Gamma-ray Burst 100316A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 16 Mar 10 02:23:28 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     416076,   Seg_Num: 0
  GRB_RA:          252.032d {+16h 48m 08s} (J2000),
                   251.998d {+16h 47m 59s} (current),
                   252.200d {+16h 48m 48s} (1950)
  GRB_DEC:         +71.825d {+71d 49' 31"} (J2000),
                   +71.808d {+71d 48' 28"} (current),
                   +71.911d {+71d 54' 39"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       10057 [cnts]    Image_Peak=203 [image_cnts]
  TRIGGER_DUR:     2.048 [sec] 
  TRIGGER_INDEX:   268     E_range: 25-100 keV
  BKG_INTEN:       102464 [cnts]
  BKG_TIME:        8546.38 SOD {02:22:26.38} UT
  BKG_DUR:         24 [sec]
  GRB_DATE:        15271 TJD;    75 DOY;   10/03/16
  GRB_TIME:        8580.43 SOD {02:23:00.43} UT
  GRB_PHI:         144.10 [deg]
  GRB_THETA:        43.96 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     13.71 [sigma]
  IMAGE_SIGNIF:    8.09 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +1  +2  -2  +0  +0 +10  +0 
  SUN_POSTN:       355.77d {+23h 43m 05s}   -1.83d {-01d 49' 53"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.23d {+23h 44m 56s}   +3.46d {+03d 27' 48"}
  MOON_DIST:        91.10 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.81, 35.13 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      132.31, 81.78 [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 = 111.06,-3.02 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 16 Mar 10 02:26:33 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     416076,   Seg_Num: 0
  GRB_RA:          252.032d {+16h 48m 08s} (J2000),
                   251.998d {+16h 47m 59s} (current),
                   252.200d {+16h 48m 48s} (1950)
  GRB_DEC:         +71.825d {+71d 49' 31"} (J2000),
                   +71.808d {+71d 48' 28"} (current),
                   +71.911d {+71d 54' 39"} (1950)
  GRB_DATE:        15271 TJD;    75 DOY;   10/03/16
  GRB_TIME:        8580.43 SOD {02:23:00.43} UT
  TRIGGER_INDEX:   268
  GRB_PHI:         144.10 [deg]
  GRB_THETA:        43.96 [deg]
  DELTA_TIME:      -44.00 [sec]
  TRIGGER_DUR:     2.048 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     13.71 [sigma]
  IMAGE_SIGNIF:    8.09 [sigma]
  LC_URL:          sw00416076000msb.lc
  SUN_POSTN:       355.77d {+23h 43m 05s}   -1.83d {-01d 49' 50"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.26d {+23h 45m 02s}   +3.47d {+03d 28' 28"}
  MOON_DIST:        91.10 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.81, 35.13 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      132.31, 81.78 [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 = 111.06,-3.02 [deg].  
  

  
• GCN Circular #10484
  W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), E. Troja (NASA/GSFC/ORAU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
  At 02:23:00 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100316A trigger=416076). The BAT on-board calculated location is RA, Dec 252.032, +71.825 which is

