TOI-1811 b
TOI-1811 b is a hot Jupiter orbiting TOI-1811 in the constellation Coma Berenices. It lies about 418 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-1811 b?
TOI-1811 b has a radius of 11.14 times that of Earth, or 0.99 times the radius of Jupiter. Its mass is 309 times that of Earth, giving it a density of 1.23 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-1811 b in the Habitable Zone?
TOI-1811 b orbits inside the inner edge of the habitable zone of TOI-1811. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-1811: 0.415–1.014 AU (conservative: 0.526–0.961 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-1811 b
The equilibrium temperature of TOI-1811 b is about 962 K (689 °C) — hot enough to melt many metals. 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-1811 b — one full orbit around TOI-1811 — lasts 3.71 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.044 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.05).
How Was TOI-1811 b Discovered?
TOI-1811 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-1811 b?
TOI-1811 b is 418.2 light-years (128.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1608. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,360,320 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-1811 b scores 0.09, ranking #4,552 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1811
TOI-1811
- Surface temperature
- 4,766 K (Sun: 5,772 K)
- Mass
- 0.82 M☉
- Radius
- 0.77 R☉
- Luminosity
- 0.2753 L☉
- Age
- 5.9 billion years (Sun: 4.6)
Planetary System
TOI-1811 b is the only planet known to orbit TOI-1811 so far.
TOI-1811 b — Complete Data
| Radius | 11.142 Earth radii (0.994 Jupiter radii) |
|---|---|
| Mass | 308.93 Earth masses (0.972 Jupiter masses) |
| Density | 1.23 g/cm³ (Earth: 5.51) |
| Orbital period | 3.71 days |
| Orbital distance | 0.044 AU |
| Eccentricity | 0.052 |
| Equilibrium temperature | 962 K (689 °C) |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 418.2 light-years (128.2 parsecs) |
| Constellation | Coma Berenices |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-03-15. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1811 b
Is TOI-1811 b habitable?
No — TOI-1811 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-1811 b?
TOI-1811 b is about 418 light-years from Earth in the constellation Coma Berenices. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,360,320 years to get there.
How big is TOI-1811 b compared to Earth?
TOI-1811 b has 11.14 times the radius of Earth and about 309 times its mass.
How long is a year on TOI-1811 b?
One orbit around TOI-1811 takes 3.7 Earth days — short enough that 98 of its years would fit into one Earth year.