TOI-813 b
TOI-813 b is a cold gas giant orbiting the G0 IV star TOI-813 in the constellation Dorado. It lies about 858 light-years from Earth and was discovered in 2020 using the transit method.
How Big Is TOI-813 b?
TOI-813 b has a radius of 6.71 times that of Earth, or 0.60 times the radius of Jupiter.
Is TOI-813 b in the Habitable Zone?
TOI-813 b orbits inside the inner edge of the habitable zone of TOI-813. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-813: 1.510–3.545 AU (conservative: 1.912–3.361 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-813 b
The equilibrium temperature of TOI-813 b is about 610 K (337 °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. It receives 23.10 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-813 b — one full orbit around TOI-813 — lasts 83.9 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.423 AU — comparable to the inner Solar System.
How Was TOI-813 b Discovered?
TOI-813 b was discovered in 2020 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-813 b?
TOI-813 b is 858.3 light-years (263.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1168. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 15,106,080 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-813 b scores 0.17, ranking #4,110 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-813
TOI-813
- Spectral type
- G0 IV
- Surface temperature
- 5,907 K (Sun: 5,772 K)
- Mass
- 1.32 M☉
- Radius
- 1.94 R☉
- Age
- 3.7 billion years (Sun: 4.6)
Planetary System
TOI-813 b is the only planet known to orbit TOI-813 so far.
TOI-813 b — Complete Data
| Radius | 6.710 Earth radii (0.599 Jupiter radii) |
|---|---|
| Orbital period | 83.89 days |
| Orbital distance | 0.423 AU |
| Equilibrium temperature | 610 K (337 °C) |
| Stellar irradiation | 23.10× Earth |
| Earth Similarity Index | 0.17 |
| Distance from Earth | 858.3 light-years (263.1 parsecs) |
| Constellation | Dorado |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2020-01-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-813 b
Is TOI-813 b habitable?
No — TOI-813 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-813 b?
TOI-813 b is about 858 light-years from Earth in the constellation Dorado. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 15,106,080 years to get there.
How big is TOI-813 b compared to Earth?
TOI-813 b has 6.71 times the radius of Earth.
How long is a year on TOI-813 b?
One orbit around TOI-813 takes 83.9 Earth days.
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