Gamma-ray Burst 051016

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:24:13 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     159913,   Seg_Num: 0
  GRB_RA:          122.811d {+08h 11m 15s} (J2000),
                   122.877d {+08h 11m 30s} (current),
                   122.248d {+08h 08m 60s} (1950)
  GRB_DEC:         -18.311d {-18d 18' 39"} (J2000),
                   -18.329d {-18d 19' 42"} (current),
                   -18.161d {-18d 09' 40"} (1950)
  GRB_ERROR:       4.00 [arcmin radius, statistical only]
  GRB_INTEN:       15871 [cnts]    Image_Peak=319 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   301     E_range: 25-100 keV
  BKG_INTEN:       141396 [cnts]
  BKG_TIME:        19352.00 SOD {05:22:32.00} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19411.35 SOD {05:23:31.35} UT
  GRB_PHI:           9.13 [deg]
  GRB_THETA:        49.30 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     12.44 [sigma]
  IMAGE_SIGNIF:    9.72 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +3  +2  +3  +0  +1 -23  +1 
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 20"}
  SUN_DIST:         76.23 [deg]
  MOON_POSTN:        5.60d {+00h 22m 23s}   +1.74d {+01d 44' 18"}
  MOON_DIST:       116.39 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.34 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      130.28,-37.27 [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.  
  

• red DSS finding chart ps-file
  
  
• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:26:03 UT
  NOTICE_TYPE:     Swift-XRT Image
  TRIGGER_NUM:     159913,   Seg_Num: 0
  GRB_RA:          122.8181d {+08h 11m 16.3s} (J2000),
                   122.8833d {+08h 11m 31.9s} (current),
                   122.2548d {+08h 09m 01.1s} (1950)
  GRB_DEC:         -18.2970d {-18d 17' 49.2"} (J2000),
                   -18.3145d {-18d 18' 52.1"} (current),
                   -18.1473d {-18d 08' 50.1"} (1950)
  GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
  GRB_INTEN:       22 [cnts]
  IMG_START_DATE:  13659 TJD;   289 DOY;   05/10/16
  IMG_START_TIME:  19523.50 SOD {05:25:23.50} UT
  CENTROID_X:      273.63,  raw= 274  [pixels]
  CENTROID_Y:      328.10,  raw= 328  [pixels]
  ROLL:            95.03 [deg]
  GAIN:            1
  MODE:            3, Long Image mode
  WAVEFORM:        134
  EXPO_TIME:       2.50 [sec]
  GRB_POS_XRT_Y:   66.38
  GRB_POS_XRT_Z:   -59.76
  IMAGE_URL:       sw00159913000msxim.img
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.22 [deg]
  MOON_POSTN:        5.61d {+00h 22m 27s}   +1.75d {+01d 44' 50"}
  MOON_DIST:       116.38 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.51,  8.35 [deg] galactic lon,lat of the burst
  ECL_COORDS:      130.28,-37.26 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Image.  
  COMMENTS:        WARNING: XRT alignment calibration is on-going, and there may be  
  COMMENTS:        residual systematic offsets of several arcseconds not accounted for yet  
  COMMENTS:        by our on-board position determination algorithm.  We have increased  
  COMMENTS:        the estimated error circle radius to take this into account.  
  

  
• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:26:03 UT
  NOTICE_TYPE:     Swift-XRT Position
  TRIGGER_NUM:     159913,   Seg_Num: 0
  GRB_RA:          122.8181d {+08h 11m 16.3s} (J2000),
                   122.8833d {+08h 11m 31.9s} (current),
                   122.2548d {+08h 09m 01.1s} (1950)
  GRB_DEC:         -18.2970d {-18d 17' 49.2"} (J2000),
                   -18.3145d {-18d 18' 52.1"} (current),
                   -18.1473d {-18d 08' 50.1"} (1950)
  GRB_ERROR:       5.8 [arcsec radius, statistical plus systematic, 90% containment]
  GRB_INTEN:       215.76 [arb]
  GRB_SIGNIF:      4.69 [sigma]
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19523.50 SOD {05:25:23.50} UT     [Start of CCD integration]
  TAM[0-3]:        327.64 237.21 261.19 243.29
  AMPLIFIER:       2
  WAVEFORM:        134
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.22 [deg]
  MOON_POSTN:        5.61d {+00h 22m 27s}   +1.75d {+01d 44' 50"}
  MOON_DIST:       116.38 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.51,  8.35 [deg] galactic lon,lat of the burst
  ECL_COORDS:      130.28,-37.26 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Coordinates.  
  COMMENTS:        WARNING: XRT alignment calibration is on-going, and there may be  
  COMMENTS:        residual systematic offsets of several arcseconds not accounted for yet  
  COMMENTS:        by our on-board position determination algorithm.  We have increased  
  COMMENTS:        the estimated error circle radius to take this into account.  
  

• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:27:05 UT
  NOTICE_TYPE:     Swift-XRT Processed Image
  TRIGGER_NUM:     159913,   Seg_Num: 0
  GRB_RA:          122.8181d {+08h 11m 16.3s} (J2000),
                   122.8833d {+08h 11m 31.9s} (current),
                   122.2548d {+08h 09m 01.1s} (1950)
  GRB_DEC:         -18.2970d {-18d 17' 49.2"} (J2000),
                   -18.3145d {-18d 18' 52.1"} (current),
                   -18.1473d {-18d 08' 50.1"} (1950)
  GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
  GRB_INTEN:       22 [cnts]
  IMG_START_DATE:  13659 TJD;   289 DOY;   05/10/16
  IMG_START_TIME:  19523.50 SOD {05:25:23.50} UT
  CENTROID_X:      273.63,  raw= 274  [pixels]
  CENTROID_Y:      328.10,  raw= 328  [pixels]
  ROLL:            95.03 [deg]
  GAIN:            1
  MODE:            3, Long Image mode
  WAVEFORM:        134
  EXPO_TIME:       2.50 [sec]
  GRB_POS_XRT_Y:   66.38
  GRB_POS_XRT_Z:   -59.76
  IMAGE_URL:       sw00159913000msxim.img
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.22 [deg]
  MOON_POSTN:        5.61d {+00h 22m 27s}   +1.75d {+01d 44' 50"}
  MOON_DIST:       116.38 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.51,  8.35 [deg] galactic lon,lat of the burst
  ECL_COORDS:      130.28,-37.26 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Processed Image.  
  

  
• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:27:24 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     159913,   Seg_Num: 0
  GRB_RA:          122.811d {+08h 11m 15s} (J2000),
                   122.877d {+08h 11m 30s} (current),
                   122.248d {+08h 08m 60s} (1950)
  GRB_DEC:         -18.311d {-18d 18' 39"} (J2000),
                   -18.329d {-18d 19' 42"} (current),
                   -18.161d {-18d 09' 40"} (1950)
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19411.35 SOD {05:23:31.35} UT
  TRIGGER_INDEX:   301
  GRB_PHI:           9.13 [deg]
  GRB_THETA:        49.30 [deg]
  DELTA_TIME:      6.00 [sec]
  TRIGGER_DUR:     4.096 [sec] 
  LC_URL:          sw00159913000msb.lc
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 20"}
  SUN_DIST:         76.23 [deg]
  MOON_POSTN:        5.60d {+00h 22m 23s}   +1.74d {+01d 44' 18"}
  MOON_DIST:       116.39 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.34 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      130.28,-37.27 [deg] ecliptic lon,lat of the pointing direction
  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.  
  

  
• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:29:23 UT
  NOTICE_TYPE:     Swift-XRT Lightcurve
  TRIGGER_NUM:     159913,   Seg_Num: 0
  POINT_RA:        122.799d {+08h 11m 12s} (J2000)
  POINT_DEC:       -18.314d {-18d 18' 49"} (J2000)
  LC_START_DATE:   13659 TJD;   289 DOY;   05/10/16
  LC_START_TIME:   19528.82 SOD {05:25:28.82} UT
  LC_STOP_DATE:    13659 TJD;   289 DOY;   05/10/16
  LC_STOP_TIME:    19750.66 SOD {05:29:10.66} UT
  LC_LIVE_TIME:    218.22 [sec], 98.4%
  DELTA_TIME:      86178.16 [sec]
  N_BINS:          100
  TERM_COND:       0
  LC_URL:          sw00159913000msx.lc
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.24 [deg]
  MOON_POSTN:        5.62d {+00h 22m 28s}   +1.75d {+01d 44' 51"}
  MOON_DIST:       116.36 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.33 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      130.26,-37.28 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-XRT Lightcurve.  
  

