 The eccentric orbit became clear with the discovery of the brown dwarf within the system.The orbit of an Earth-like planet would need to be centered within 0.68 AU (around the orbital distance of Venus), which in a Keplerian system means a 240-day orbital period.In a 2006 simulation with the brown dwarf, 54 Piscium b's orbit "sweeps clean" most test particles within 0.5 AU, leaving only asteroids "in low-eccentricity orbits near the known planet’s apastron distance, near the 1