Kepler-391, a K2 III-IV star, has 2 confirmed planets.
Measured
Distance
about 2,835 light-years
Star's spectral type
K2 III-IV
Confirmed planets
2
How far, from the Sun
About 2,840 light-years. To cross it:
Light2,840 years
Voyager 1's speed50.4 million years
Driving at 100 km/h30.6 billion years
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 2014, by transit (NASA Exoplanet Archive).
Its planets
Kepler-391 b — 2.5 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 7 days; about 660 °C, hotter than boiling water; found in 2014 by transit.
Kepler-391 c — 2.9 times Earth's width, a 'sub-Neptune' — bigger than Earth, smaller than Neptune; its year lasts 21 days; about 390 °C, hotter than boiling water; found in 2014 by transit.
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.