  The space of phase-parameters (sky-position, frequency, spindowns) of a
coherent matched-filtering search for continuous gravitational waves from
isolated neutron stars shows strong global correlations (``circles in the
sky''). In the local limit this can be analysed in terms of a parameter-space
metric, but the global properties are less well studied. In this work we report
on our recent progress in understanding these global correlations analytically
for short to intermediate (less than a month, say) observation times and
neglecting spindowns. The location of these correlation-circles in
parameter-space is found to be determined mostly by the orbital velocity of the
earth, while the spin-motion of the detector and the antenna-patterns only
contribute significantly to the amplitude of the detection statistic along
these circles.
