Radial velocity of HD 83443

By combining radial velocity data from four instruments (AAT/UCLES, Keck/HIRES, HARPS, Minerva-Australis) spanning more than two decades, we find evidence for a planet with msini=1.35_-0.06_^+0.07^M_J_, moving on an orbit with a=8.0{+/-}0.8au and eccentricity e=0.76{+/-}0.05. We combine our radial velocity analysis with Gaia EDR3/Hipparcos proper motion anomalies and derive a dynamical mass of 1.5_-0.2_^+0.5^M_J_.

We perform a detailed dynamical simulation that reveals locations of stability within the system that may harbor additional planets, including stable regions within the habitable zone of the host star. HD83443 is a rare example of a system hosting a hot Jupiter and an exterior planetary companion. The high eccentricity of HD83443c suggests that a scattering event may have sent the hot Jupiter to its close orbit while leaving the outer planet on a wide and eccentric path.