Gamma-ray Burst 091029

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:53:44 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     374210,   Seg_Num: 0
GRB_RA:           60.183d {+04h 00m 44s} (J2000),
                  60.239d {+04h 00m 57s} (current),
                  59.901d {+03h 59m 36s} (1950)
GRB_DEC:         -55.994d {-55d 59' 37"} (J2000),
                 -55.967d {-55d 57' 59"} (current),
                 -56.133d {-56d 07' 57"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4633 [cnts]    Image_Peak=243 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       27786 [cnts]
BKG_TIME:        13986.78 SOD {03:53:06.78} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15133 TJD;   302 DOY;   09/10/29
GRB_TIME:        14002.59 SOD {03:53:22.59} UT
GRB_PHI:         -148.43 [deg]
GRB_THETA:        16.98 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.00 [sigma]
IMAGE_SIGNIF:    9.18 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +0  +0  +0 +29  +0 
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 23"}
SUN_DIST:        107.05 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.34d {+22h 41m 22s}   -4.46d {-04d 27' 27"}
MOON_DIST:        80.66 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.88,-45.68 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       22.55,-72.48 [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 = 218.55,-15.03 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:55:07 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     374210,   Seg_Num: 0
GRB_RA:           60.1764d {+04h 00m 42.33s} (J2000),
                  60.2321d {+04h 00m 55.69s} (current),
                  59.8938d {+03h 59m 34.51s} (1950)
GRB_DEC:         -55.9553d {-55d 57' 19.0"} (J2000),
                 -55.9281d {-55d 55' 41.2"} (current),
                 -56.0944d {-56d 05' 39.6"} (1950)
GRB_ERROR:       5.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.80e-09 [erg/cm2/sec]
GRB_SIGNIF:      8.71 [sigma]
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14081.88 SOD {03:54:41.88} UT,   79.3 [sec] since BAT Trigger Time
TAM[0-3]:        327.70 237.23 261.52 243.61
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 25"}
SUN_DIST:        107.09 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.35d {+22h 41m 24s}   -4.45d {-04d 27' 09"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.83,-45.69 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.62,-72.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.32 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:55:21 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     374210,   Seg_Num: 0
GRB_RA:           60.1764d {+04h 00m 42.3s} (J2000),
                  60.2321d {+04h 00m 55.6s} (current),
                  59.8938d {+03h 59m 34.5s} (1950)
GRB_DEC:         -55.9553d {-55d 57' 19.0"} (J2000),
                 -55.9281d {-55d 55' 41.2"} (current),
                 -56.0944d {-56d 05' 39.6"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       76 [cnts]
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14081.88 SOD {03:54:41.88} UT,   79.3 [sec] since BAT Trigger Time
CENTROID_X:      341.74,  raw= 342  [pixels]
CENTROID_Y:      314.77,  raw= 315  [pixels]
ROLL:            152.86 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   39.55
GRB_POS_XRT_Z:   92.99
IMAGE_URL:       sw00374210000msxps_rw.img
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 25"}
SUN_DIST:        107.09 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.35d {+22h 41m 25s}   -4.45d {-04d 27' 06"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.83,-45.69 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.62,-72.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:55:17 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     374210,   Seg_Num: 0
GRB_RA:           60.1764d {+04h 00m 42.3s} (J2000),
                  60.2321d {+04h 00m 55.6s} (current),
                  59.8938d {+03h 59m 34.5s} (1950)
GRB_DEC:         -55.9553d {-55d 57' 19.0"} (J2000),
                 -55.9281d {-55d 55' 41.2"} (current),
                 -56.0944d {-56d 05' 39.6"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       76 [cnts]
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14081.88 SOD {03:54:41.88} UT,   79.3 [sec] since BAT Trigger Time
CENTROID_X:      341.74,  raw= 342  [pixels]
CENTROID_Y:      314.77,  raw= 315  [pixels]
ROLL:            152.86 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   39.55
GRB_POS_XRT_Z:   92.99
IMAGE_URL:       sw00374210000msxps_rw.img
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 25"}
SUN_DIST:        107.09 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.35d {+22h 41m 24s}   -4.45d {-04d 27' 07"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.83,-45.69 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.62,-72.44 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:57:18 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     374210,   Seg_Num: 0
GRB_RA:           60.183d {+04h 00m 44s} (J2000),
                  60.239d {+04h 00m 57s} (current),
                  59.901d {+03h 59m 36s} (1950)
GRB_DEC:         -55.994d {-55d 59' 37"} (J2000),
                 -55.967d {-55d 57' 59"} (current),
                 -56.133d {-56d 07' 57"} (1950)
GRB_DATE:        15133 TJD;   302 DOY;   09/10/29
GRB_TIME:        14002.59 SOD {03:53:22.59} UT
TRIGGER_INDEX:   146
GRB_PHI:         -148.43 [deg]
GRB_THETA:        16.98 [deg]