     RA(J2000) = 16h 48m 08s
     Dec(J2000) = +71d 49' 31"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 10 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~2 sec after the trigger.
  Due to an observing constraint, Swift will not slew until T0+51.8 minutes. There will be no XRT or UVOT data until this time.
  Burst Advocate for this burst is W. H. Baumgartner (wayne AT milkyway.gsfc.nasa.gov). 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:     Tue 16 Mar 10 03:16:24 UT
  NOTICE_TYPE:     Swift-XRT Nack-Position
  TRIGGER_NUM:     416076,   Seg_Num: 0
  POINT_RA:        251.996d {+16h 47m 59s} (J2000)
  POINT_DEC:       +71.823d {+71d 49' 21"} (J2000)
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11777.50 SOD {03:16:17.50} UT,   3197.1 [sec] since BAT Trigger Time
  COUNTS:          1    Min_needed= 20
  STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
  PH2_ITER:        0    Max_iter_allowed= 4
  ERROR_CODE:      1
  COMMENTS:        SWIFT-XRT Nack Position.  
  COMMENTS:        No source found in the image.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 16 Mar 10 03:19:23 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     416076,   Seg_Num: 0
  POINT_RA:        251.996d {+16h 47m 59s} (J2000)
  POINT_DEC:       +71.823d {+71d 49' 22"} (J2000)
  POINT_ROLL:      77.406d
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11781.04 SOD {03:16:21.04} UT,   3200.6 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        1.450
  N_STARS:         55
  X_OFFSET:        564 [pixels]
  Y_OFFSET:        522 [pixels]
  X_MAX:           1523 [pixels]
  Y_MAX:           1481 [pixels]
  DET_THRESH:      10
  PHOTO_THRESH:    5
  SL_URL:          sw00416076000msufc3200.fits
  SUN_POSTN:       355.80d {+23h 43m 13s}   -1.82d {-01d 48' 58"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.66d {+23h 46m 39s}   +3.67d {+03d 39' 58"}
  MOON_DIST:        91.05 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.82, 35.15 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      132.36, 81.77 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 16 Mar 10 03:19:23 UT
  NOTICE_TYPE:     Swift-UVOT Source List
  TRIGGER_NUM:     416076,   Seg_Num: 0
  POINT_RA:        251.996d {+16h 47m 59s} (J2000)
  POINT_DEC:       +71.823d {+71d 49' 22"} (J2000)
  POINT_ROLL:      77.406d
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11781.04 SOD {03:16:21.04} UT,   3200.6 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        1.450
  N_STARS:         55
  X_OFFSET:        564 [pixels]
  Y_OFFSET:        522 [pixels]
  X_MAX:           1523 [pixels]
  Y_MAX:           1481 [pixels]
  DET_THRESH:      10
  PHOTO_THRESH:    5
  SL_URL:          sw00416076000msufc3200.fits
  SUN_POSTN:       355.80d {+23h 43m 13s}   -1.82d {-01d 48' 58"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.66d {+23h 46m 39s}   +3.67d {+03d 39' 58"}
  MOON_DIST:        91.05 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.82, 35.15 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      132.36, 81.77 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Source List.  
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 16 Mar 10 03:19:54 UT
  NOTICE_TYPE:     Swift-UVOT Processed Source List
  TRIGGER_NUM:     416076,   Seg_Num: 0
  POINT_RA:        251.996d {+16h 47m 59s} (J2000)
  POINT_DEC:       +71.823d {+71d 49' 22"} (J2000)
  POINT_ROLL:      77.406d
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11781.04 SOD {03:16:21.04} UT,   3200.6 [sec] since BAT Trigger Time
  FILTER:          10, White
  BKG_MEAN:        1.450
  N_STARS:         55
  X_OFFSET:        564 [pixels]
  Y_OFFSET:        522 [pixels]
  X_MAX:           1523 [pixels]
  Y_MAX:           1481 [pixels]
  DET_THRESH:      10
  PHOTO_THRESH:    5
  SL_URL:          sw00416076000msufc3200.fits
  SUN_POSTN:       355.80d {+23h 43m 13s}   -1.82d {-01d 48' 57"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.67d {+23h 46m 40s}   +3.67d {+03d 40' 05"}
  MOON_DIST:        91.05 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.82, 35.15 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      132.36, 81.77 [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:     Tue 16 Mar 10 03:20:32 UT
  NOTICE_TYPE:     Swift-UVOT Image
  TRIGGER_NUM:     416076,   Seg_Num: 0
  POINT_RA:        251.996d {+16h 47m 59s} (J2000)
  POINT_DEC:       +71.823d {+71d 49' 22"} (J2000)
  ROLL:            77.406d
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11781.04 SOD {03:16:21.04} UT,   3200.6 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     290402186
  X_OFFSET:        883 [pixels]
  Y_OFFSET:        841 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       1043
  Y_GRB_POS:       1001
  BINNING_INDEX:   1
  IM_URL:          sw00416076000msuni3206.fits
  SUN_POSTN:       355.81d {+23h 43m 13s}   -1.82d {-01d 48' 57"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.67d {+23h 46m 41s}   +3.67d {+03d 40' 13"}
  MOON_DIST:        91.05 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.82, 35.15 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      132.36, 81.77 [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:     Tue 16 Mar 10 03:20:59 UT
  NOTICE_TYPE:     Swift-UVOT Processed Image
  TRIGGER_NUM:     416076,   Seg_Num: 0
  POINT_RA:        251.996d {+16h 47m 59s} (J2000)
  POINT_DEC:       +71.823d {+71d 49' 22"} (J2000)
  ROLL:            77.406d
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11781.04 SOD {03:16:21.04} UT,   3200.6 [sec] since BAT Trigger Time
  FILTER:          10, White
  EXPOSURE_ID:     290402186
  X_OFFSET:        883 [pixels]
  Y_OFFSET:        841 [pixels]
  WIDTH:           160 [pixels]
  HEIGHT:          160 [pixels]
  X_GRB_POS:       1043
  Y_GRB_POS:       1001
  BINNING_INDEX:   1
  IM_URL:          sw00416076000msuni3206.fits
  SUN_POSTN:       355.81d {+23h 43m 13s}   -1.82d {-01d 48' 56"}
  SUN_DIST:         96.01 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.67d {+23h 46m 42s}   +3.67d {+03d 40' 19"}
  MOON_DIST:        91.05 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.82, 35.15 [deg] galactic lon,lat of the pointing direction
  ECL_COORDS:      132.36, 81.77 [deg] ecliptic lon,lat of the pointing direction
  COMMENTS:        SWIFT-UVOT Processed Image.  
  COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
  COMMENTS:        The image has 2x2 binning (compression).  
  COMMENTS:        All 4 attachments are included.  
  