  
• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:30:16 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     159913,   Seg_Num: 0
  POINT_RA:        122.798d {+08h 11m 12s} (J2000)
  POINT_DEC:       -18.316d {-18d 18' 57"} (J2000)
  POINT_ROLL:      95.028d
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19527.00 SOD {05:25:27.00} UT
  FILTER:          3, V
  BKG_MEAN:        1.126
  N_STARS:         190
  X_OFFSET:        458 [pixels]
  Y_OFFSET:        444 [pixels]
  X_MAX:           1417 [pixels]
  Y_MAX:           1403 [pixels]
  DET_THRESH:      9
  PHOTO_THRESH:    4
  SL_URL:          sw00159913000msufc.fits
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.24 [deg]
  MOON_POSTN:        5.61d {+00h 22m 28s}   +1.75d {+01d 44' 51"}
  MOON_DIST:       116.36 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.33 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      130.26,-37.28 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:31:07 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     159913,   Seg_Num: 0
  POINT_RA:        122.798d {+08h 11m 12s} (J2000)
  POINT_DEC:       -18.316d {-18d 18' 57"} (J2000)
  POINT_ROLL:      95.028d
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19527.00 SOD {05:25:27.00} UT
  FILTER:          3, V
  BKG_MEAN:        1.126
  N_STARS:         190
  X_OFFSET:        458 [pixels]
  Y_OFFSET:        444 [pixels]
  X_MAX:           1417 [pixels]
  Y_MAX:           1403 [pixels]
  DET_THRESH:      9
  PHOTO_THRESH:    4
  SL_URL:          sw00159913000msufc.fits
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.24 [deg]
  MOON_POSTN:        5.61d {+00h 22m 28s}   +1.75d {+01d 44' 51"}
  MOON_DIST:       116.36 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.33 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      130.26,-37.28 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Source List.  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:32:06 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     159913,   Seg_Num: 0
  POINT_RA:        122.798d {+08h 11m 12s} (J2000)
  POINT_DEC:       -18.316d {-18d 18' 57"} (J2000)
  ROLL:            95.028d
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19527.00 SOD {05:25:27.00} UT
  FILTER:          3, V
  EXPOSURE_ID:     151133126
  X_OFFSET:        778 [pixels]
  Y_OFFSET:        764 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       938
  Y_GRB_POS:       924
  BINNING_INDEX:   1
  IM_URL:          sw00159913000msuni.fits
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.24 [deg]
  MOON_POSTN:        5.61d {+00h 22m 28s}   +1.75d {+01d 44' 51"}
  MOON_DIST:       116.36 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.33 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      130.26,-37.28 [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/SWIFT NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 16 Oct 05 05:32:35 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     159913,   Seg_Num: 0
  POINT_RA:        122.798d {+08h 11m 12s} (J2000)
  POINT_DEC:       -18.316d {-18d 18' 57"} (J2000)
  ROLL:            95.028d
  GRB_DATE:        13659 TJD;   289 DOY;   05/10/16
  GRB_TIME:        19527.00 SOD {05:25:27.00} UT
  FILTER:          3, V
  EXPOSURE_ID:     151133126
  X_OFFSET:        778 [pixels]
  Y_OFFSET:        764 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       938
  Y_GRB_POS:       924
  BINNING_INDEX:   1
  IM_URL:          sw00159913000msuni.fits
  SUN_POSTN:       201.23d {+13h 24m 56s}   -8.92d {-08d 55' 22"}
  SUN_DIST:         76.24 [deg]
  MOON_POSTN:        5.61d {+00h 22m 28s}   +1.75d {+01d 44' 51"}
  MOON_DIST:       116.36 [deg]
  MOON_ILLUM:      98 [%]
  GAL_COORDS:      238.52,  8.33 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      130.26,-37.28 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Image.  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN notice #4096
  P. Boyd (GSFC/UMBC), S. Barthelmy (GSFC), A. Beardmore (U. Leicester), D. Burrows (PSU), N. Gehrels (GSFC), C. Gronwall (PSU), S.T. Holland (GSFC), J. Kennea (PSU), C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC) on behalf of the Swift team:
  At 05:23:31 UT, Swift-BAT triggered and located GRB051016 (trigger=159913). The BAT on-board calculated location is RA,Dec 122.811,-18.311d {08h 11m 15s,-18d 18' 39"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve shows a single peak with a total duration of ~15 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~2 seconds after the trigger.
  The spacecraft slewed promptly and the XRT began observing the GRB at 05:25:23 UT, 112 sec after the BAT trigger. An uncatalogued source was found by the on-board centroiding algorithm at

