Proper motions of Local Group dwarf spheroidal galaxies I: First
  ground-based results for Fornax
  In this paper we present in detail the methodology and the first results of a
ground-based program to determine the absolute proper motion of the Fornax
dwarf spheroidal galaxy.
  The proper motion was determined using bona-fide Fornax star members measured
with respect to a fiducial at-rest background spectroscopically confirmed
Quasar, \qso. Our homogeneous measurements, based on this one Quasar gives a
value of (\mua,\mud)$ = (0.64 \pm 0.08, -0.01 \pm 0.11)$ \masy. There are only
two other (astrometric) determinations for the transverse motion of Fornax: one
based on a combination of plates and HST data, and another (of higher internal
precision) based on HST data. We show that our proper motion errors are similar
to those derived from HST measurements on individual QSOs. We provide evidence
that, as far as we can determine it, our motion is not affected by magnitude,
color, or other potential systematic effects. Last epoch measurements and
reductions are underway for other four Quasar fields of this galaxy, which,
when combined, should yield proper motions with a weighted mean error of
$\sim50\,\mu$as y$^{-1}$, allowing us to place important constraints on the
orbit of Fornax.