  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Tue 16 Mar 10 03:55:57 UT
  NOTICE_TYPE:     Swift-XRT Position
  TRIGGER_NUM:     416076,   Seg_Num: 0
  GRB_RA:          251.9789d {+16h 47m 54.93s} (J2000),
                   251.9452d {+16h 47m 46.84s} (current),
                   252.1473d {+16h 48m 35.34s} (1950)
  GRB_DEC:         +71.8264d {+71d 49' 35.0"} (J2000),
                   +71.8088d {+71d 48' 31.7"} (current),
                   +71.9121d {+71d 54' 43.7"} (1950)
  GRB_ERROR:       4.5 [arcsec radius, statistical plus systematic, 90% containment]
  GRB_INTEN:       1.00e-10 [erg/cm2/sec]
  GRB_SIGNIF:      10.00 [sigma]
  IMG_START_DATE:  15271 TJD;    75 DOY;   10/03/16
  IMG_START_TIME:  11796.00 SOD {03:16:36.00} UT,   3215.6 [sec] since BAT Trigger Time
  TAM[0-3]:        100.00 100.00 100.00 100.00
  AMPLIFIER:       1
  WAVEFORM:        31
  SUN_POSTN:       355.83d {+23h 43m 19s}   -1.81d {-01d 48' 22"}
  SUN_DIST:         96.02 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:      356.94d {+23h 47m 46s}   +3.80d {+03d 47' 55"}
  MOON_DIST:        91.01 [deg]
  MOON_ILLUM:      0 [%]
  GAL_COORDS:      103.82, 35.15 [deg] galactic lon,lat of the burst
  ECL_COORDS:      132.36, 81.77 [deg] ecliptic lon,lat of the burst
  COMMENTS:        SWIFT-XRT Coordinates.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        TAM values, flux and significance fields are not valid.  
  COMMENTS:        This position was automatically generated on the ground using  
  COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
  COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
  COMMENTS:        The probability that this is a serendipitous source in the  
  COMMENTS:        SPER window is 15% < P(seren) < 100%.  
  