   RA(J2000)= 08h 11m 16.3s
  DEC(J2000)=-18d 17' 49.2"
  

  with an uncertainty of 8 arcseconds radius (90% containment). This position lies 56 arcseconds from the centre of the BAT error circle. The initial flux is approximately 3.8E-10 ergs/cm2/s (0.3-10 keV). The count rate decreases during the first 100 seconds.
  UVOT began observing the field at 05:25:26 UT. The small image includes the BAT and the XRT error circles. This image contains no new sources down to a V limiting magnitude of 19.1 (3-sigma). No new source was seen in the list of sources from the entire UVOT field of view. E(B-V) in this direction is 0.088.
• GCN notice #4097
  M. Nysewander, D. Reichart, A. Crain, A. Foster, J. Haislip report on behalf of the UNC team of the FUN GRB Collaboration:
  Under the control of Skynet, PROMPT observed the localization of GRB 051016 (Boyd et al., GCN 4096) beginning 6.6 min after the burst, when the field was still at high airmass, in repeating blocks of BVRcIc (two filters simultaneously).
  We do not detect any new sources within or around the XRT localization. In a 12 x 80 sec integration of mean epoch 25.6 min after the burst, we measure a 3-sigma limiting magnitude of Rc = 19.1, based on 3 USNO-B1.0 stars.
  PROMPT is still being built and commissioned.
• GCN notice #4098
  E. Berger (Carnegie Observatories), M. Roth, and S. Gonzalez (Las Campanas Observatory) report:
  "We imaged the error circle of GRB 051016 (GCN #4096) with the Swope 40-inch telescope in I-band and with the Magellan telescope in J-band. A total of 10 min were obtained in I-band on Oct 16.345 UT and 20 min were obtained in J-band on Oct 16.325 UT (2.9 and 2.4 hours after the burst, respectively). We do not detect any sources within the XRT error circle which are not visible in the DSS. The 3-sigma upper limits are I>20 mag and J>21.7 mag."
• GCN notice #4099
  XMM-Newton will observe GRB051016 (GCN 4096) at location (RA=08h 11m 16.3s, DEC=-18d 17' 49.2", J2000), as triggered by D. Fox via XMM-Newton ToO alert, starting at 12:49 UT, on October 16, 2005, for an exposure of 30ksec seconds.
• GCN notice #4100
  A. Beardmore (U. Leicester), D. Burrows, J. Kennea (PSU), N. Gehrels (GSFC) report on behalf of the Swift XRT team:
  We have analysed the first two orbits of data from the Swift XRT observation of GRB051016 (Boyd et al., GCN4096). The refined ground processed coordinates are :

   RA(J2000)  =  08h 11m 16.3s
   Dec(J2000) = -18d 17m 56.3s
  

  with an estimated uncertainty of 8 arcsecs radius (90% containment). This is 7.1 arcsecs awsy from the XRT position reported in Boyd et al.
  The XRT light curve from this interval shows a steep initial decline, followed by a break to a shallower decay slope. A broken power-law fit to the light curve gives parameters :

  alpha_1 = 4.8 +0.5-0.4
  t_break = 247 +/- 15s
  alpha_2 = 0.7 +/- 0.1.
  

  The Windowed Timing (WT) and Photon Counting mode spectra from the first two orbits can be fit with an absorbed power-law with a photon index of 3.14+/-0.45 and a column density of 4.5+/-1.5 E21 cm-2, which is slightly in excess of the Galactic column density of 1.19E+21 cm-2 in this direction. The observed 0.2-10 keV flux for the WT data (exposure time 22.2s, centered at T+130s) was 1.31E-10 ergs cm**-2 s**-1, corresponding to an unabsorbed flux of 9.98E-10 ergs cm**-2 s**-1.
  Assuming the X-ray emission from the GRB continues to decline at the same rate, the predicted XRT count rate at T+24hrs is 0.0036 counts/s, which corresponds to an observed 0.2-10 keV flux of 1.1e-13 ergs cm**-2 s**-1.
• GCN notice #4101
  Nora Loiseau and Ricardo Perez-Martinez report:
  Quick-Look-Analysis of the XMM-Newton observation of the GRB051016 field based on an exposure in the EPIC pn camera that started at 13:46 UT, shows the presence of a source at the SWIFT/XRT position (Boyd et al., GCN4096) within XRT 8 arcsec radius uncertainty.
  The estimated EPIC/pn net count rate for the first 5.9 ksec is 0.029 counts/sec.
• GCN notice #4102
  J. Tueller (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cannizzo (GSFC-UMBC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Tashiro (Saitama U.), on behalf of the Swift-BAT team:
  Using the data set from T-300 to T+300 sec from recent telemetry downlinks, we report further analysis of Swift-BAT GRB 051016 (trigger 159913) (Boyd, et al., GCN 4096). The refined BAT ground position is (RA,Dec) = 122.820, -18.309 deg {8h 11m 16.9s, -18d 18' 33.2"} (J2000) +- 2.0 arcmin, (radius, sys+stat, 90% containment). This position is 38 arcsec from the refined XRT position (Beardmore t al., GCN 4100). The partial coding was 18 %.
  The light curve shows a FRED-like peak. T90 (15-350 keV) is (22 +- 1) sec (estimated error including systematics).
  The power law index of the time-averaged spectrum is 1.88 +- 0.27. The fluence in the 15-150 keV band is (8.8 +- 1.4) x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T0+0.3 sec in the 15-150 keV band is (1.6 +- 0.4) ph/cm2/sec. All the quoted errors are at the 90% confidence level.
• GCN notice #4109
  A. J. Blustin (UCL-MSSL), P. Boyd (GSFC), S. Oates (UCL-MSSL), R. Fink (GSFC), M. Ajello (MPE), N. Gehrels (GSFC) on behalf of the Swift/UVOT team report:
  The Swift-UVOT began taking settled exposures of the field of GRB 051016A 116 s after the BAT trigger (Boyd et al. GCN 4096). No new source with respect to the DSS is detected within the refined XRT error circle (Beardmore et al. GCN 4100) in summed images down to the following 3-sigma magnitude upper limits:

