  Using the recently published Gaia second data release which includes
measurements of the mean radial velocity of about 7.2 million stars, we
performed a systematic comparison with other existing radial velocity
catalogues in order to search for variations in the radial velocity
measurements, with the goal that detected differences may indicate that these
stars are possibly spectroscopic binaries stars with only one visible component
(SB1). We present a spectroscopic binary candidate stars catalogue containing
35,246 stars, compiled to encourage follow-up observations obtaining spectra at
different epochs of these stars orbits in order to verify their binarity and to
study these systems using radial velocity curves. Comparing the Gaia DR2
database with the K-M dwarf catalogue we found 16 stars that show radial
velocity variations. In a comparison with the Pulkovo radial velocity catalogue
of Hipparcos stars we identified a total of 539 SB1 candidate stars. In the
largest radial velocity catalogue available, the RAVE catalogue, we found a
total of 34,691 stars that show radial velocity variations when compared to the
Gaia DR2 data.
