Gamma-ray Burst 100917A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Fri 17 Sep 10 05:07:32 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     434360,   Seg_Num: 0
  GRB_RA:          289.265d {+19h 17m 04s} (J2000),
                   289.419d {+19h 17m 41s} (current),
                   288.543d {+19h 14m 10s} (1950)
  GRB_DEC:         -17.104d {-17d 06' 15"} (J2000),
                   -17.085d {-17d 05' 04"} (current),
                   -17.195d {-17d 11' 40"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       16120 [cnts]    Image_Peak=307 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   300     E_range: 25-100 keV
  BKG_INTEN:       143548 [cnts]
  BKG_TIME:        18145.81 SOD {05:02:25.81} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        15456 TJD;   260 DOY;   10/09/17
  GRB_TIME:        18205.78 SOD {05:03:25.78} UT
  GRB_PHI:         -106.08 [deg]
  GRB_THETA:        24.54 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     7.87 [sigma]
  IMAGE_SIGNIF:    7.15 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +2  -3  -5  +0 +40  +0 
  SUN_POSTN:       174.68d {+11h 38m 44s}   +2.30d {+02d 17' 57"}
  SUN_DIST:        114.29 [deg]   Sun_angle= -7.6 [hr] (East of Sun)
  MOON_POSTN:      288.24d {+19h 12m 59s}  -21.73d {-21d 43' 47"}
  MOON_DIST:         4.78 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:       20.28,-13.24 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      288.46,  5.11 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
  COMMENTS:        probably due to it occurring during a Malindi downlink session.  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 269.57,13.27 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Fri 17 Sep 10 05:08:01 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     434360,   Seg_Num: 0
  GRB_RA:          289.265d {+19h 17m 04s} (J2000),
                   289.419d {+19h 17m 41s} (current),
                   288.543d {+19h 14m 10s} (1950)
  GRB_DEC:         -17.104d {-17d 06' 15"} (J2000),
                   -17.085d {-17d 05' 04"} (current),
                   -17.195d {-17d 11' 40"} (1950)
  GRB_DATE:        15456 TJD;   260 DOY;   10/09/17
  GRB_TIME:        18205.78 SOD {05:03:25.78} UT
  TRIGGER_INDEX:   300
  GRB_PHI:         -106.08 [deg]
  GRB_THETA:        24.54 [deg]
  DELTA_TIME:      -75.00 [sec]
  TRIGGER_DUR:     4.096 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     7.87 [sigma]
  IMAGE_SIGNIF:    7.15 [sigma]
  LC_URL:          sw00434360000msb.lc
  SUN_POSTN:       174.69d {+11h 38m 44s}   +2.30d {+02d 17' 57"}
  SUN_DIST:        114.29 [deg]   Sun_angle= -7.6 [hr] (East of Sun)
  MOON_POSTN:      288.25d {+19h 13m 00s}  -21.73d {-21d 43' 44"}
  MOON_DIST:         4.77 [deg]
  MOON_ILLUM:      69 [%]
  GAL_COORDS:       20.28,-13.24 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:      288.46,  5.11 [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 = 269.57,13.27 [deg].  
  

  
• GCN Circular #11288
  O. M. Littlejohns (U Leicester), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), J. M. Gelbord (PSU), E. A. Hoversten (PSU), C. B. Markwardt (NASA/GSFC), C. Pagani (U Leicester), K. L. Page (U Leicester), A. Rowlinson (U Leicester), M. H. Siegel (PSU) and C. A. Swenson (PSU) report on behalf of the Swift Team:
  At 05:03:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100917A (trigger=434360). Swift did not slew to the burst location due to a moon observing constraint. The BAT on-board calculated location is RA, Dec 289.265, -17.104 which is

     RA(J2000) = 19h 17m 04s
     Dec(J2000) = -17d 06' 15"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a weak peak with a duration of about 4 sec. The peak count rate was ~400 counts/sec (15-350 keV), at ~1 sec after the trigger.
  Due to an observing constraint, Swift cannot slew to the BAT position. There will thus be no XRT or UVOT data for this trigger.
  This trigger will be in moon constraint until approximately 06:30 UT on the 19th of September.
  Burst Advocate for this burst is O. M. Littlejohns (oml2 AT star.le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
• GCN Circular #11289
  J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), O. M. Littlejohns (U Leicester), 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), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
  Using the data set from T-240 to T+960 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100917A (trigger #434360) (Littlejohns, et al., GCN Circ. 11288). The BAT ground- calculated position is RA, Dec = 289.250, -17.120 deg which is

      RA(J2000)  =  19h 17m 00.1s
      Dec(J2000) = -17d 07' 12.1"
  

  with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 62%.
  The mask-weighted light curve shows a FRED-like profile with rise time of ~5 sec and decay time of ~30 sec. T90 (15-350 keV) is 66 +- 22 sec (estimated error including systematics).
  The time-averaged spectrum from T-2.1 to T+76 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.67 +- 0.23. The fluence in the 15-150 keV band is 8.6 +- 1.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+3.22 sec in the 15-150 keV band is 0.6 +- 0.2 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/434360/BA/
• GCN Circular #11293
  Klotz A. (CESR-OMP), Gendre B. (IASF), Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:
  We imaged the field of GRB 100917A detected by SWIFT (trigger 434360) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile.
  The observations started 261s after the GRB trigger (15s after the notice). The elevation of the field decreased from 22 degrees above horizon and weather conditions were fair.
  We co-added a series of exposures. We do not detect any OT in the BAT refined position provided by Cummings et al. 2010 (GCNC 11289) with a limiting magnitude of:
  t0+261s to t0+531s : R > 14.1
  Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
  N.B. Galactic coordinates are lon= 20.2843 lat=-13.2388 and the galactic extinction in R band is 0.3 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
  This message may be cited.
• GCN Report 301.1
  GCN_Report 301.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_301_1.pdf by O.M. Littlejohns at U. Leicester titled: "Final report on Swift Observations of GRB 100917A"