Barnard's Star e
Planet· orbits Barnard's Star
Barnard's Star e — the outermost and lightest of the four (minimum mass ~0.19 Earth, among the lightest exoplanets known), on a 6.7-day orbit. Still too hot for liquid water; never imaged.
Open in 3D viewSee Barnard's Star e in the live, interactive 3D map
Key facts
Minimum mass
1.15 × 10²⁴ kg
0.193 M⊕
Year
6.74 Earth days
Distance from Barnard's Star
5,699,679 km
Science
Physical
- Minimum mass (m·sin i)
- 1.15 × 10²⁴ kg · 0.193 M⊕
- Radial-velocity detection measures m·sin i; the true mass depends on the unknown orbital inclination.
- Radius
- Not measured
- No transit — radius is a model estimate; true size unknown.
Orbital
- Semi-major axis
- 5,699,679 km
- From the NASA Exoplanet Archive (ESO/ESPRESSO radial-velocity orbit)
- Eccentricity
- 0.04
- From the NASA Exoplanet Archive (ESO/ESPRESSO radial-velocity orbit)
- Inclination
- 0.00 °
- From the NASA Exoplanet Archive (ESO/ESPRESSO radial-velocity orbit)
- Orbital period
- 6.7 days
- From the NASA Exoplanet Archive (ESO/ESPRESSO radial-velocity orbit)
- Perihelion
- 5,471,692 km
- Computed from the orbital elements
- Aphelion
- 5,927,666 km
- Computed from the orbital elements
- Mean orbital velocity
- 61.5 km/s
- Computed from the orbital elements
Composition
- Bulk composition
- Presumed rocky (minimum mass ~0.19 Earth — among the lightest exoplanets known); never 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
- 2.41 S⊕ · 2.41× the sunlight Earth receives
- Computed from Barnard's Star's luminosity and the orbital distance (inverse-square; Earth's sunlight = 1).
- Equilibrium temperature
- 340 K (67 °C)
- Computed model value (no atmosphere assumed), the coolest of the four — still too hot for liquid water; not measured.
Discovery & history
- Method
- Radial-velocity detection (stellar wobble)
- Name
- Designated 'e' as the fourth planet found around Barnard's Star, following the IAU convention of lettering planets in discovery order starting at 'b'.
Part of the compact four-planet family established from ESO/ESPRESSO data in 2025 — the outermost and least massive, one of the lightest worlds ever detected by radial velocity.
Images
Never imaged — this world is known only from the tiny gravitational tug it exerts on its star (radial velocity). An artist's impression of the whole system is on the system view; the planet's own appearance is unknown.