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 (3,232 °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
- Computed from mass and radius
- Spectral type
- M2.5V (red dwarf)
Motion through space
- Proper motion
- 1 arcseconds per year · its drift across our sky
- SIMBAD — 2020yCat.1350....0G, 2018A&A...616A...7S
- Radial velocity
- -34.6 km/s · approaching the Sun
- SIMBAD — 2020yCat.1350....0G, 2018A&A...616A...7S
- Speed across our line of sight
- 44.7 km/s
- Computed from proper motion and parallax
- Speed through space, relative to the Sun
- 56.5 km/s
- Computed from proper motion, parallax and radial velocity
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 (3,232 °C)
Radiation & temperature
- Luminosity
- 6.09 × 10²⁴ W · 0.0159 L☉
- Surface temperature
- 3,505 K (3,232 °C)
- Peak wavelength
- 827 nm · near-infrared (mostly invisible to the eye)
- Computed (Wien's law) from the surface temperature
Discovery & history
- Method
- Telescope
- 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
Images from open archives · credit shown per image