HD 83443 c

After a long waiting here is finally the elusive second planet of HD 83443, much farther away than expected

HD 83443c: A highly eccentric giant planet on a 22-year orbit

Quote :

We report the discovery of a highly eccentric long-period Jovian planet orbiting the hot-Jupiter host 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 m sin i =1.35^+0.07_−0.06 M_J, moving on an orbit with a=8.0±0.8 AUs 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^+0.5_-0.2M_Jup. 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. HD 83443 is a rare example of a system hosting a hot Jupiter and an exterior planetary companion. The high eccentricity of HD 83443c 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.