SiO maser astrometry of the red transient V838 Monocerotis
  We present multi-epoch observations with the VLBA of SiO maser emission in
the v=1, J=1-0 transition at 43 GHz from the remnant of the red nova V838 Mon.
We model the positions of maser spots to derive a parallax of 0.166+/-0.060
mas. Combining this parallax with other distance information results in a
distance of 5.6+/-0.5 kpc, which agrees with an independent geometric distance
of 6.1+/-0.6 kpc from modeling polarimetry images of V838 Mon's light echo.
Combining these results, and including a weakly constraining Gaia DR2 parallax,
yields a best estimate of distance of 5.9+/-0.4 kpc. The maser spots are
located close to the peaks of continuum at ~225 GHz and SiO J=5-4 thermal
emission detected with ALMA. The proper motion of V838 Mon confirms its
membership in a small open cluster in the Outer spiral arm of the Milky Way.
