Using red clump stars to correct the Gaia DR1 parallaxes
  Recent results have suggested that there is tension between the Gaia DR1 TGAS
distances and the distances obtained using luminosities determined by eclipsing
binaries or asteroseismology on red giant stars. We use the $K_s$-band
luminosities of red clump stars, identified and characterized by
asteroseismology, to make independent distance estimates. Our results suggest
that Gaia TGAS distances contain a systematic error that decreases with
increasing distance. We propose a correction to mitigate this offset as a
function of parallax that is valid for the Kepler field and values of parallax
that are less than ${\sim} 1.6 \rm \, mas$. For parallaxes greater than this we
find agreement with previously published values. We note that the TGAS
distances to the red clump stars of the open cluster M67 show a high level of
disagreement that is difficult to correct for.