DELTA_TIME:      20.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.00 [sigma]
IMAGE_SIGNIF:    9.18 [sigma]
LC_URL:          sw00374210000msb.lc
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 26"}
SUN_DIST:        107.05 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.37d {+22h 41m 28s}   -4.44d {-04d 26' 40"}
MOON_DIST:        80.66 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.88,-45.68 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       22.55,-72.48 [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 = 218.55,-15.03 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:57:50 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.181d {+04h 00m 43s} (J2000)
POINT_DEC:       -55.984d {-55d 59' 00"} (J2000)
POINT_ROLL:      152.856d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14093.24 SOD {03:54:53.24} UT,   90.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.472
N_STARS:         46
X_OFFSET:        277 [pixels]
Y_OFFSET:        557 [pixels]
X_MAX:           1236 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00374210000msufc0090.fits
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 27"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.37d {+22h 41m 29s}   -4.44d {-04d 26' 33"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.57,-72.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:58:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.181d {+04h 00m 43s} (J2000)
POINT_DEC:       -55.984d {-55d 59' 00"} (J2000)
POINT_ROLL:      152.856d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14093.24 SOD {03:54:53.24} UT,   90.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.472
N_STARS:         46
X_OFFSET:        277 [pixels]
Y_OFFSET:        557 [pixels]
X_MAX:           1236 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00374210000msufc0090.fits
SUN_POSTN:       213.55d {+14h 14m 13s}  -13.47d {-13d 28' 27"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.38d {+22h 41m 30s}   -4.44d {-04d 26' 25"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.57,-72.47 [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:     Thu 29 Oct 09 03:59:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.181d {+04h 00m 43s} (J2000)
POINT_DEC:       -55.984d {-55d 59' 00"} (J2000)
ROLL:            152.856d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14093.24 SOD {03:54:53.24} UT,   90.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     278481298
X_OFFSET:        597 [pixels]
Y_OFFSET:        877 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       757
Y_GRB_POS:       1037
BINNING_INDEX:   1
IM_URL:          sw00374210000msuni0096.fits
SUN_POSTN:       213.55d {+14h 14m 13s}  -13.47d {-13d 28' 28"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.38d {+22h 41m 31s}   -4.44d {-04d 26' 16"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.57,-72.47 [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:     Thu 29 Oct 09 03:59:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.181d {+04h 00m 43s} (J2000)
POINT_DEC:       -55.984d {-55d 59' 00"} (J2000)
ROLL:            152.856d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14093.24 SOD {03:54:53.24} UT,   90.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     278481298
X_OFFSET:        597 [pixels]
Y_OFFSET:        877 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       757
Y_GRB_POS:       1037
BINNING_INDEX:   1
IM_URL:          sw00374210000msuni0096.fits
SUN_POSTN:       213.55d {+14h 14m 13s}  -13.47d {-13d 28' 28"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.38d {+22h 41m 32s}   -4.44d {-04d 26' 10"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.57,-72.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 03:57:50 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.181d {+04h 00m 43s} (J2000)
POINT_DEC:       -55.984d {-55d 59' 00"} (J2000)
POINT_ROLL:      152.856d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14093.24 SOD {03:54:53.24} UT,   90.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.472
N_STARS:         46
X_OFFSET:        277 [pixels]
Y_OFFSET:        557 [pixels]
X_MAX:           1236 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00374210000msufc0090.fits
SUN_POSTN:       213.55d {+14h 14m 12s}  -13.47d {-13d 28' 27"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.37d {+22h 41m 29s}   -4.44d {-04d 26' 33"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.57,-72.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:00:14 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     374210,   Seg_Num: 0
GRB_RA:           60.1777d {+04h 00m 42.64s} (J2000),
                  60.2334d {+04h 00m 56.00s} (current),
                  59.8951d {+03h 59m 34.82s} (1950)
GRB_DEC:         -55.9557d {-55d 57' 20.5"} (J2000),
                 -55.9285d {-55d 55' 42.6"} (current),
                 -56.0948d {-56d 05' 41.1"} (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:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14212.00 SOD {03:56:52.00} UT,   209.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       213.55d {+14h 14m 13s}  -13.47d {-13d 28' 29"}
SUN_DIST:        107.08 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.39d {+22h 41m 34s}   -4.43d {-04d 26' 01"}
MOON_DIST:        80.65 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.83,-45.69 [deg] galactic lon,lat of the burst
ECL_COORDS:       22.62,-72.45 [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.

