Contributions > By speaker > Handley Luke

Detection of long-period giant planets requires dedicated radial velocity (RV) observations over years or decades. The California Legacy Survey (CLS) is a high-precision RV program (~2 m/s precision) of 700 stars with a median baseline of 21 years and nearly 200 confirmed exoplanets. It stands out as one of the few uniform surveys sensitive to planets with ~decade-long orbits. However, CLS alone cannot paint a composite picture of cool giants due to persisting orbital degeneracies. Precision astrometry from Gaia DR4 will complement the CLS RV data, enabling a more complete interpretation of these rich datasets. We simulated realistic Gaia epoch astrometry for the CLS sample and show that joint modeling with CLS RVs is sensitive to the full 3D orbits and true masses of ~80 known giant planets. When DR4 arrives, this analysis will clarify the distinct formation pathways of giant planets and brown dwarfs in the outer regions of protoplanetary disks. Additionally, our initial injection-recovery tests suggest that mutual inclinations will be constrained in more than 10 systems hosting multiple giant planets, granting a unique glimpse into their dynamics.