TOI-201 b
TOI-201 b is a cold gas giant orbiting the F star TOI-201 in the constellation Pictor. It lies about 371 light-years from Earth and was discovered in 2021 using the transit method.
How Big Is TOI-201 b?
TOI-201 b has a radius of 11.40 times that of Earth, or 1.02 times the radius of Jupiter. Its mass is 164 times that of Earth, giving it a density of 0.61 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-201 b in the Habitable Zone?
TOI-201 b orbits inside the inner edge of the habitable zone of TOI-201. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-201: 1.166–2.710 AU (conservative: 1.477–2.569 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Orbit and Year Length
A year on TOI-201 b — one full orbit around TOI-201 — lasts 53.0 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.303 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.28).
How Was TOI-201 b Discovered?
TOI-201 b was discovered in 2021 using the transit method, with observations from Transiting Exoplanet Survey Satellite (TESS).
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is TOI-201 b?
TOI-201 b is 371.2 light-years (113.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1655. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 6,533,120 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. TOI-201 b scores 0.11, ranking #4,366 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-201
TOI-201
- Spectral type
- F
- Surface temperature
- 6,423 K (Sun: 5,772 K)
- Mass
- 1.32 M☉
- Radius
- 1.31 R☉
- Luminosity
- 2.6100 L☉
- Age
- 0.7 billion years (Sun: 4.6)
The TOI-201 Planetary System
TOI-201 b is one of 3 known planets in the TOI-201 system. Its siblings:
TOI-201 b — Complete Data
| Radius | 11.400 Earth radii (1.017 Jupiter radii) |
|---|---|
| Mass | 164.00 Earth masses (0.516 Jupiter masses) |
| Density | 0.61 g/cm³ (Earth: 5.51) |
| Orbital period | 52.98 days |
| Orbital distance | 0.303 AU |
| Eccentricity | 0.275 |
| Earth Similarity Index | 0.11 |
| Distance from Earth | 371.2 light-years (113.8 parsecs) |
| Constellation | Pictor |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2026-05-07. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-201 b
Is TOI-201 b habitable?
No — TOI-201 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-201 b?
TOI-201 b is about 371 light-years from Earth in the constellation Pictor. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 6,533,120 years to get there.
How big is TOI-201 b compared to Earth?
TOI-201 b has 11.40 times the radius of Earth and about 164 times its mass.
How long is a year on TOI-201 b?
One orbit around TOI-201 takes 53.0 Earth days.
Explore TOI-201 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
