Hugh Jones, Fabo Feng
The programme will focus on the determination of orbital parameters for over 2500 nearby stars which have high precision radial velocity observations along with Gaia and Hipparcos data. Based on our initial work with Gaia DR2 data, astrometric solutions significantly change the determined solutions for more than 23% of nearby stars. The expectation is that future Gaia data releases will allow the existence of significant astrometric signals arising from companions to be probed for most nearby stars. The combination of astrometric and radial velocity data will enable a much wider range of potential exoplanet orbits to be examined and should provide robust constraints on Jupiter analogues around nearby stars. Some of the planets we find will be around the very closest stars and be of immediate interest with facilities such as JWST. The long-term results from the programme can be expected to provide constraint on the variety of “Grand Tack” scenarios for the architectures of Solar Systems with similarities to our own and lead to improvements in the methodologies and available tools for the interpretation of datasets for more distant stars.
This project will make use of large archival data sets from precision radial velocity surveys. In particular, radial velocity data sets are hampered by stellar activity noise and further development of our new software tools to help deal with activity in large datasets will be necessary (e.g., building on Lisogorskyi, Jones, Feng et al. 2020). New Gaia data releases will be used to make joint astrometric and radial velocity solutions using our developing PEXO code (Feng, Lisogorskyi, Jones et al. 2019). This provides the opportunity to dramatically improve the robustness and sensitivity of searches for planets orbiting nearby stars.