TOI-1820 b
TOI-1820 b is a hot Jupiter orbiting TOI-1820 in the constellation Coma Berenices. It lies about 811 light-years from Earth and was discovered in 2022 using the transit method.
How Big Is TOI-1820 b?
TOI-1820 b has a radius of 12.78 times that of Earth, or 1.14 times the radius of Jupiter. Its mass is 731 times that of Earth, giving it a density of 2.00 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-1820 b in the Habitable Zone?
TOI-1820 b orbits inside the inner edge of the habitable zone of TOI-1820. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-1820: 1.119–2.639 AU (conservative: 1.417–2.502 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-1820 b
The equilibrium temperature of TOI-1820 b is about 1,375 K (1,102 °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-1820 b — one full orbit around TOI-1820 — lasts 4.86 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.061 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.043).
How Was TOI-1820 b Discovered?
TOI-1820 b was discovered in 2022 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-1820 b?
TOI-1820 b is 810.5 light-years (248.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1216. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 14,264,800 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-1820 b scores 0.07, ranking #4,894 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1820
TOI-1820
- Surface temperature
- 5,734 K (Sun: 5,772 K)
- Mass
- 1.04 M☉
- Radius
- 1.51 R☉
- Age
- 11.0 billion years (Sun: 4.6)
Planetary System
TOI-1820 b is the only planet known to orbit TOI-1820 so far.
TOI-1820 b — Complete Data
| Radius | 12.778 Earth radii (1.140 Jupiter radii) |
|---|---|
| Mass | 731.01 Earth masses (2.300 Jupiter masses) |
| Density | 2.00 g/cm³ (Earth: 5.51) |
| Orbital period | 4.86 days |
| Orbital distance | 0.061 AU |
| Eccentricity | 0.043 |
| Equilibrium temperature | 1,375 K (1,102 °C) |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 810.5 light-years (248.5 parsecs) |
| Constellation | Coma Berenices |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-09-19. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1820 b
Is TOI-1820 b habitable?
No — TOI-1820 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-1820 b?
TOI-1820 b is about 811 light-years from Earth in the constellation Coma Berenices. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 14,264,800 years to get there.
How big is TOI-1820 b compared to Earth?
TOI-1820 b has 12.78 times the radius of Earth and about 731 times its mass.
How long is a year on TOI-1820 b?
One orbit around TOI-1820 takes 4.9 Earth days — short enough that 75 of its years would fit into one Earth year.
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