Combining RV and high-contrast imaging techniques will be crucial in the coming decades: in an ideal case, RVs can allow us to predict planets' on-sky locations and then target these with high-contrast imaging and spectroscopy to understand their atmospheres. However, for systems where RV coverage spans less than one period, this introduces biases which limit our ability to reliably predict orbital solutions. One such case is Eps Ind Ab, first seen in RVs, but then, Matthews et al. (2024) imaged it with JWST and found it to be at the opposite location relative to prior orbital solutions from RV + astrometry orbital fitting.

I will present our work to understand whether this discrepancy arises from orbit-fitting methodology or from biases in the observational data. With joint RV + astrometry + imaging modelling and analyses, we aim to quantify how dataset selection and prior assumptions shape posterior distributions. I will also discuss our ongoing HARPS program to monitor eight nearby long-period planets, aiming to improve their orbital constraints in preparation for dedicated imaging & spectroscopic follow-up.