GCN Circular #10097
D. Grupe (PSU), J. R. Cummings (NASA/UMBC), F. E. Marshall (NASA/GSFC), C. Pagani (PSU), D. M. Palmer (LANL), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 03:53:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 091029 (trigger=374210). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 60.183, -55.994 which is
```
   RA(J2000) = 04h 00m 44s
   Dec(J2000) = -55d 59' 37"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 50 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~18 sec after the trigger.
The XRT began observing the field at 03:54:41.9 UT, 79.3 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 60.17774, -55.95574 which is equivalent to:
```
   RA(J2000)  = 04h 00m 42.66s
   Dec(J2000) = -55d 57' 20.7"
```
with an uncertainty of 4.4 arcseconds (radius, 90% containment). This location is 138 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.14e+20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 1.80e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 90 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	04:00:42.58 = 60.17742
  DEC(J2000) = -55:57:20.0  = -55.95555
```
with a 90%-confidence error radius of about 0.70 arc sec. This position is 2.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 20.31 with a 1-sigma error of about 0.18. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02.
Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:05:54 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
POINT_ROLL:      152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14305.29 SOD {03:58:25.29} UT,   302.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.431
N_STARS:         28
X_OFFSET:        277 [pixels]
Y_OFFSET:        557 [pixels]
X_MAX:           1236 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00374210000msufc0302.fits
SUN_POSTN:       213.56d {+14h 14m 14s}  -13.48d {-13d 28' 34"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.43d {+22h 41m 44s}   -4.41d {-04d 24' 47"}
MOON_DIST:        80.64 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:06:29 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
POINT_ROLL:      152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14305.29 SOD {03:58:25.29} UT,   302.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.431
N_STARS:         28
X_OFFSET:        277 [pixels]
Y_OFFSET:        557 [pixels]
X_MAX:           1236 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00374210000msufc0302.fits
SUN_POSTN:       213.56d {+14h 14m 14s}  -13.48d {-13d 28' 34"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.44d {+22h 41m 45s}   -4.41d {-04d 24' 39"}
MOON_DIST:        80.64 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [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:     Thu 29 Oct 09 04:07:00 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
ROLL:            152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14305.29 SOD {03:58:25.29} UT,   302.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     278481510
X_OFFSET:        597 [pixels]
Y_OFFSET:        877 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       757
Y_GRB_POS:       1037
BINNING_INDEX:   1
IM_URL:          sw00374210000msuni0308.fits
SUN_POSTN:       213.56d {+14h 14m 14s}  -13.48d {-13d 28' 34"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.44d {+22h 41m 46s}   -4.41d {-04d 24' 32"}
MOON_DIST:        80.64 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [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:     Thu 29 Oct 09 04:05:54 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
POINT_ROLL:      152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14305.29 SOD {03:58:25.29} UT,   302.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.431
N_STARS:         28
X_OFFSET:        277 [pixels]
Y_OFFSET:        557 [pixels]
X_MAX:           1236 [pixels]
Y_MAX:           1516 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    2
SL_URL:          sw00374210000msufc0302.fits
SUN_POSTN:       213.56d {+14h 14m 14s}  -13.48d {-13d 28' 34"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.43d {+22h 41m 44s}   -4.41d {-04d 24' 47"}
MOON_DIST:        80.64 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:07:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
ROLL:            152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14305.29 SOD {03:58:25.29} UT,   302.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     278481510
X_OFFSET:        597 [pixels]
Y_OFFSET:        877 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       757
Y_GRB_POS:       1037
BINNING_INDEX:   1
IM_URL:          sw00374210000msuni0308.fits
