Gliese 357

Star

Gliese 357 - a red dwarf 30.8 light-years away in Hydra, host to three planets. The innermost, GJ 357 b, transits the star - a 'hot Earth' with a measured size - while the outermost, GJ 357 d, is a super-Earth in the habitable zone, among the nearer temperate worlds known.

Open in 3D viewSee Gliese 357 in the live, interactive 3D map

Key facts

Mass

6.80 × 10²⁹ kg

0.342 M☉

Radius

234,451 km

34% of the Sun's radius

Surface temperature

3,505 K (3232 °C)

Luminosity

6.09 × 10²⁴ W

Spectral type

M2.5V (red dwarf)

Science

Physical

Mass: 6.80 × 10²⁹ kg · 0.342 M☉
Radius: 234,451 km · 34% of the Sun's radius
Density: 12,601 kg/m³ · 13× water
Spectral type: M2.5V (red dwarf)

Rotation

Note: A quiet red dwarf; NASA's TESS caught its inner planet transiting in 2019.

Composition

By mass: A hydrogen/helium red dwarf about 0.34 solar mass and ~1.6% of the Sun's light, 30.8 light-years away in Hydra, host to three planets — one transiting, one in the habitable zone.

Temperature

Surface: 3,505 K (3232 °C)

Radiation & temperature

Luminosity: 6.09 × 10²⁴ W · 0.0159 L☉
Surface temperature: 3,505 K (3232 °C)
Peak wavelength: 827 nm · near-infrared (mostly invisible to the eye)

Discovery & history

Name: A catalogue designation (Gliese 357); the star has no proper name.

In 2019 NASA's TESS mission caught GJ 357 b transiting; follow-up with ESO's radial-velocity spectrographs revealed two more, non-transiting planets, including the habitable-zone super-Earth GJ 357 d.

Images

Where to find it — in Hydra, the Water Snake (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