Terrestrial planet · GJ 581

GJ 581 e

ExoplanetsDiscovered 2009

Scientific overview

GJ 581 e is a terrestrial planet orbiting GJ 581, completing an orbit every 3 days, about 21 light-years from Earth. It was discovered in 2009 using the radial velocity method.

Host star

Gliese 581

Spectral type

M3.0 V

Temperature

3,500 K

Mass

0.295 M☉

Planetary system — GJ 581 system

View the GJ 581 system (3 known planets).

Planet	Class	Radius (R⊕)	Period (d)	Distance (ly)
GJ 581 eRadial Velocity · 2009	Terrestrial planet	1.38	3.1481	21
GJ 581 bRadial Velocity · 2005	Mini-Neptune	4.79	5.3686	21
GJ 581 cRadial Velocity · 2007	Mini-Neptune	2.5	12.9211	21

Discovery and detection

Detection method

Radial Velocity Method

Discovery year

2009

Discovered at

La Silla Observatory

Knowledge connections

OrbitsGliese 581
Member of systemGJ 581 system
Discovered by methodRadial Velocity Method
Discovered atLa Silla Observatory
Catalogued inNASA Exoplanet Archive

Quick facts

Class: Terrestrial planet
Host star: Gliese 581
Discovery method: Radial Velocity Method
Discovery year: 2009
Orbital period: 3.1481 d
Semi-major axis: 0.028 AU
Eccentricity: 0.012
Radius: 1.38 R⊕
Mass: 2.48 M⊕
Density: 5.20 g/cm³ · derived
Equilibrium temp.: 554 K
Insolation: 15.78 S⊕
Distance: 21 ly

Density is derived from the archive mass and radius via ρ = M / (4⁄3·π·r³); all other values are catalogued measurements.

Derived values

Computed from source-backed inputs via standard formulae — not observations. Every input and constant is traced below.

Bulk density5.20 g/cm³derived
Formula & inputs
Formula: ρ = M / (4⁄3·π·r³) (v1.0.0, impl v1.0.0)
Inputs:
- massEarth = 2.48 M⊕ · NASA
- radiusEarth = 1.38 R⊕ · NASA
Assumptions: M⊕ = 5.972e+24 kg, R⊕ = 6371000 m (IAU 2015 B3 nominal); Assumes a uniform sphere.
Limitations: Withheld above 30 g/cm³ (inconsistent mass/radius inputs).; Archive mass/radius carry no propagated uncertainty here.
Uncertainty: not propagated (inputs carry no catalogued uncertainty)
Computed as of 2026-06-29.

Quality & authority

Partial

Unreviewed

Description: Complete
Source coverage: Partial
Relationship coverage: Complete
Review coverage: None
Citation coverage: None
Image coverage: Not applicable

Data from the NASA Exoplanet Archive. See source quality.