  Filter  T_range(sec)  Exp(sec)  3sigUL
  
  V       116-41900     3345      20.3
  B       483-40330     3693      21.7
  U       428-47088     2542      20.7
  W1      374-47026     3798      20.7
  M2      320-46119     3798      21.0
  W2      591-41238     3699      21.1
  

  Where T_range is time post-trigger.
• GCN Circular #4391
  Andrea De Luca (INAF/IASF, Milano) on behalf of a larger collaboration reports:
  We have analyzed the data from the XMM-Newton observation of GRB051016, discovered by Swift on 2005, October 16 at 05:23:31 UT (Boyd et al., GCN4096).
  The XMM-Newton observation started on 2005, October 16 at 13:44 UT and lasted for 29.4 ks.
  As reported by Loiseau and Perez-Martinez (GCN4101), the afterglow of GRB051016 is clearly detected in the EPIC images and its position is fully consistent with the refined Swift/XRT one (Morris et al., GCN3606).
  Extracting source events from a circle of 25 arcsec radius (containing ~80% of the total counts), the time-averaged, background-subtracted count rate in the 0.5-8 keV range is 0.028+/-0.001 cts/s, 0.0092+/-0.0006 cts/s and 0.0100+/-0.0006 cts/s in the pn, MOS1 and MOS2 cameras, respectively.
  The afterglow is seen to fade along the XMM-Newton observation, spanning the time range 30.0-59.4 ks after the GRB. The pn background-subtracted light curve (0.5-8 keV) is well fitted (reduced chi2=1.0, 7 d.o.f.) by a power law decay with index delta=0.9+/-0.3 (90% c.l.). The observed afterglow decay is consistent with the XRT results (Beardmore et al., GCN4100).
  We extracted the time-averaged spectra and generated ad-hoc response and effective area files for the pn, MOS1 and MOS2 cameras. The spectra were fitted simultaneously. Unless otherwise specified, we quote errors at 90% level for a single interesting parameter.
  A fit in the energy range 0.5-8 keV with an absorbed power law model yields an unacceptable reduced chi2 of 2.5 for 26 d.o.f., The resulting NH=(3.0+/-0.2)x10^21 cm^-2 is somewhat higher than the expected Galactic value in the burst direction (NH=1.1x10^21 cm^-2, Dickey & Lockman, 1990); the best fitting power law photon index is Gamma=2.6+/-0.3.
  A better fit may be obtained fixing the NH to the Galactic value and adding a redshifted neutral absorber. This yields a reduced chi2 of 1.74 for 25 d.o.f. The intrinsic gas column density and the redshift are not well constrained owing to their strong correlation. The best fit values are: intrinsic NH=6.7x10^22 cm^-2, z=4.1. At 90% confidence level for 2 parameters, the intrinsic NH is larger than 5x10^21 cm^-2 and the redshift is larger than 0.8. The best fit value of the power law photon index is Gamma=2.5+/-0.2. The observed flux (0.5-8 keV) is of 7.6x10^-14 erg cm^-2 s^-1, corresponding to an unabsorbed flux of 1.1x10^-13 erg cm^-2 s^-1.