TOI-1801 b
TOI-1801 b is a super-Earth orbiting the M0.5+/-0.5 V star TOI-1801 in the constellation Leo. It lies about 100 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-1801 b?
TOI-1801 b has a radius of 2.08 times that of Earth. Its mass is 5.7 times that of Earth, giving it a density of 3.70 g/cm³ — between that of rocky and gaseous planets.
Is TOI-1801 b in the Habitable Zone?
The position of TOI-1801 b relative to the habitable zone of TOI-1801 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-1801: 0.197–0.503 AU (conservative: 0.250–0.477 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 ›
Temperature on TOI-1801 b
The equilibrium temperature of TOI-1801 b is about 494 K (221 °C) — hotter than anywhere on Earth. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on TOI-1801 b — one full orbit around TOI-1801 — lasts 10.6 Earth days, shorter than Mercury's 88-day year.
How Was TOI-1801 b Discovered?
TOI-1801 b was discovered in 2023 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-1801 b?
TOI-1801 b is 100.1 light-years (30.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1926. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,761,760 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-1801 b scores 0.37, ranking #601 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1801
TOI-1801 b belongs to a system of 2 stars; it orbits TOI-1801.
TOI-1801
- Spectral type
- M0.5+/-0.5 V
- Surface temperature
- 3,863 K (Sun: 5,772 K)
- Mass
- 0.56 M☉
- Radius
- 0.55 R☉
- Luminosity
- 0.0589 L☉
- Age
- 0.7 billion years (Sun: 4.6)
Planetary System
TOI-1801 b is the only planet known to orbit TOI-1801 so far.
TOI-1801 b — Complete Data
| Radius | 2.079 Earth radii (0.186 Jupiter radii) |
|---|---|
| Mass | 5.74 Earth masses (0.018 Jupiter masses) |
| Density | 3.70 g/cm³ (Earth: 5.51) |
| Orbital period | 10.64 days |
| Equilibrium temperature | 494 K (221 °C) |
| Earth Similarity Index | 0.37 |
| Distance from Earth | 100.1 light-years (30.7 parsecs) |
| Constellation | Leo |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-10-21. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1801 b
Is TOI-1801 b habitable?
TOI-1801 b is not known to orbit within the habitable zone of TOI-1801, and as a super-Earth it is an unlikely candidate for life as we know it.
How far away is TOI-1801 b?
TOI-1801 b is about 100 light-years from Earth in the constellation Leo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,761,760 years to get there.
How big is TOI-1801 b compared to Earth?
TOI-1801 b has 2.08 times the radius of Earth and about 5.7 times its mass.
How long is a year on TOI-1801 b?
One orbit around TOI-1801 takes 10.6 Earth days — short enough that 34 of its years would fit into one Earth year.
Explore TOI-1801 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.
