TOI-4640 b
TOI-4640 b is a mini-Neptune orbiting TOI-4640 in the constellation Cetus. It lies about 799 light-years from Earth and was discovered in 2026 using the transit method.
How Big Is TOI-4640 b?
TOI-4640 b has a radius of 2.84 times that of Earth.
Is TOI-4640 b in the Habitable Zone?
The position of TOI-4640 b relative to the habitable zone of TOI-4640 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-4640: 0.793–1.870 AU (conservative: 1.004–1.773 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-4640 b — one full orbit around TOI-4640 — lasts 2.69 Earth days, shorter than Mercury's 88-day year.
How Was TOI-4640 b Discovered?
TOI-4640 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-4640 b?
TOI-4640 b is 799.4 light-years (245.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1227. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 14,069,440 years to make the journey.
The Host Star: TOI-4640
TOI-4640
- Surface temperature
- 5,743 K (Sun: 5,772 K)
- Radius
- 1.07 R☉
Planetary System
TOI-4640 b is the only planet known to orbit TOI-4640 so far.
TOI-4640 b — Complete Data
| Radius | 2.843 Earth radii (0.254 Jupiter radii) |
|---|---|
| Orbital period | 2.69 days |
| Distance from Earth | 799.4 light-years (245.1 parsecs) |
| Constellation | Cetus |
| 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-4640 b
Is TOI-4640 b habitable?
TOI-4640 b is not known to orbit within the habitable zone of TOI-4640, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is TOI-4640 b?
TOI-4640 b is about 799 light-years from Earth in the constellation Cetus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 14,069,440 years to get there.
How big is TOI-4640 b compared to Earth?
TOI-4640 b has 2.84 times the radius of Earth.
How long is a year on TOI-4640 b?
One orbit around TOI-4640 takes 2.7 Earth days — short enough that 136 of its years would fit into one Earth year.
Explore TOI-4640 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
