TOI-426 c
TOI-426 c is a cold gas giant orbiting the G2 V star TOI-426 in the constellation Lepus. It lies about 371 light-years from Earth and was discovered in 2026 using the radial velocity method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
Is TOI-426 c in the Habitable Zone?
TOI-426 c orbits within the optimistic habitable zone of TOI-426 — the broader region where liquid water might be possible under favorable atmospheric conditions.
Habitable zone of TOI-426: 0.733–1.728 AU (conservative: 0.928–1.638 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-426 c
The equilibrium temperature of TOI-426 c is about 319 K (46 °C) — in a range broadly comparable to Earth, whose equilibrium temperature is 255 K. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 1.73 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-426 c — one full orbit around TOI-426 — lasts 235.8 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 0.747 AU — comparable to the inner Solar System.
How Was TOI-426 c Discovered?
TOI-426 c was discovered in 2026 using the radial velocity method, with observations from La Silla Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is TOI-426 c?
TOI-426 c is 370.5 light-years (113.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1656. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 6,520,800 years to make the journey.
The Host Star: TOI-426
TOI-426
- Spectral type
- G2 V
- Surface temperature
- 5,750 K (Sun: 5,772 K)
- Mass
- 1.00 M☉
- Radius
- 0.99 R☉
- Luminosity
- 0.9506 L☉
- Age
- 1.6 billion years (Sun: 4.6)
The TOI-426 Planetary System
TOI-426 c is one of 2 known planets in the TOI-426 system. Its siblings:
- TOI-426 b (Super Earth)
TOI-426 c — Complete Data
| Mass (best estimate) | 444.00 Earth masses |
|---|---|
| Orbital period | 235.80 days |
| Orbital distance | 0.747 AU |
| Equilibrium temperature | 319 K (46 °C) |
| Stellar irradiation | 1.73× Earth |
| Distance from Earth | 370.5 light-years (113.6 parsecs) |
| Constellation | Lepus |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2026 |
Data: NASA Exoplanet Archive, last updated 2026-09-25. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-426 c
Is TOI-426 c habitable?
TOI-426 c orbits within the habitable zone of TOI-426, the region where liquid water could exist on a planet's surface. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is TOI-426 c?
TOI-426 c is about 371 light-years from Earth in the constellation Lepus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 6,520,800 years to get there.
How long is a year on TOI-426 c?
One orbit around TOI-426 takes 235.8 Earth days.
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