TOI-1117 b
TOI-1117 b is a super-Earth orbiting the G5 V star TOI-1117 in the constellation Pavo. It lies about 547 light-years from Earth and was discovered in 2025 using the transit method.
How Big Is TOI-1117 b?
TOI-1117 b has a radius of 2.46 times that of Earth. Its mass is 8.9 times that of Earth, giving it a density of 3.30 g/cm³ — between that of rocky and gaseous planets.
Is TOI-1117 b in the Habitable Zone?
TOI-1117 b orbits inside the inner edge of the habitable zone of TOI-1117. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-1117: 0.454–1.074 AU (conservative: 0.575–1.018 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-1117 b
The equilibrium temperature of TOI-1117 b is about 1,538 K (1,265 °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 928 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-1117 b — one full orbit around TOI-1117 — lasts 2.23 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.033 AU — closer to its star than Mercury is to the Sun.
How Was TOI-1117 b Discovered?
TOI-1117 b was discovered in 2025 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-1117 b?
TOI-1117 b is 546.6 light-years (167.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1480. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 9,620,160 years to make the journey.
The Host Star: TOI-1117
TOI-1117
- Spectral type
- G5 V
- Surface temperature
- 5,635 K (Sun: 5,772 K)
- Mass
- 0.97 M☉
- Radius
- 1.05 R☉
- Luminosity
- 0.3600 L☉
- Age
- 4.4 billion years (Sun: 4.6)
The TOI-1117 Planetary System
TOI-1117 b is one of 3 known planets in the TOI-1117 system. Its siblings:
- TOI-1117 c (Super Earth)
- TOI-1117 d (Neptune-like)
TOI-1117 b — Complete Data
| Radius | 2.460 Earth radii (0.219 Jupiter radii) |
|---|---|
| Mass | 8.90 Earth masses (0.028 Jupiter masses) |
| Density | 3.30 g/cm³ (Earth: 5.51) |
| Orbital period | 2.23 days |
| Orbital distance | 0.033 AU |
| Equilibrium temperature | 1,538 K (1,265 °C) |
| Stellar irradiation | 928.00× Earth |
| Distance from Earth | 546.6 light-years (167.6 parsecs) |
| Constellation | Pavo |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-06-26. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1117 b
Is TOI-1117 b habitable?
No — TOI-1117 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-1117 b?
TOI-1117 b is about 547 light-years from Earth in the constellation Pavo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 9,620,160 years to get there.
How big is TOI-1117 b compared to Earth?
TOI-1117 b has 2.46 times the radius of Earth and about 8.9 times its mass.
How long is a year on TOI-1117 b?
One orbit around TOI-1117 takes 2.2 Earth days — short enough that 164 of its years would fit into one Earth year.
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