• GCN Circular #10485
  A.P. Beardmore, K.L. Page and O. Littlejohns (U. Leicester) report on behalf on the Swift-XRT team:
  Using 2.4ks of promptly downlinked data starting at 51.8 minutes after the trigger we find an uncatalogued X-ray source located at RA, Dec = 251.9789, 71.8265 which is equivalent to:

  RA  (J2000.0) =  16 47 54.94
  DEC (J2000.0) =  +71 49 35.3
  

  with an uncertainty of 4.53 arcsec (radius, 90% containment).
  It is not possible to tell whether the source is fading with the limited data available so far.
• GCN Circular #10486
  M. H. Siegel (PSU) and W. H. Baumgartner (GSFC/UMBC) report on behalf of the Swift/UVOT team:
  UVOT took a finding chart exposure of 150 seconds with the White filter starting 3200 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 (Beardmore et al., GCN Circ. 10485). 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.
• GCN Circular #10487
  J. Gorosabel (IAA-CSIC), V. Peris (U. Valencia), P. Kubanek (IAA-CSIC, U. Valencia), report on behalf of a larger collaboration:
  "We have carried out R-band observations of the GRB100316 BAT error box (Baumgartner et al., GCN 10484) with the 1.23m telescope of Calar Alto. The observations started on Feb 16.1075 UT (11.7 min after the GRB). We detect an object with a rough magnitude of R~20.5 coincident with the XRT (GCN 10485) position and very likely not present on the DSS. Further observations are encouraged to determine the possible fading behaviour of this source. We propose that object as the potential optical afterglow of GRB100316."
• GCN Circular #10488
  J. Gorosabel (IAA-CSIC), V. Peris (U. Valencia), P. Kubanek (IAA-CSIC, U. Valencia), report on behalf of a larger collaboration:
  "We have carried out R-band observations of the GRB100316 BAT error box (Baumgartner et al., GCN 10484) with the 1.23m telescope of Calar Alto. The observations started on Feb 16.1075 UT (11.7 min after the GRB). We detect an object with a rough magnitude of R~20.5 coincident with the XRT (GCN 10485) position and very likely not present on the DSS. Further observations are encouraged to determine the possible fading behaviour of this source. We propose that object as the potential optical afterglow of GRB100316."
• GCN Circular #10490
  P.A. Evans reports on behalf of the Swift-XRT team
  Using 1129 s of XRT Photon Counting mode data and 2 UVOT images, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 251.98150, 71.82780 which is equivalent to:

  RA (J2000):  16 47 55.56
  Dec (J2000): +71 49 40.0
  

  with an uncertainty of 2.9 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 is an official product of the Swift-XRT team.
• GCN Circular #10499
  S. R. Oates (MSSL-UCL) and W. H. Baumgartner (GSFC/UMBC) report on behalf of the Swift/UVOT team:
  The Swift/UVOT began settled observations of the field of GRB 100316A 3201s after the BAT trigger (Baumgartner et al., GCN Circ. 10484). We do not detect any source at the enhanced Swift XRT position (Evans et al. GCN Circ. 10490) and at the location of the candidate source detected by the CAHA telescope (Gorosabel et al. GCN Circ. 10487).
  The 3-sigma upper limits for the finding chart exposures (FC) and summed images are:

  Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
  -------------------------------------------------------------
  white (FC) 3201     3350     147     > 21.08
  white      3770     5408     393     > 21.32
  v          4182     16726    1210    > 20.48
  b          3565     5203     393     > 20.79
  u          3359     11527    1110    > 20.66
  uvw1       4593     10786    1082    > 21.11
  uvm2       4387     17306    1648    > 21.11
  uvw2       3977     15812    1279    > 21.28
  -------------------------------------------------------------
  

  The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.03 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).
• GCN Circular #10501
  W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
  Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100316A (trigger #416076) (Baumgartner, et al., GCN Circ. 10484). The BAT ground-calculated position is RA, Dec = 251.953, 71.819 deg which is

     RA(J2000)  =  16h 47m 48.8s 
     Dec(J2000) = +71d 49' 09.5" 
  

