We examine eight known single-eccentric planetary systems in light of recently released large data archives and new analysis techniques .
For four of these systems ( HD 7449 , HD 65216 , HD 89744 , HD 92788 ) we find evidence for additional long-period companions .
HD 65216c is a Jupiter analog , with a period of 14.7 yr , e = 0.18 , and m sin i of 2 M _ { Jup } , whilst the remaining candidate companions move on as-yet-incomplete orbits .
Our results highlight the importance of revisiting the analysis of known exoplanetary systems when new data become available , particularly given the possibility that poorly-sampled data might previously have led to the detection of a ’ false-positive ’ single eccentric planet , when the system in question actually contains two ( or more ) planets on near-circular orbits .