TOI-2459 b
TOI-2459 b is a mini-Neptune orbiting TOI-2459 in the constellation Columba. It lies about 119 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-2459 b?
TOI-2459 b has a radius of 2.95 times that of Earth.
Is TOI-2459 b in the Habitable Zone?
The position of TOI-2459 b relative to the habitable zone of TOI-2459 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-2459: 0.287–0.720 AU (conservative: 0.364–0.683 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-2459 b
The equilibrium temperature of TOI-2459 b is about 445 K (172 °C) — hotter than anywhere on Earth. 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-2459 b — one full orbit around TOI-2459 — lasts 19.1 Earth days, shorter than Mercury's 88-day year.
How Was TOI-2459 b Discovered?
TOI-2459 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-2459 b?
TOI-2459 b is 119.4 light-years (36.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1907. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,101,440 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-2459 b scores 0.34, ranking #844 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-2459
TOI-2459
- Surface temperature
- 4,195 K (Sun: 5,772 K)
- Mass
- 0.66 M☉
- Radius
- 0.68 R☉
Planetary System
TOI-2459 b is the only planet known to orbit TOI-2459 so far.
TOI-2459 b — Complete Data
| Radius | 2.953 Earth radii (0.263 Jupiter radii) |
|---|---|
| Orbital period | 19.10 days |
| Equilibrium temperature | 445 K (172 °C) |
| Earth Similarity Index | 0.34 |
| Distance from Earth | 119.4 light-years (36.6 parsecs) |
| Constellation | Columba |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-05-26. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-2459 b
Is TOI-2459 b habitable?
TOI-2459 b is not known to orbit within the habitable zone of TOI-2459, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is TOI-2459 b?
TOI-2459 b is about 119 light-years from Earth in the constellation Columba. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,101,440 years to get there.
How big is TOI-2459 b compared to Earth?
TOI-2459 b has 2.95 times the radius of Earth.
How long is a year on TOI-2459 b?
One orbit around TOI-2459 takes 19.1 Earth days — short enough that 19 of its years would fit into one Earth year.
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