SUN_POSTN:       213.56d {+14h 14m 14s}  -13.48d {-13d 28' 35"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.44d {+22h 41m 47s}   -4.41d {-04d 24' 28"}
MOON_DIST:        80.64 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:11:32 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
POINT_ROLL:      152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14860.94 SOD {04:07:40.94} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.493
N_STARS:         104
X_OFFSET:        37 [pixels]
Y_OFFSET:        317 [pixels]
X_MAX:           1476 [pixels]
Y_MAX:           1756 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00374210000msufc0858.fits
SUN_POSTN:       213.56d {+14h 14m 15s}  -13.48d {-13d 28' 38"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.48d {+22h 41m 54s}   -4.39d {-04d 23' 32"}
MOON_DIST:        80.63 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:11:59 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
POINT_ROLL:      152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14860.94 SOD {04:07:40.94} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.493
N_STARS:         104
X_OFFSET:        37 [pixels]
Y_OFFSET:        317 [pixels]
X_MAX:           1476 [pixels]
Y_MAX:           1756 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00374210000msufc0858.fits
SUN_POSTN:       213.56d {+14h 14m 15s}  -13.48d {-13d 28' 39"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.48d {+22h 41m 55s}   -4.39d {-04d 23' 26"}
MOON_DIST:        80.63 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [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:     Thu 29 Oct 09 04:11:32 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
POINT_ROLL:      152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14860.94 SOD {04:07:40.94} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.493
N_STARS:         104
X_OFFSET:        37 [pixels]
Y_OFFSET:        317 [pixels]
X_MAX:           1476 [pixels]
Y_MAX:           1756 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00374210000msufc0858.fits
SUN_POSTN:       213.56d {+14h 14m 15s}  -13.48d {-13d 28' 38"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.48d {+22h 41m 54s}   -4.39d {-04d 23' 32"}
MOON_DIST:        80.63 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 29 Oct 09 04:13:57 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
ROLL:            152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14860.94 SOD {04:07:40.94} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     278482066
X_OFFSET:        596 [pixels]
Y_OFFSET:        876 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       756
Y_GRB_POS:       1036
BINNING_INDEX:   1
IM_URL:          sw00374210000msuni0864.fits
SUN_POSTN:       213.56d {+14h 14m 15s}  -13.48d {-13d 28' 40"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.50d {+22h 41m 59s}   -4.38d {-04d 23' 00"}
MOON_DIST:        80.63 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [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:     Thu 29 Oct 09 04:14:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     374210,   Seg_Num: 0
POINT_RA:         60.175d {+04h 00m 42s} (J2000)
POINT_DEC:       -55.983d {-55d 58' 57"} (J2000)
ROLL:            152.861d
IMG_START_DATE:  15133 TJD;   302 DOY;   09/10/29
IMG_START_TIME:  14860.94 SOD {04:07:40.94} UT,   858.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     278482066
X_OFFSET:        596 [pixels]
Y_OFFSET:        876 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       756
Y_GRB_POS:       1036
BINNING_INDEX:   1
IM_URL:          sw00374210000msuni0864.fits
SUN_POSTN:       213.56d {+14h 14m 15s}  -13.48d {-13d 28' 41"}
SUN_DIST:        107.06 [deg]   Sun_angle= 10.2 [hr] (West of Sun)
MOON_POSTN:      340.50d {+22h 42m 00s}   -4.38d {-04d 22' 52"}
MOON_DIST:        80.63 [deg]
MOON_ILLUM:      78 [%]
GAL_COORDS:      266.87,-45.68 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       22.56,-72.46 [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 #10098
Robert Filgas (MPE Garching), Adria Updike (Clemson University), and Jochen Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 091029 (Swift trigger 374210; Grupe et al., GCN #10097) 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 at 03:57 UT on Oct 29, 4.5 min after the GRB trigger, and are continuing. They were performed at an average seeing of 1.6" and at an average airmass of 1.22.
We found a single point source within the 4.8 Swift-XRT error circle reported by Grupe et al. (GCN #10097) at
```
RA (J2000.0) = 04h 00m 42.7 s
DEC (J2000.0) = -55d 57' 19
```
with an uncertainty of 0.5".
