Gamma-ray Burst 000620

On June 20, 2000 at 05:33:38 UT a burst was detected by the GRBM and WFC aboard BeppoSAX.

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN notice #716/717 and BeppoSAX Mail n.00/19
  On June 20, 5:33:38 U.T. a GRB (GRB000620) has been detected simultaneosly by the GRBM and WFC aboard BeppoSAX.
  Preliminary coordinates from WFC are:

  R.A.(2000)= 113.872
  DEC(2000)= +69.199
  

  The error radius at this stage of analysis is 5'.
• GCN notice #718 and BeppoSAX Mail n.00/20
  Refined coordinates of GRB000620 from WFC are:

  R.A.(2000)= 113.821
  DEC.(2000)= 69.193
  

  The error radius is 3.6'.
• GCN notice #722
  G. Tassone, M.R Daniele, A. Paolino, Scientific Operation Centre, Telespazio, Roma, M.J.S. Smith, J. in't Zand, Space Research Organization of the Netherlands (SRON), Utrecht, F. Frontera, C. Guidorzi, E. Montanari, Universita' di Ferrara, Ferrara, L. Amati, TESRE/CNR, Bologna, G. Gandolfi, M. Feroci and L.Piro, IAS/CNR, Roma, report:
  The BeppoSAX Gamma Ray Burst Monitor (GRBM) and Wide Field Camera (WFC unit 2) observed a gamma-ray burst on June 20.23169 UT. A preliminary analysis reveals a duration of about 15 s in the GRBM, with a peak photon countrate of 934 cts/s in the 40-700 keV energy band. In the WFC, the duration is about 20 s and the peak flux is 2.8 Crab (2-26 keV). The position of the X-ray counterpart is R.A.= 7h 35m 17.2s Decl.= +69d 11' 35" (equinox 2000.0) with a 99% error radius of 3.6'. A follow-up NFI observation could not be performed due to solar constraints.
• GCN notice #723
  K. Hurley, on behalf of the Ulysses GRB team, T. Cline, E. Mazets, and S. Golenetskii, on behalf of the Konus Wind GRB team, and F. Frontera, C. Guidorzi, and E. Montanari, on behalf of the BeppoSAX GRBM team, report:
  This burst (GCN 722) was detected by Ulysses, Konus Wind, and the BeppoSAX GRBM. We have triangulated it to an annulus centered at RA(2000)=312.137 o, Decl(2000)=+32.151 o, with radius 77.784 +/- 0.043 degrees (3 sigma). This annulus intersects the BeppoSAX WFC error circle to form an ~28 sq. arcmin. error region, reducing the area of the error circle by ~25%. A map may be found at ssl.berkeley.edu/ipn3/000620. This annulus may be improved.
• GCN notice #724
  C.Bartolini, R.Gualandi, A.Guarnieri, A.Piccioni, Astronomy Department, Bologna University and Bologna Astronomical Observatory, and E. Palazzi, E. Pian, N.Masetti, ITeSRE-CNR, Bologna report:
  On June 20.88 UT we have imaged the field of GRB000620 (G.Gandolfi et al. GCN n.718) with the 152 cm telescope of Loiano, R color (1800 sec. exposure). A preliminary quick inspection of the field does not show any obvious object brighter than POSS1.
• GCN notice #725
  Guidubaldi D., Valentini G., Osservatorio Astronomico di Collurania Teramo - Italy, report:
  Starting at June 20.86, the 4'x4' center field of the BeppoSAX error-box (GCN 718) was imaged in poor seeing condition using the TNT 0.72 meter optical telescope at Teramo. We obtained two 600 sec R-band images. The reached limit magnitude of the combined one is about R= 19.
  Neither the single images, nor the summed one, reveals any variable or new source when compared with the Digital Sky Survey (DSS-II). Further observations are planned.
• GCN notice #728
  N. Masetti, E. Palazzi, E. Pian, F. Frontera (ITESRE, CNR, Bologna), M. Tichy, J. Ticha (Klet Observatory), R. Hudec (ASU, Ondrejov) and G. Gandolfi (IAS, CNR, Rome), on behalf of a larger collaboration, report:
  Unfiltered optical images of the field of GRB000620 (GCN #716), were acquired on 2000 June 20.91 with the 0.57-meter telescope (+CCD camera SBIG ST-8) of the Klet Observatory, Czech Republic, for a total exposure time of 600 sec. The seeing was around 3 arcsec as the field can only be observed at high airmass (~2.5) in this period.
  No new or noticeable object down to a magnitude ~20 is detected inside the BeppoSAX+IPN error box (GCNs #718, #723) when we compare our image with the DSS-II Digital Sky Survey.
• GCN notice #729
  A. Di Paola, L.A. Antonelli, R. Speziali, Osservatorio Astronomico di Roma, Italy, A. Arkarov, V. Larionov, Pulkovo Astronomical Observatory, Russia, M. Dolci, Osservatorio Astronomico di Teramo, on behalf of a larger collaboration report:
  On June 20.86 U.T. and on June 21.83 U.T. we imaged the BeppoSAX error-box of GRB000620 (GCN #718) using the AZT-24 1.1-meter telescope at Campo Imperatore (AQ). We obtained two mosaics of J-band images for a total exposure time of 1500 s in each mosaic. The limiting mag reached in the 2'.6x2'.6 central part of both mosaics is J=20.5 mag down to J=19.5 mag on the border and seeing has been around 2.5 arcsec during both observations.
  A comparison of the two observations does not reveal any new or variable object within the BeppoSAX+IPN error box (GCNs #718, #723).
• GCN notice #734
  J. Gorosabel (DSRI, Copenhagen), A. Henden (USRA/USNO) on behalf of the USNO GRB team, A.J. Castro-Tirado (LAEFF-INTA, Madrid, and IAA-CSIC, Granada), P. Gutierrez (IAA-CSIC, Granada), S. Klose (Thueringer Landessternwarte, Tautenburg), J. Greiner (AIP, Potsdam), J.M. Castro Ceron (ROA, San Fernando), E. Costa and M. Feroci, on behalf of the BSAX team (IAS, Rome), report on behalf of a larger European collaboration:
  We have obtained R-band images of the GRB 000620 field (GCN #716, #722) with the 1.0-m USNO and 2.2-m CAHA telescopes, as follows:

        Date(UT)      T-T0(hr)    Exp.(s)  Seeing(")    Lim. Mag.
   -------------------------------------------------------------
    20.465 -- 20.472   5.67      2x300       3.0"         19.8
    20.898 -- 20.905  16.08        600       2.0"         21.7
    21.872 -- 21.879  27.45        600       1.5"         22.1
    22.869 -- 22.885  63.49      3x600       1.5"         22.8
   -------------------------------------------------------------
  

  No object within the BSAX WFC error box brighter than R ~ 19.5 is found to exhibit a variation larger than 0.25 mag.
• GCN notice #750
  E. Berger (Caltech), D. A. Frail (NRAO), and K. Becker (Oberlin) report on behalf of a larger collaboration:
  We have observed the BeppoSax error circle for GRB000620 (GCN #718) using the VLA on several occasions starting on June 20.93 UT. Observations at 4.86 and 8.46 GHz revealed only one uncatalogued source inside the combined BeppoSax+IPN error region (GCN #723). The position of the source is RA: 07:34:52.9, DEC: 69:09:07.8 with a conservative 1" error in both. We observed this source on six different days, ending 19 days after the burst. There is no evidence that the source is varying substantially at either frequency. We therefore conclude that it is unlikely that this source is the radio afterglow of GRB000620.