to E(B-V) of 0.03. The XRT position lies 10.6" from a catalogued USNO object, photometry is difficult due to the bright halo of the 13th magnitude USNO star. More data is required to determine if a new source is present.
Burst Advocate for this burst is C. J. Saxton (cjs2@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 Circular #11379
K. Motohara, T. Tanabe, S. Koshida, T. Morokuma, T. Minezaki, and Y. Yoshii (University of Tokyo), report on behalf of the TAO project team:
We observed GRB 101023A (Saxton et al., GCN 11363) with the near-infrared camera ANIR mounted on the miniTAO 1.0m telescope at the University of Tokyo Atacama Observatory on the summit of Co. Chajnantor (5640m altitude) in the northern Chile.
The J-, H-, and Ks-band observations started from 2010-10-24 02:48 UT (3hours after the burst), and total exposure time was 540sec for each band. The afterglow was detected in all the three bands at the position reported by Levan et al. (GCN 11366). The seeing was 0.9-1.0arcsec throughout the observations, and the image of the afterglow was clearly separated from the nearby bright star.
AB magnitudes are are listed below, where the flux calibrations were carried out using 2MASS stars within the FoV.
```
Band   Mid-UT    AB-Mag
----------------------------
Ks      02:53:05  19.40 +/- 0.10
H       03:07:41  20.28 +/- 0.27
J       03:24:36  19.92 +/- 0.14
----------------------------
```
GCN Circular #11384
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report:
The long GRB 101023A, (Swift/BAT trigger=3D436981: Saxton, et al., GCN 11363; Stamatikos et.al, GCN 11367) triggered Konus-Wind at T0=3D82264.703s UT (22:51:04.703)
The burst light curve started, at ~T0-65s, with a weak initial pulse, followed by a much brighter and harder emission episode, peaked at ~T0+5s. The total duration of the burst is ~100 s. The emission is seen up to 2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB101023_T82264/
As observed by Konus-Wind the burst had a fluence of (6.6 =B1 0.5)x10-5 erg/cm2, and a 256-ms peak flux, measured from T0+4.096s, of (7.1 =B1 0.5)x10-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range).
The time-integrated spectrum of major part of the burst (from T0 to T0+29.952 s) is best fit in the 20 keV - 2 MeV range by the GRB (Band) model, for which: the low-energy photon index alpha =3D -1.07 (-0.07, +0.08), the high energy photon index beta =3D -2.5 (-0.3, +0.7), the peak energy Ep =3D 200(-16, +17) keV (chi2 =3D 73/57 dof).
The spectrum at the maximum count rate (measured from T0+0.256 to T0+6.400 s) is best fit in the 20 keV - 2 MeV range by the GRB (Band) model, for which: the low-energy photon index alpha =3D -0.84 (-0.07, +0.08), the high energy photon index beta =3D -2.8 (-0.4, +0.2), the peak energy Ep =3D 239(-17, +18) keV (chi2 =3D 56/57 dof).
All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.
GCN Report 308.1
GCN_Report 308.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_308_1.pdf by C.J. Curtis at MSSL/UCL titled: "Final report on Swift Observations of GRB 101023A"
GCN Circular #11459
R. Ruffini, L. Izzo, A. Penacchione, S.K. Chakrabarti on behalf of ICRAnet reports:
We have tentatively identified the redshift factor z of GRB 101023A (GCN 11363, 11364, 11365, 11366) to be between 0.7 to 1.0 from Amati relation. This GRB had two major pulses whose E_iso appear to be ~10^52 ergs and ~2x10^53 ergs respectively. Despite being bright and nearby, no Supernovae has been reported for this source. We encourage anyone having data especially around 1st to 7th of November, 2010, on this object on supernovae association (either way) to report them to facilitate understanding this object.
GCN Circular #11460
R. Ruffini, L. Izzo, A. Penacchione, S.K. Chakrabarti on behalf of ICRAnet reports:
We have tentatively identified the redshift factor z of GRB 101023A (GCN 11363, 11364, 11365, 11366) to be between 0.7 to 1.0 from Amati relation. This GRB had two major pulses whose E_iso appear to be ~1052 ergs and ~2x1053 ergs respectively. Despite being bright and nearby, no Supernovae has been reported for this source. We encourage anyone having data especially around 1st to 7th of November, 2010, on this object on supernovae association (either way) to report them to facilitate understanding this object.

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Jochen Greiner, last update: 24-Oct-2010 [Disclaimer]