Gliese 357 b
Planet· orbits Gliese 357
Gliese 357 b - a transiting 'hot Earth' (~1.8 Earth masses, ~1.2 Earth radii) orbiting every 3.9 days. Because it transits, its size and rocky density are measured; its hot dayside has never been directly imaged.
Open in 3D viewSee Gliese 357 b in the live, interactive 3D map
Key facts
Mass
1.09 × 10²⁵ kg
1.83 M⊕
Radius
7,645 km
1.2× wider than Earth
Surface gravity
12.5 m/s²
1.27× Earth's gravity
Year
3.93 Earth days
Distance from Gliese 357
5,385,523 km
Science
Physical
- Mass
- 1.09 × 10²⁵ kg · 1.83 M⊕
- Radius
- 7,645 km · 1.2× wider than Earth
- Density
- 5,839 kg/m³ · 5.8× water
- Computed from mass and radius
- Surface gravity
- 12.5 m/s² · 1.27× Earth's gravity
- Computed from mass and radius
- Escape velocity
- 13.8 km/s · 1.23× Earth's escape velocity
- Computed from mass and radius
Orbital
- Semi-major axis
- 5,385,523 km
- From the NASA Exoplanet Archive (transit + radial-velocity orbit)
- Eccentricity
- 0
- From the NASA Exoplanet Archive (transit + radial-velocity orbit)
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (transit + radial-velocity orbit)
- Orbital period
- 3.9 days
- From the NASA Exoplanet Archive (transit + radial-velocity orbit)
- Perihelion
- 5,385,523 km
- Computed from the orbital elements
- Aphelion
- 5,385,523 km
- Computed from the orbital elements
- Mean orbital velocity
- 99.6 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- A rocky planet of ~1.8 Earth masses and ~1.2 Earth radii — because it transits, its size and rocky density are measured. One of the nearest transiting rocky planets; its hot surface has never been imaged.
- Surface appearance
- Appearance based on ESO/M. Kornmesser's artist's concept. No spacecraft has imaged this world, so its real appearance is unknown — The surface shown is an artistic representation, shown only in Visual mode; Realism shows a plain spectral colour.
Radiation & temperature
- Insolation
- 12.3 S⊕ · 12.3× the sunlight Earth receives
- Computed from Gliese 357's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 518 K (245 °C)
- Computed model value for its 3.9-day orbit — hot; not a directly measured temperature.
Discovery & history
- Method
- Transit detection
- Name
- Designated 'b' under the IAU convention that letters a star's planets 'b', 'c', 'd'... in the order they are discovered (the star itself is the unwritten 'a').
Discovered transiting by NASA's TESS mission in 2019 - one of the nearest transiting rocky planets, and a prime target for atmospheric study.
Images
No official imagery available — this object has never been visited and no officially-licensed depiction exists.