Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.
How it was found
First planet found in 2002, by transit and radial velocity (NASA Exoplanet Archive).
Its planets
HD 50554 c — 1.3 times Earth's width, about Earth-sized — probably rocky; its year lasts 6 days; about 820 °C, hotter than boiling water; found in 2026 by transit.
HD 50554 d — 1.4 times Earth's width, about Earth-sized — probably rocky; its year lasts 28 days; about 380 °C, hotter than boiling water; found in 2026 by transit.
HD 50554 b — 13 times Earth's width (estimated from its mass, not measured), a giant, Jupiter-sized or more; its year lasts about 3 Earth years; about −80 °C, below freezing; found in 2002 by radial velocity.
NASA Exoplanet Archive, Planetary Systems Composite Parameters (fetched 2026-11-02). Composite values: where a planet's size or mass was not measured, the archive estimates it from the other.
This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.