GCN Circular 138

F. E. Marshall (NASA/GSFC) and T. Takeshima (USRA/GSFC),
on behalf of the RXTE team, and P. Woods (UAH/MSFC) on
behalf of the BATSE team, report the detection
of an X-ray source during scans of the Locburst error region for
GRB 980706 (BATSE trigger 6904) with the PCA on RXTE.
A 4x8 degree region centered
on RA=161.82 and DEC=57.52 was scanned during a 2-hour
interval starting July 6.781, which is 2.7 hours after the burst.
A 90% confidence error region for the source has corners at
(RA, DEC) of (165.586, 57.801), (164.897, 55.836),
(164.366, 55.890), and (164.993, 57.860).
Since this error box intersects the preliminary IPN annulus
(GCN Circ. 129
Not found
 
 
), the X-ray source may be the
afterglow of the GRB. If so, the afterglow had a flux 
of about 2 mCrab in the 2-10 keV band 2.9 hours after the burst.
The intersection of the error box and the preliminary IPN annulus
is centered at (165.137, 57.385),and has a width of about 0.6 deg.
in RA and 0.026 deg. in DEC. However, the X-ray source
was not detected during two subsequent scans 1.5 hours later
indicating either unusual variability (a decay index of
at least 3 for an assumed power-law decay) or that the X-ray source
is not located in the intersection of the error box and the annulus.
The ROSAT-survey source J105825.9+564716, which lies
just outside the X-ray error box, is
an alternative identification of the X-ray source.
In this case, the X-ray source is unrelated to the GRB.