Search for (sub)stellar companions of exoplanet hosts by exploring the
  second ESA-Gaia data release
  We present the latest results of an ongoing multiplicity survey of exoplanet
hosts, which was initiated at the Astrophysical Institute and University
Observatory Jena, using data from the second data release of the ESA-Gaia
mission. In this study the multiplicity of 289 targets was investigated, all
located within a distance of about 500 pc from the Sun. In total, 41 binary,
and 5 hierarchical triple star systems with exoplanets were detected in the
course of this project, yielding a multiplicity rate of the exoplanet hosts of
about 16 %. A total of 61 companions (47 stars, a white dwarf, and 13 brown
dwarfs) were detected around the targets, whose equidistance and common proper
motion with the exoplanet hosts were proven with their precise Gaia DR2
astrometry, which also agrees with the gravitational stability of most of these
systems. The detected companions exhibit masses from about 0.016 up to 1.66
M$_\odot$ and projected separations in the range between about 52 and 9555 au.