Based on the first 5.3 min of total exposures in g'r'i'z' and 6.7 min in JHK, we estimate preliminary magnitudes (all in AB system) of
```
g' = 17.72 +- 0.1 mag,
r' = 17.45 +- 0.1 mag,
J = 17.00 +- 0.08 mag.
```
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #10099
A. LaCluyze, D. Reichart, K. Ivarsen, J. Haislip, R. Egger, 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 GRB 091029 (Grupe et al., GCN 10097) with three of the 16" PROMPT telescopes at CTIO beginning 46 seconds after the trigger in BRI through variable winds.
We detect the afterglow (Grupe et al., GCN 10097) in all filters.
The afterglow peaked in brightness approximately 5 - 6 minutes after the trigger, after which it has been fading with a power-law index of about -0.5.
GCN Circular #10100
R. Chornock, D. A. Perley, and B. E. Cobb (UC Berkeley) report on behalf of a larger collaboration:
We obtained optical spectra of the afterglow of GRB 091029 (Grupe et al., GCN 10097; Filgas et al., GCN 10098; LaCluyze et al., GCN 10099) using GMOS on Gemini-South. Our spectra cover the wavelength range of 3900-8100 angstroms with the R400 grating. Our first 600s exposure, starting at 06:06 UT on Oct. 29 (2.2 hr after the BAT trigger) reveals absorption lines from Lyman-alpha, C II, C IV, Si II, and Si IV at a common redshift of 2.752, which we identify as the redshift of the GRB. The afterglow is still quite bright (R~17.8 mag at t=2.02 hr) in the acquisition image.
We would like to thank German Gimeno and the Gemini staff for their assistance.
GCN Circular #10102
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 4524 s of XRT Photon Counting mode data and 7 UVOT images for GRB 091029, 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 = 60.17793, -55.95556 which is equivalent to:
```
RA (J2000): 04h 00m 42.70s
Dec (J2000): -55d 57' 20.0"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #10103
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), 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-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 091029 (trigger #374210) (Grupe, et al., GCN Circ. 10097). The BAT ground-calculated position is RA, Dec = 60.166, -55.954 deg, which is
```
   RA(J2000)  =  04h 00m 40.0s 
   Dec(J2000) = -55d 57' 12.7" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 99%.
The mask-weighted light curve shows three overlapping peaks, the first starting at ~T-10 sec, peaking at T+2, +20, and +26 sec, and ending at ~T+70 sec. T90 (15-350 keV) is 39.2 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T-1.8 to T+60.2 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.46 +- 0.27, and Epeak of 61.4 +- 17.5 keV (chi squared 49.9 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+19.12 sec in the 15-150 keV band is 1.8 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.88 +- 0.06 (chi squared 57.4 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/374210/BA/
GCN Circular #10104
A. de Ugarte Postigo (INAF-OAB), J. Gorosabel (IAA-CSIC), P. D'Avanzo (INAF-OAB), P. Kubanek (IPL UV, IAA-CSIC), M. Jelinek, R. Cunniffe, S. Guziy, A.J. Castro-Tirado (IAA-CSIC), P. Yock (Auckland Univ.), B.A. Allen (Vintage Lane Obs.), I. Bond (Massey Univ.), G. Christie (Stardome Obs.), report on behalf of a larger collaboration:
We have observed the afterglow of GRB 091029 (Grupe et al. GCN 10097) using the 0.6m Yock-Allen robotic telescope (BOOTES-3). A 24x60s combined unfiltered exposure with mid epoch October 29.450 UT (6.9 h after the burst) shows the afterglow at a magnitude of R = 18.5 +/- 0.2 as compared to USNO-B1 star n. 0340-0030266 (RA, Dec = 04:00:39.53, -55:56:55.17, R2 = 16.66).
A finding chart can be found at: http://www.brera.inaf.it/utenti/deugarte/GRB/091029/b3_091029.jpg
Further analysis is ongoing.
GCN Circular #10106
D. Grupe (PSU) reports on behalf of the Swift-XRT team:
We have analyzed the first 7 orbits of XRT data of GRB 091029 (Grupe et al. GCN Circ. 10097). The data comprise 69 s in Windowed Timing (WT) mode and 15727 s in Photon Counting (PC) mode. The enhanced XRT position has already been determined by Goad et al. (GCN circ. 10102).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.30+/-0.08 with an absorption column density consistent with the Galactic value of 1.14 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum (excluding the flare around 300 s after the burst) results in a slightly flatter X-ray spectrum with Gamma = 2.00+/-0.07.
