TOI-4156 b
TOI-4156 b is a mini-Neptune orbiting TOI-4156 in the constellation Ursa Minor. It lies about 697 light-years from Earth and was discovered in 2026 using the transit method.
How Big Is TOI-4156 b?
TOI-4156 b has a radius of 2.54 times that of Earth.
Is TOI-4156 b in the Habitable Zone?
The position of TOI-4156 b relative to the habitable zone of TOI-4156 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-4156: 0.824–1.931 AU (conservative: 1.043–1.831 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-4156 b — one full orbit around TOI-4156 — lasts 4.46 Earth days, shorter than Mercury's 88-day year.
How Was TOI-4156 b Discovered?
TOI-4156 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-4156 b?
TOI-4156 b is 697.1 light-years (213.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1329. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 12,268,960 years to make the journey.
The Host Star: TOI-4156
TOI-4156
- Surface temperature
- 5,972 K (Sun: 5,772 K)
- Radius
- 1.04 R☉
The TOI-4156 Planetary System
TOI-4156 b is one of 2 known planets in the TOI-4156 system. Its siblings:
- TOI-4156 c (Mini Neptune)
TOI-4156 b — Complete Data
| Radius | 2.538 Earth radii (0.226 Jupiter radii) |
|---|---|
| Orbital period | 4.46 days |
| Distance from Earth | 697.1 light-years (213.7 parsecs) |
| Constellation | Ursa Minor |
| 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-4156 b
Is TOI-4156 b habitable?
TOI-4156 b is not known to orbit within the habitable zone of TOI-4156, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is TOI-4156 b?
TOI-4156 b is about 697 light-years from Earth in the constellation Ursa Minor. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 12,268,960 years to get there.
How big is TOI-4156 b compared to Earth?
TOI-4156 b has 2.54 times the radius of Earth.
How long is a year on TOI-4156 b?
One orbit around TOI-4156 takes 4.5 Earth days — short enough that 82 of its years would fit into one Earth year.