GRB 000529

On May 29 at 08:43:11 UT a strong burst (GRB000529) was detected
by BeppoSAX GRBM and WFC2 (2-26 keV).

The WFC position is:

R.A.= 2.348
Decl.= -61.531

with an error radius of 4'.

G. Gandolfi
on behalf of BeppoSAX Mission Scientist

K. Hurley, T. Cline, F. Frontera, C. Guidorzi, E. Montanari, and E. Mazets
report:

NEAR, Konus, and the BeppoSAX GRBM observed this burst (GCN #676
Loading...
 
 ).
(The NEAR XGRS detector has been turned back on and is operating
nominally; Ulysses data will not be available until tomorrow due
to the Memorial Day holiday).  Triangulation gives an annulus 
centered at RA(2000)=312.943 deg., Decl.(2000)=-26.625 deg., with radius
47.850 +/- 0.171 degrees (3 sigma).  This is consistent with,
but does not further constrain, the BeppoSAX WFC error box.  The
addition of Ulysses data is expected to improve this localization.

K. Hurley, on behalf of the Ulysses GRB team, T. Cline,  on behalf
of the NEAR and KONUS GRB teams, F. Frontera, C. Guidorzi, and E.
Montanari, on behalf of the BeppoSAX GRBM teams, and E. Mazets and
S. Golenetskii, on behalf of the KONUS-WIND GRB teams, report:

The Ulysses data for this burst (GCN #676
Loading...
 
 ) have been processed, and the
triangulation has been completed (GCN #678
Loading...
 
 ).  The Ulysses/ Earth
annulus is centered at RA(2000)=129.603, Decl.(2000)=-33.077, and has a
radius 76.204 +/- 0.054 deg.  This annulus intersects the BeppoSAX WFC
error circle at two points (RA, Decl.= 2.217, -61.555 and RA,
Decl.=2.406,-61.470) and reduces its area by ~30%.  A map has been
posted at ssl.berkeley.edu/ipn3/000529.  Further refinement to this
annulus is possible.

Paul Price, Tim Axelrod and Brian Schmidt report:

We have observed the error circle of GRB000529 (BeppoSAX mail 00/13) with the
50-inch telescope at Mount Stromlo Observatory.  Exposure was 3 x 300s, starting
at May 30.74 UT, with a limiting magnitude of R_M ~ 19.75 (where R_M refers to
the MACHO red band).  We find no OT candidate on comparison with the DSS.

A BeppoSAX follow up of GRB000529 with the Narrow Field Instruments
started around May 29 at 16:10 UT, i.e. about 7.5 hours after the GRB.

A preliminary analysis of the MECS (1.6-10 keV) data shows a possibly
fading source in the field.

R.A.(2000)= 2.451
DEC(2000)= -61.465

with an error radius of 2'.

A more detailed analysis is in progress.

G. Gandolfi
on behalf of BeppoSAX Mission Scientist

GRB000529: candidate X-ray afterglow
 
 M. Feroci, G. Gandolfi, E. Costa, L. Piro, P. Soffitta (IAS, CNR, Rome),
 L.A. Antonelli (OAR, Rome), L. Salotti (ASI, Rome), A. Coletta, 
 G. Celidonio, G. D'Andreta, M.R. Daniele, M. Stornelli (Telespazio, Rome),
 F. Frontera, E. Pian (ITESRE, CNR, Bologna), 
 L. Nicastro (IFCAI, CNR, Palermo), 
 J.J.M. in 't Zand, J. Heise, M.J. Smith, J.M. Muller (SRON, Utrecht), 
 on behalf of the BeppoSAX GRB Team, report:
 
 "The WFC error box (GCN #676
Loading...
 
 ) of GRB 000529 was observed by the
 Narrow Field Instruments starting about 7.5 hours after the GRB.
 A preliminary analysis of the first 23 ks of this observation
 reveals a previously unknown weak X-ray source, 1SAX J0009.8-6128
 at the position RA = 00h 09m 48.3s Dec = -61d 27' 53", with a
 conservative error radius of 2 arcminutes.
 No other source is significantly detected in the field.
 By dividing the available observation in two portions, the source
 is detected only in the first ~11ks with a count rate of
 (4.1+-1.0)E-3 count/s, corresponding to 2.8E-13 erg/cm2/s 
 (assuming a Crab-like energy spectrum). The lack of source detection 
 in the second ~12ks makes the new source a reasonable candidate as the 
 X-ray afterglow of GRB 000529.
 The position lies at 4.9 arcminutes from the WFC refined
 error box, and it therefore only partially overlaps with it. 
 We note that the position of the  NFI source is consistent with 
 the IPN annulus for this GRB (GCN #680
Loading...
 
 ).
 This message may be quoted in publications."

E. Palazzi, N. Masetti, E. Pian, F. Frontera (ITESRE, CNR, Bologna), A.J. 
Castro-Tirado (LAEFF, IAA), J. Hjorth (Univ. of Copenhagen), E. Rol,
E.P.J. van den Heuvel (Univ. of Amsterdam), J. Greiner (AIP), O. Marco, J.
Brewer and O. Hainaut (ESO), J.A.R. Caldwell (SAAO, observing on behalf of
the PLANET collaboration), N.  Suntzeff (CTIO), and M. Feroci (IAS, CNR,
Rome), on behalf of a larger collaboration, report: 

"Optical R-band images of the X-ray afterglow error box (GCNs #684
Loading...
 
 , #685
Loading...
 
 ) 
of GRB000529 (GCN #676
Loading...
 
 ) were acquired at three different epochs with four 
telescopes as reported in the following table:
 
     (UT)          Telescope      Texp(sec)   Seeing(")   R_lim(3-sigma)  
 
 2000 May 31.15     SAAO 1m         3000        1.4         22.7
      May 31.44     CTIO 4m          900        1.0         24.0
      May 31.44     ESO 2.2m         600        1.0         22.7
      Jun  3.42     ESO NTT          100        1.4         22.3
                      

Photometric calibration was performed using standard stars in the Landolt
T Phe sequence (Landolt 1992, AJ 104, 340).  Comparison of the images with
the DSS-II red survey does not reveal any new object above the DSS limit
(R~21.5). Unfortunately not all the images did cover the whole error box. 
The comparison among the overlapping regions of the acquired frames at the
different epochs does not reveal any object with significant brightness
variation down to a 3-sigma limiting magnitude of R ~22.3".

This message can be cited.