TOI-799 b
TOI-799 b is a mini-Neptune orbiting TOI-799 in the constellation Carina. It lies about 517 light-years from Earth and was discovered in 2026 using the transit method.
How Big Is TOI-799 b?
TOI-799 b has a radius of 2.07 times that of Earth.
Is TOI-799 b in the Habitable Zone?
The position of TOI-799 b relative to the habitable zone of TOI-799 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-799: 0.664–1.571 AU (conservative: 0.842–1.489 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 ›
Orbit and Year Length
A year on TOI-799 b — one full orbit around TOI-799 — lasts 5.55 Earth days, shorter than Mercury's 88-day year.
How Was TOI-799 b Discovered?
TOI-799 b was discovered in 2026 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-799 b?
TOI-799 b is 517.0 light-years (158.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1509. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 9,099,200 years to make the journey.
The Host Star: TOI-799
TOI-799
- Surface temperature
- 5,663 K (Sun: 5,772 K)
- Radius
- 0.92 R☉
Planetary System
TOI-799 b is the only planet known to orbit TOI-799 so far.
TOI-799 b — Complete Data
| Radius | 2.066 Earth radii (0.184 Jupiter radii) |
|---|---|
| Orbital period | 5.55 days |
| Distance from Earth | 517.0 light-years (158.5 parsecs) |
| Constellation | Carina |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2026 |
Data: NASA Exoplanet Archive, last updated 2026-04-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-799 b
Is TOI-799 b habitable?
TOI-799 b is not known to orbit within the habitable zone of TOI-799, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is TOI-799 b?
TOI-799 b is about 517 light-years from Earth in the constellation Carina. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 9,099,200 years to get there.
How big is TOI-799 b compared to Earth?
TOI-799 b has 2.07 times the radius of Earth.
How long is a year on TOI-799 b?
One orbit around TOI-799 takes 5.5 Earth days — short enough that 66 of its years would fit into one Earth year.
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