Gliese 251

Star

Gliese 251 - a red dwarf 18.2 light-years away in Gemini, host to two planets. The inner one is a temperate super-Earth, among the nearer such worlds to the Sun.

Open in 3D viewSee Gliese 251 in the live, interactive 3D map

Key facts

Mass

6.96 × 10²⁹ kg

0.35 M☉

Radius

250,452 km

36% of the Sun's radius

Surface temperature

3,342 K (3069 °C)

Luminosity

5.93 × 10²⁴ W

Spectral type

M3.0V (red dwarf)

Science

Physical

Mass: 6.96 × 10²⁹ kg · 0.35 M☉
Radius: 250,452 km · 36% of the Sun's radius
Density: 10,578 kg/m³ · 11× water
Spectral type: M3.0V (red dwarf)

Rotation

Note: A red dwarf whose temperate super-Earth was found by the CARMENES radial-velocity survey.

Composition

By mass: A hydrogen/helium red dwarf about 0.35 solar mass and ~1.5% of the Sun's light, 18.2 light-years away in Gemini, host to two planets — the inner a temperate super-Earth.

Temperature

Surface: 3,342 K (3069 °C)

Radiation & temperature

Luminosity: 5.93 × 10²⁴ W · 0.0155 L☉
Surface temperature: 3,342 K (3069 °C)
Peak wavelength: 867 nm · near-infrared (mostly invisible to the eye)

Discovery & history

Name: A catalogue designation (Gliese 251); the star also carries the name Wolf 294.

A nearby red dwarf whose temperate super-Earth was announced in 2020 by the CARMENES survey; a second, outer planet was confirmed in 2025 from continued radial-velocity monitoring.

Images

Where to find it — in Gemini, the Twins (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