The light curve (excluding the flares) can be modelled with a double broken power-law decay with an initial decay slope alpha-1 = 3.76+0.21-0.19 with the first break at 358+48-31 s after the trigger followed by a plateau phase with a decay slope alpha-2 = -0.17+/-0.22 and a second break at 3640+3450-1270 s. After this break the decay slope is alpha-3 = 0.76+0.06-0.05. If the afterglow continues to decay with a slope of 0.76, the predicted count rates 24, 48, and 72 hours after the trigger are
```
0.033 counts s^-1 or 1.12e-12 ergs s^-1 cm^-2,
0.020 counts s^-1 or 6.80e-13 ergs s^-1 cm^-2,
0.014 counts s^-1 or 4.76e-13 ergs s^-1 cm^-2, respectively.
```
This circular is an official product of the Swift-XRT team.
GCN Circular #10107
A. LaCluyze, D. Reichart, J. Haislip, K. Ivarsen, R. Egger, A. Foster, J. Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M. Nysewander report:
Skynet continued to observe the afterglow (Grupe et al., GCN 10097) of GRB 091029 (Grupe et al., GCN 10097) with three of the 16" PROMPT telescopes at CTIO in BRI.
After peaking in brightness 5 - 6 minutes after the trigger (LaCluyze et al., GCN 10099) the afterglow continued to fade as a power-law of index approximately -0.5 (LaCluyze et al., GCN 10099) until at least 4.7 hours after the trigger.
At 4.7 hours after the trigger, the afterglow's magnitude was I = 18.52 +/- 0.06 (statistical) +/- 0.41 (systematic; calibrated to 125 USNO B1 stars).
Skynet's most recent BRI light curve, calibrated to USNO B1 stars, can be found here:
http://skynet.unc.edu/grb/grb091029.png
GCN Circular #10108
F. E. Marshall (GSFC) and D. Grupe (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091029 91 sec. after the BAT trigger (Grupe et al., GCN Circ. 10097). We detect the optical afterglow at the refined UVOT position RA, Dec 60.17745, -55.95557, which is
```
     RA  (J2000)  04:00:42.59
     Dec (J2000) -55:57:20.0
```
with an estimated uncertainty of 0.55 arcsec (radius, 90% confidence). This position is consistent with the enhanced XRT position (Goad et al., GCN 10102). The detection in the white, v, b and u filters and not in the UV filters is consistent with the redshift of 2.752 (Chornock et al., GCN 10053).
The afterglow brightened by a factor of 4 between the first two observations in the white filter, which had mean observing times of T+166 s. and T+594s. The afterglow then decayed following an approximately power law form with a decay index of -0.45. This decay form lasted until at least T+8231 s. A similar optical light curve was reported by LaCluze et al. (GCN Circ. 10099 and 10107).
Preliminary magnitudes and 3 sigma upper limits are reported below.
```
Filter    T_start(s) T_stop(s)  Exposure(s)   Mag  Err
------------------------------------------------------------------------
white        91        240       147          20.22 +/- 0.13
white       584        603        19          18.75 +/- 0.14
v           635        654        19          17.81 +/- 0.26
b           559        578        19          19.04 +/- 0.28
u           303        552        19          18.42 +/- 0.08
uvw1        684       1280        58          > 19.32
uvm2       1930       1949        19          > 18.74
uvw2        611       1206        58          > 20.45
-------------------------------------------------------------------------
```
The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.02 mag (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383,627).
GCN Circular #10111
B. E. Cobb (UC Berkeley) reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 091029 (GCN 10097, Grupe et al.) with a mid-exposure time of 50 minutes post-burst (2009-10-29 04:43 UT). Total summed exposure times amounted to 36 minutes in I and 30 minutes in J. Imaging was done under poor (2.5") seeing conditions.
