Gamma-ray Burst 160503A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Wed 04 May 16 02:56:32 UT
  NOTICE_TYPE:     Fermi-LAT Offline Position
  TRIGGER_NUM:     483975395
  GRB_RA:            0.541d {+00h 02m 10s} (J2000), 
                     0.750d {+00h 03m 00s} (current),
                   359.901d {+23h 59m 36s} (1950)
  GRB_DEC:          -1.928d {-01d 55' 39"} (J2000),
                    -1.837d {-01d 50' 12"} (current),
                    -2.206d {-02d 12' 22"} (1950)
  GRB_ERROR:       31.80 [arcmin radius, 90% containment, statistical only]
  GRB_DATE:        17511 TJD;   124 DOY;   16/05/03
  GRB_TIME:        48992.00 SOD {13:36:32.00} UT 
  TRIGGER_ID:      0x0
  MISC:            0x40000000
  SUN_POSTN:        41.63d {+02h 46m 30s}  +16.06d {+16d 03' 52"}
  SUN_DIST:         44.16 [deg]   Sun_angle= 2.7 [hr] (West of Sun)
  MOON_POSTN:        6.33d {+00h 25m 18s}   +1.09d {+01d 05' 19"}
  MOON_DIST:         6.30 [deg]  
  MOON_ILLUM:      11 [%]
  GAL_COORDS:       95.75,-62.17 [deg] galactic lon,lat of the burst (or transient) 
  ECL_COORDS:      359.73, -1.98 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        Fermi LAT Offline position.
  COMMENTS:        This Notice was ground-generated -- not flight-generated.
  COMMENTS:        It is the result of human-in-the-loop processing.
  COMMENTS:        This is a human generated position of a LAT ground detection.
  COMMENTS:        This source corresponds to GBM trigger.
  

• GCN Circular #19379
  N. Omodei, G. Vianello (Stanford), J. Racusin (GSFC), E. Bissaldi (INFN Bari)
  report on behalf of the Fermi-LAT team:
  The Fermi-LAT detected high-energy emission from GRB 160503A which triggered the Fermi-GBM at 13:36:32.01 on May, 03, 2016 (trigger 483975395 / 160503567).
  The best LAT on-ground location is found to be:
  RA, Dec = 0.54, -1.93 (degrees, J2000) with an error radius of 0.52 deg (90 % containment, statistical error only).
  This was 25 deg from the LAT boresight at the time of the trigger. The event is faint and soft, but detected over a long time scale (10 ks). No events at GeV energies and above have been observed. A Swift ToO has been requested for this burst. The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it).
  The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
• GCN Circular #19380
  B. Mailyan (UAH) and K. Toelge (MPE) report on behalf of the Fermi GBM Team:
  "At 13:36:32.008 UT on 03 May 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160503A (trigger 483975396 / 160503567), which was also detected by the LAT (N. Omodei et al. 2016, GCN 19379) The GBM on-ground location is consistent with the LAT position.
  The angle from the Fermi LAT boresight at the GBM trigger time is 25 degrees.
  The GBM light curve consists of two peaks with a duration (T90) of about 59.4 s (50-300 keV). The time-averaged spectrum from T0-4.9 s to T0+28.9 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.28 +/- 0.14 and the cutoff energy, parameterized as Epeak, is 138.7 +/- 33.5 keV.
  The event fluence (10-1000 keV) in this time interval is (2.15 +/- 0.25)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.58 s in the 8-1000 keV band is 2.5 +/- 0.2 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."