Host star — Teegarden's Star
- Spectral type
- M7.0 V
- Temperature
- 3,034 K
- Radius
- 0.12 R☉
- Mass
- 0.10 M☉
- Luminosity
- 0.001 L☉
- Distance
- 3.8 pc (12.5 ly)
Red dwarf — the most common type of star. Cool and small.
Very cool — a faint red dwarf.
Teegarden's Star b
Orbits Teegarden's Star · 12.5 light-years from Earth
RockyRadial Velocity2019ESI 88 · Very Earth-like
Radius
1.05×
Earth
Mass
1.2×
Earth
Year
5d
Temp
277 K
4°C
Gravity
1.1×
Earth
Distance
12.5
ly
What it would be like
Teegarden's Star b is a rocky world, potentially similar in composition to Earth or Mars — a solid surface you could, in theory, stand on.
Surface gravity is about 1.1g — noticeably heavier what you're used to on Earth.
With an equilibrium temperature around 4°C, this planet sits in the temperature range where liquid water could potentially exist on the surface — a key ingredient for life as we know it.
A year here is only 4.9 Earth days. Seasons, if they exist, change in a matter of hours.
Earth comparison
Logarithmic bars so Jupiter-class planets fit the same scale as Earth-size worlds.
Radius1.05R⊕
1/25×Earth = 125×
Mass1.16M⊕
1/10000×Earth = 110000×
Surface gravity1.05g
1/100×Earth = 1100×
Equilibrium temp277 K(4°C)
0 KEarth 255 K2500 K
Side-by-side with Earth
Temperature in context
Liquid N₂Mars avgEarth eq.Earth sfc.Boiling H₂OVenus
Discovery & orbit
- Method
- Radial Velocity
- Year
- 2019
- Facility
- Calar Alto Observatory
- Semi-major axis
- 0.0259 AU
- Period
- 4.91 days
- Eccentricity
- 0.0300
- Density
- 5.51 g/cm³
Detected by the star's wobble — gravitational tug from the orbiting planet shifts spectral lines.
Mildly elliptical — similar to most Solar System planets.
Rocky composition likely. Earth is 5.51 g/cm³.
Discovered via · Radial velocity
The star's wobble — gravitational tug from the planet shifts its spectrum
A planet orbiting a star pulls it slightly back and forth. That motion compresses the star's light when moving toward us (blueshift) and stretches it away (redshift). Precision spectrographs detect the wobble at metres-per-second — enough to infer a planet's mass and orbit.
- Overall share
- ~19% of discoveries
- Best for
- Massive, close-in planets around nearby bright stars
Orbital Animation
Teegarden's StarTeegarden's Star bOrbitHabitable zone
Drag to rotate · scroll to zoomSemi-major axis: 0.026 AUEccentricity: 0.0300Period: 4.9 days
Hertzsprung–Russell Diagram
Where this host star sits among … exoplanet host stars. The main sequence band runs diagonally — giants and supergiants sit above, white dwarfs below.
OBAFGKMCurrent star
How far is 12.5 light-years?
- A light beam leaving Earth right now would arrive in 12.5 years.
- At Voyager 1's speed (17 km/s), the trip would take approximately 220,342 years.
- A radio signal sent today would arrive in 12.5 years — and the reply wouldn't come back for twice that.
Earth Similarity Index
88/1000 — Nothing like Earth100 — Identical to Earth
ESI combines radius similarity and equilibrium temperature similarity. Earth = 100. Mars ≈ 73. Venus ≈ 44. This score reflects two physical parameters only — not atmosphere, water, or magnetic field.