TOI-2345 c
TOI-2345 c is a mini-Neptune orbiting the K star TOI-2345 in the constellation Fornax. It lies about 266 light-years from Earth and was discovered in 2025 using the transit method.
How Big Is TOI-2345 c?
TOI-2345 c has a radius of 2.45 times that of Earth. Its mass is 7.3 times that of Earth, giving it a density of 2.71 g/cm³ — between that of rocky and gaseous planets.
Is TOI-2345 c in the Habitable Zone?
TOI-2345 c orbits inside the inner edge of the habitable zone of TOI-2345. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-2345: 0.382–0.935 AU (conservative: 0.483–0.886 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-2345 c
The equilibrium temperature of TOI-2345 c is about 544 K (271 °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. It receives 14.57 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-2345 c — one full orbit around TOI-2345 — lasts 21.1 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.126 AU — closer to its star than Mercury is to the Sun.
How Was TOI-2345 c Discovered?
TOI-2345 c 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-2345 c?
TOI-2345 c is 266.3 light-years (81.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1760. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 4,686,880 years to make the journey.
The Host Star: TOI-2345
TOI-2345
- Spectral type
- K
- Surface temperature
- 4,687 K (Sun: 5,772 K)
- Mass
- 0.73 M☉
- Radius
- 0.73 R☉
- Luminosity
- 0.2310 L☉
- Age
- 6.3 billion years (Sun: 4.6)
The TOI-2345 Planetary System
TOI-2345 c is one of 2 known planets in the TOI-2345 system. Its siblings:
- TOI-2345 b (Super Earth)
TOI-2345 c — Complete Data
| Radius | 2.451 Earth radii (0.219 Jupiter radii) |
|---|---|
| Mass | 7.27 Earth masses (0.023 Jupiter masses) |
| Density | 2.71 g/cm³ (Earth: 5.51) |
| Orbital period | 21.06 days |
| Orbital distance | 0.126 AU |
| Equilibrium temperature | 544 K (271 °C) |
| Stellar irradiation | 14.57× Earth |
| Distance from Earth | 266.3 light-years (81.7 parsecs) |
| Constellation | Fornax |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-10-30. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-2345 c
Is TOI-2345 c habitable?
No — TOI-2345 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-2345 c?
TOI-2345 c is about 266 light-years from Earth in the constellation Fornax. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 4,686,880 years to get there.
How big is TOI-2345 c compared to Earth?
TOI-2345 c has 2.45 times the radius of Earth and about 7.3 times its mass.
How long is a year on TOI-2345 c?
One orbit around TOI-2345 takes 21.1 Earth days — short enough that 17 of its years would fit into one Earth year.
Explore TOI-2345 c in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
