Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.
Facts
HD 69830 d has an equilibrium temperature between −50 and +50 °C.
How it was found
First planet found in 2006, by radial velocity (NASA Exoplanet Archive).
Its planets
HD 69830 b — 3.2 times Earth's width (estimated from its mass, not measured), a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 9 days; about 600 °C, hotter than boiling water; found in 2006 by radial velocity.
HD 69830 d — 4.5 times Earth's width (estimated from its mass, not measured), Neptune-sized; its year lasts 200 days; about 35 °C, between freezing and boiling; found in 2006 by radial velocity.
HD 69830 c — 3.5 times Earth's width (estimated from its mass, not measured), a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 32 days; about 290 °C, hotter than boiling water; found in 2006 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.