Forecasted masses for seven thousand KOIs

Abstract

Recent transit surveys have discovered thousands of planetary candidates with directly measured radii, but only a small fraction have measured masses. Planetary mass is crucial in assessing the feasibility of numerous observational signatures, such as radial velocities (RVs), atmospheres, moons and rings. In the absence of a direct measurement, a data-driven, probabilistic forecast enables observational planning and so here we compute posterior distributions for the forecasted mass of approximately seven thousand Kepler Objects of Interest (KOIs). Our forecasts reveal that the predicted RV amplitudes of Neptunian planets are relatively consistent, as a result of transit survey detection bias, hovering around the few m/s level. We find that mass forecasts are unlikely to improve through more precise planetary radii, with the error budget presently dominated by the intrinsic model uncertainty. Our forecasts identify a couple of dozen KOIs near the Terran-Neptunian divide with particularly large RV semi-amplitudes which could be promising targets to follow-up, particularly in the near-IR. With several more transit surveys planned in the near-future, the need to quickly forecast observational signatures is likely to grow and the work here provides a template example of such calculations.