Terrestrial planet · Barnard's star

Barnard d

ExoplanetsDiscovered 2025

Scientific overview

Barnard d is a terrestrial planet orbiting Barnard's star, completing an orbit every 2 days, about 6 light-years from Earth. It was discovered in 2025 using the radial velocity method.

Host star

Barnard's Star

Spectral type

M3.5-4 V

Temperature

3,195 K

Mass

0.162 M☉

Planetary system — Barnard's star system

View the Barnard's star system (4 known planets).

Planet	Class	Radius (R⊕)	Period (d)	Distance (ly)
Barnard dRadial Velocity · 2025	Terrestrial planet	0.69	2.3402	6
Barnard bRadial Velocity · 2024	Terrestrial planet	0.72	3.1542	6
Barnard cRadial Velocity · 2025	Terrestrial planet	0.74	4.1244	6
Barnard eRadial Velocity · 2025	Terrestrial planet	0.64	6.7392	6

Discovery and detection

Detection method

Radial Velocity Method

Discovery year

2025

Discovered at

Gemini Observatory

Knowledge connections

OrbitsBarnard's Star
Member of systemBarnard's star system
Discovered by methodRadial Velocity Method
Discovered atGemini Observatory
Catalogued inNASA Exoplanet Archive

Quick facts

Class: Terrestrial planet
Host star: Barnard's Star
Discovery method: Radial Velocity Method
Discovery year: 2025
Orbital period: 2.3402 d
Semi-major axis: 0.0188 AU
Eccentricity: 0.04
Radius: 0.69 R⊕
Mass: 0.26 M⊕
Density: 4.36 g/cm³ · derived
Equilibrium temp.: 483 K
Insolation: 10.04 S⊕
Distance: 6 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 density4.36 g/cm³derived
Formula & inputs
Formula: ρ = M / (4⁄3·π·r³) (v1.0.0, impl v1.0.0)
Inputs:
- massEarth = 0.26 M⊕ · NASA
- radiusEarth = 0.69 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.