Host star — TOI-7166
- Spectral type
- M4.5+/-0.5
- Temperature
- 3,099 K
- Radius
- 0.22 R☉
- Mass
- 0.19 M☉
- Luminosity
- 0.004 L☉
- Distance
- 35.4 pc (116 ly)
Red dwarf — the most common type of star. Cool and small.
Very cool — a faint red dwarf.
TOI-7166 b
Orbits TOI-7166 · 116 light-years from Earth
Super-EarthTransit2025ESI 86 · Very Earth-like
Radius
2.01×
Earth
Mass
4.7×
Earth
Year
13d
Temp
249 K
-24°C
Gravity
1.2×
Earth
Distance
116
ly
Could life exist here?
AI analysisTOI-7166 b is a super-Earth roughly twice Earth's radius with a mass of 4.7 Earth masses, orbiting an M-dwarf star 116 light-years away. Its equilibrium temperature of 249 Kelvin places it well below Earth's 288 Kelvin, suggesting a frozen world—colder than Antarctica but potentially warm enough for liquid water if atmospheric greenhouse gases trap heat effectively. The planet orbits every 12.9 days at a distance of 0.0619 AU from its dim, low-mass host star, likely rotating synchronously so one face always points toward the star. That tidally locked geometry creates extreme temperature contrasts between day and night sides, complicating habitability prospects. However, the planet's robust habitability score of 86 out of 100 reflects its relatively stable orbit, Earth-like density of 3.18 g/cm³ suggesting a rocky composition, and position within a zone where water could exist. The main uncertainties are atmospheric composition and thickness—we don't yet know if this world has retained an atmosphere capable of moderating its harsh thermal extremes. TOI-7166 b's recent 2025 discovery via transit photometry makes it a prime candidate for atmospheric characterization by future space telescopes.
What it would be like
TOI-7166 b is a super-Earth — larger than our planet but likely still rocky or ice-rich. Whether it has a thin atmosphere like Mars or a crushing one like Venus remains unknown.
Surface gravity is about 1.2g — noticeably heavier what you're used to on Earth.
At -24°C, this world is cold — similar to Earth's polar regions or the surface of Mars. Water would likely be frozen, but subsurface liquid isn't ruled out.
An orbital period of 13 days makes the year 28.3× shorter than Earth's. You'd celebrate your birthday more often here.
Earth comparison
Logarithmic bars so Jupiter-class planets fit the same scale as Earth-size worlds.
Radius2.01R⊕
1/25×Earth = 125×
Mass4.70M⊕
1/10000×Earth = 110000×
Surface gravity1.16g
1/100×Earth = 1100×
Equilibrium temp249 K(-24°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
- Transit
- Year
- 2025
- Facility
- Transiting Exoplanet Survey Satellite (TESS)
- Semi-major axis
- 0.0619 AU
- Period
- 12.92 days
- Eccentricity
- 0.0000
- Density
- 3.18 g/cm³
Detected by measuring the tiny dip in starlight as the planet crosses in front of its star.
Nearly circular orbit.
Rocky composition likely. Earth is 5.51 g/cm³.
Discovered via · Transit
Tiny dip in starlight as the planet crosses in front of its star
A transit photometer watches a star nonstop and measures its brightness to ~0.01%. When a planet passes between us and the star, the star dims briefly — the deeper the dip, the bigger the planet. This is how Kepler and TESS found most known exoplanets.
- Overall share
- ~75% of all confirmed worlds
- Best for
- Earth-to-Neptune-sized planets on short orbits
Orbital Animation
TOI-7166TOI-7166 bOrbitHabitable zone
Drag to rotate · scroll to zoomSemi-major axis: 0.062 AUEccentricity: 0.0000Period: 12.9 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 116 light-years?
- A light beam leaving Earth right now would arrive in 116 years.
- At Voyager 1's speed (17 km/s), the trip would take approximately 2.0 million years.
- A radio signal sent today would arrive in 115.5 years — and the reply wouldn't come back for twice that.
Earth Similarity Index
86/1000 — 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.