Gamma-ray Burst 100904A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sat 04 Sep 10 01:34:16 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     433273,   Seg_Num: 0
  GRB_RA:          172.919d {+11h 31m 41s} (J2000),
                   173.053d {+11h 32m 13s} (current),
                   172.289d {+11h 29m 09s} (1950)
  GRB_DEC:         -16.209d {-16d 12' 31"} (J2000),
                   -16.268d {-16d 16' 03"} (current),
                   -15.933d {-15d 55' 57"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       9882 [cnts]    Image_Peak=241 [image_cnts]
  TRIGGER_DUR:     2.048 [sec] 
  TRIGGER_INDEX:   255     E_range: 15-50 keV
  BKG_INTEN:       104020 [cnts]
  BKG_TIME:        5585.85 SOD {01:33:05.85} UT
  BKG_DUR:         24 [sec]
  GRB_DATE:        15443 TJD;   247 DOY;   10/09/04
  GRB_TIME:        5623.80 SOD {01:33:43.80} UT
  GRB_PHI:         -111.92 [deg]
  GRB_THETA:        35.22 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     12.24 [sigma]
  IMAGE_SIGNIF:    8.27 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +1  +1  -1 -100  +0 -90  +0 
  SUN_POSTN:       162.87d {+10h 51m 28s}   +7.28d {+07d 16' 37"}
  SUN_DIST:         25.61 [deg]   Sun_angle= -0.7 [hr] (East of Sun)
  MOON_POSTN:      101.64d {+06h 46m 33s}  +22.80d {+22d 47' 52"}
  MOON_DIST:        80.01 [deg]
  MOON_ILLUM:      26 [%]
  GAL_COORDS:      276.54, 42.54 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      180.15,-17.65 [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 = 204.29,-0.04 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sat 04 Sep 10 01:37:27 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     433273,   Seg_Num: 0
  GRB_RA:          172.919d {+11h 31m 41s} (J2000),
                   173.053d {+11h 32m 13s} (current),
                   172.289d {+11h 29m 09s} (1950)
  GRB_DEC:         -16.209d {-16d 12' 31"} (J2000),
                   -16.268d {-16d 16' 03"} (current),
                   -15.933d {-15d 55' 57"} (1950)
  GRB_DATE:        15443 TJD;   247 DOY;   10/09/04
  GRB_TIME:        5623.80 SOD {01:33:43.80} UT
  TRIGGER_INDEX:   255
  GRB_PHI:         -111.92 [deg]
  GRB_THETA:        35.22 [deg]
  DELTA_TIME:      45.00 [sec]
  TRIGGER_DUR:     2.048 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     12.24 [sigma]
  IMAGE_SIGNIF:    8.27 [sigma]
  LC_URL:          sw00433273000msb.lc
  SUN_POSTN:       162.87d {+10h 51m 29s}   +7.28d {+07d 16' 34"}
  SUN_DIST:         25.61 [deg]   Sun_angle= -0.7 [hr] (East of Sun)
  MOON_POSTN:      101.67d {+06h 46m 41s}  +22.79d {+22d 47' 33"}
  MOON_DIST:        79.98 [deg]
  MOON_ILLUM:      26 [%]
  GAL_COORDS:      276.54, 42.54 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      180.15,-17.65 [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 = 204.29,-0.04 [deg].  
  

  
• GCN Circular #11203
  T. N. Ukwatta (GSFC/GWU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Rowlinson (U Leicester), M. H. Siegel (PSU) and C. A. Swenson (PSU) report on behalf of the Swift Team:
  At 01:33:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100904A (trigger=433273). Due to the Sun constraint, Swift could not slew to the burst. The BAT on-board calculated location is RA, Dec 172.919, -16.209 which is

     RA(J2000) = 11h 31m 41s
     Dec(J2000) = -16d 12' 31"
  

  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 30 sec. The peak count rate was ~1300 counts/sec (15-350 keV), during the second peak at ~2 sec after the trigger.
  Due to the proximity of the burst to the Sun, Swift cannot slew to the BAT position. The burst does not become observable by Swift until November 7th; there will thus be no XRT or UVOT data for this trigger.
  Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
• GCN Circular #11207
  T. N. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), (i.e. the Swift-BAT team):
  Using the data set from T-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100904A (trigger #433273) (Ukwatta, et al., GCN Circ. 11203). The BAT ground-calculated position is RA, Dec = 172.907, -16.185 deg which is

     RA(J2000)  =  11h 31m 37.6s
     Dec(J2000) = -16d 11' 05.5"
  

  with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 30%.
  The mask-weighted light curve shows two overlapping peaks. The first starts around T-18 sec and peaks around T-13 sec. The second peaks around T+3 sec. T90 (15-350 keV) is 31.3 +/- 7.9 sec (estimated error including systematics).
  The time-averaged spectrum from T-14.5 to T+23.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.67 +/- 0.16. The fluence in the 15-150 keV band is 1.3 +/- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+2.29 sec in the 15-150 keV band is 1.6 +/- 0.3 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/433273/BA/
• GCN Circular #11217
  J.C. Tello, J. Gorosabel, A.J. Castro-Tirado (IAA-CSIC, Granada) P. Kubanek (IAA-CSIC and IPL-UV) W. Allen (Vintage Lane Obs.) and Ph. Yock (Auckland Univ.), report on behalf of a larger collaboration:
  "We have carried out observations of the Swift GRB 100904A (Ukwatta et al. GCNC 11203) on Sep 4.2982 - 4.3145 UT (~5.98 hr after the onset of the burst, mean observing time) with the 0.6m Yock-Allen robotic telescope (BOOTES-3) located in Blenheim, New Zealand. Observations were carried out at high airmass (~ 7).
  We do not detect any optical source within the Swift-BAT refined analysis error circle (Ukwatta et al. GCNC 11207). The 3 sigma limiting magnitude of the co-added unfiltered image (Texp=16x60s) is R ~ 18.0, using USNO-B1.0 as photometric reference."