The afterglow of GRB 091029 (e.g. GCN 10097, Grupe et al.; GCN 10098, Filgas et al.; GCN 10099, LaCluyze et al.) is detected in our images. Preliminary comparison to USNO-B1.0 stars in I and 2MASS stars in J indicates the following afterglow magnitudes:
```
time post-burst         I mag           J mag
50 minutes              17.9+/-0.1      17.6+/-0.1
```
In individual I-band images, the afterglow fades by ~0.4 magnitudes between 30 and 69 minutes post-burst. During this time, the afterglow exhibits a shallow decay rate of alpha ~ -0.4+/-0.1 (where afterglow flux is proportional to t^alpha), which is consistent with the decay rate measured by LaCluyze et al. (GCN 10099).
GCN Circular #10137
G. W. Christie (Stardome Obs., New Zealand), S. Dong (IAS, Princeton), A. de Ugarte Postigo (INAF-OAB, Italy) and T. Natusch (Stardome Obs., New Zealand) report:
We observed the field of GRB 091029 (Swift trigger 372210, Grupe et al. GCN 10097) with the Stardome 0.4m telescope located in Auckland (New Zealand) starting at 07:55UT, 3.90 hours after BAT trigger. We used a SG530 filter that transmits wavelengths above 5300 Angstroms and a SBIG ST-L-6303E CCD (KAF-6303E detector).
A nearly continuous series of 300s images was taken until 16:30UT under mostly clear conditions (seeing: 1.6-2.5"). These were co-added making 15 stacks of 6 images (1800s exposure each).
The fading afterglow (Filgas et al., GCN 10098; LaCluyze et al., GCN 10099; de Ugarte Postigo et al., GCN 10104; Marshall et al. GCN 10108) was clearly detected in all images over the observing period, yielding the following psf photometry(DOPHOT):
```
UT (mid)    delT      R1      Err (statistical)
29.32713    3.901    19.34    0.09
29.34906    4.428    19.32    0.08
29.37120    4.959    19.43    0.08
29.39311    5.485    19.46    0.08
29.41503    6.011    19.67    0.08
29.43360    6.456    19.57    0.08
29.45862    7.057    19.73    0.08
29.50946    8.277    19.93    0.12
29.53164    8.809    19.94    0.09
29.56044    9.501    20.16    0.09
29.59390   10.304    20.21    0.11
29.61620   10.839    20.21    0.13
29.63853   11.375    20.36    0.16
29.66081   11.910    20.41    0.17
```
where delT is the mid-exposure time in hours since trigger. Photometric calibration was done against USNOB1 0340-0030262 RA (J2000.0): 04h 00m 38.61s, DEC( J2000.0): -55d 55' 37.3" assuming R1=16.40.
The mean power-law index over this interval was -0.94 (+/-0.05). Astrometry of the images gave the afterglow position (UCAC2) as:
```
RA (J2000.0) = 04h 00m 42.62s
DEC (J2000.0) = -55d 57' 20.2"
```
with an uncertainty of 0.18"
This position is in agreement with Marshall et al. (GCN 10108) and Grupe et al. (GCN 10097).
GCN Report 260.1
GCN_Report 260.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_260_1.pdf by D. Grupe at PSU titled: "Swift Observations on GRB 091029"
1605.01334 from 5 May 16
J. J. Geng et al.: Imprints of Electron-positron Winds on the Multi-wavelength Afterglows of Gamma-ray Bursts
Optical re-brightenings in the afterglows of some gamma-ray bursts (GRBs) are unexpected within the framework of the simple external shock model. While it has been suggested that the central engines of some GRBs are newly born magnetars, we aim to relate the behaviors of magnetars to the optical re-brightenings. A newly born magnetar will lose its rotational energy in the form of Poynting-flux, which may be converted into a wind of electron-positron pairs through some magnetic dissipation processes. As proposed by Dai (2004), this wind will catch up with the GRB outflow and a long-lasting reverse shock would form. By applying this scenario to GRB afterglows, we find that the reverse shock propagating back into the electron-positron wind can lead to an observable optical re-brightening and a simultaneous X-ray plateau (or X-ray shallow decay). In our study, we select four GRBs, i.e., GRB 080413B, GRB 090426, GRB 091029, and GRB 100814A, of which the optical afterglows are well observed and show clear re-brightenings. We find that they can be well interpreted. In our scenario, the spin-down timescale of the magnetar should be slightly smaller than the peak time of the re-brightening, which can provide a clue to the characteristics of the magnetar.

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Jochen Greiner, last update: 20-Apr-2024 [Disclaimer]