  We present new radial velocity measurements for three low-metallicity
solar-like stars observed with the SOPHIE spectrograph and its predecessor
ELODIE, both installed at the 193 cm telescope of the Haute-Provence
Observatory, allowing the detection and characterization of three new giant
extrasolar planets in intermediate periods of 1.7 to 3.7 years. All three
stars, HD17674, HD42012 and HD29021 present single giant planetary companions
with minimum masses between 0.9 and 2.5 MJup. The range of periods and masses
of these companions, along with the distance of their host stars, make them
good targets to look for astrometric signals over the lifetime of the new
astrometry satellite Gaia. We discuss the preliminary astrometric solutions
obtained from the first Gaia data release.