  with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 16%.
  The mask-weighted light curve shows a FRED-like pulse starting at ~T-1 sec, peaking at ~t+2 sec, and ending at ~T+20 sec. T90 (15-350 keV) is 7.0 +- 0.9 sec (estimated error including systematics).
  The time-averaged spectrum from T-1.2 to T+6.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.46 +- 0.18. The fluence in the 15-150 keV band is 8.2 +- 0.9 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+1.94 sec in the 15-150 keV band is 2.3 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
  The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/416076/BA/
• GCN Circular #10503
  A. P. Beardmore (U. Leicester) and W. H. Baumgartner (GSFC/UMBC) report on behalf of the Swift-XRT team:
  Due to an Earth-limb constraint, Swift performed a delayed slew to GRB 100316A (Baumgartner et al. GCN Circ. 10484), with XRT observations starting 3.2 ks after the BAT trigger. The enhanced XRT position for this burst was given by Evans (GCN. Circ 10490).
  The X-ray light curve, obtained from 7.5 ks of Photon Counting (PC) mode data spanning 3.2 ks to 17.3 ks after the trigger, can be modelled by a power-law decay, with a decay slope of 1.3 +/- 0.3.
  An X-ray spectrum formed from the same data can be modelled by an absorbed power-law, with a photon index of 2.3 +0.3 -0.5 and absorbing column density of (1.5 +1.2 -1.1) x 10^21 cm^-2, which is in excess of the Galactic value of 4.4 x 10^20 cm^-2 (Kalberla et al. 2005) in the direction of the source. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1.
  If the light curve continues to decay at the same rate, the count rate at T+24 hours will be 1.2 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.0 x 10^-14 (6.3 x 10^-14) erg cm^-2 s^-1.
  The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00416076.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #10504
  Gendre B. (ASDC), Klotz A. (CESR-OMP), Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:
  We imaged the field of GRB 100316A detected by SWIFT (trigger 416076, GCN 10484, Baumgartner et al. ) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
  The observations started 1323s after the GRB trigger (1299s after the notice). The elevation of the field increased from 58 degrees above horizon and weather conditions were good.
  We obtained 16 image with clear filter and 8 images with R filter (see the description in Klotz et al., 2006, A&A 451, L39).
  We do not detect any OT within the exposures. Co-adding the images taken with clear filter, we can set a limiting magnitude of:
  R > 20.0 between t0+1323s to t0+3327s
  at the position of the candidate reported by Gorosabel et al. (GCN 10487) and Beardmore et al. (GCN 10485).
  Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
  N.B. Galactic coordinates are lon=103.8139 lat=+35.1341 and the galactic extinction in R band is 0.1 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
  This message may be cited.
• GCN Circular #10521
  V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
  We observed the field of the Swift GRB 100316A (Baumgartner et al. GCN 10484) with Shajn telescope of CrAO starting (UT) March 16 19:15 under descending weather conditions and mean seeing of 2 arcsec. No object is detected in enhanced XRT error circle (Evans, GCN 10490).
  The upper limit of point like object in a stacked image based on USNO-B1.0 star 1618-0120609 (J2000) RA= 16:48:06.44 Dec= +71:50:15.2 (assuming R2=15.25) is following:

  T0+      Filter,   Exposure, mag.
  (mid, d)              (s)
  
  0.7061   R       8x60    > 21.6
  

  The non-detection is strongly support the object of R~20.5 reported in GCN 10487 (Gorosabel et al) is the optical afterglow of GRB100316A.
• GCN Circular #10565
  Jang, M., Im, M. (SNU), and Y. Urata (NCU) report on behalf of the EAFON collaboration:
  We observed GRB100316A in R-band starting at 2010 March16, 08:09:17UT, or 20.78 ks after the BAT triggered (Baumgartner et al, GCN 10484), using the 1.0m telescope at Mt.Lemmon in Arizona, U.S. operated by Korea Astronomy Space Science Institute.
  No afterglow candidate was detected from a stacked image of eight 300s-frames. within the error circle of the enhanced XRT position (Evans et al.,GCN 10490). We estimate the 3-sigma limiting magnitude of the afterglow to be R ~ 22.0 +/- 0.2 at the midpoint time of the stacked image (~T0+21.98 ks) by calibrating it against sixteen USNO-B1 stars near the GRB, using their R2 magnitudes without correcting for the Galactic extinction.
  Our limit indicates fading of the optical afterglow candidate reported by Gorosabel et al. (GCN 10488) shortly after.
  We thank the LOAO operator, I. Baek for her help with the observation
• Redshift of z = 3.155
  Highlights of Spanish Astrophysics VII, pp.463-463 RMxAC 42 (2013) 113