Kepler-442

Star

Kepler-442 — an orange K-type dwarf about 60% the Sun's mass, ~1,190 light-years away in Lyra. Cooler and milder than the Sun, it hosts a super-Earth in its habitable zone that ranks among the most Earth-like planets known.

Open in 3D viewSee Kepler-442 in the live, interactive 3D map

Key facts

Mass

1.21 × 10³⁰ kg

0.609 M☉

Radius

416,029 km

60% of the Sun's radius

Surface temperature

4,402 K (4129 °C)

Luminosity

4.63 × 10²⁵ W

Spectral type

K-type (orange dwarf)

Science

Physical

Mass: 1.21 × 10³⁰ kg · 0.609 M☉
Radius: 416,029 km · 60% of the Sun's radius
Density: 4,016 kg/m³ · 4× water
Spectral type: K-type (orange dwarf)

Rotation

Note: A quiet, distant orange dwarf; known only through its transiting planet.

Composition

By mass: A hydrogen/helium orange dwarf about 60% the Sun's mass — cooler, milder and longer-lived than the Sun. Its steady warmth places its super-Earth in a comfortable habitable zone.

Temperature

Surface: 4,402 K (4129 °C)

Radiation & temperature

Luminosity: 4.63 × 10²⁵ W · 0.121 L☉
Surface temperature: 4,402 K (4129 °C)
Peak wavelength: 658 nm · red light

Discovery & history

Name: A Kepler-mission catalogue designation; no proper name.

Confirmed as a planet host by NASA's Kepler telescope in 2015; its temperate super-Earth quickly became a reference point in discussions of potentially habitable worlds.

Images

NASA's comparison of Kepler's small habitable-zone planets — including Kepler-186 f and Kepler-442 b — with the Solar System (a NASA diagram). — NASA/Ames/JPL-Caltech (public domain) · Wikimedia Commons

Where to find it — in Lyra, the Lyre (IAU constellation chart). To the eye it is a single point of light; no telescope has imaged its surface. — IAU / Sky & Telescope, R. Sinnott & R. Fienberg (CC BY 3.0) · Wikimedia Commons

Images from open archives · credit shown per image