TOI-470 b
TOI-470 b is a Neptune-like planet orbiting the G star TOI-470 in the constellation Canis Major. It lies about 426 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-470 b?
TOI-470 b has a radius of 4.34 times that of Earth.
Is TOI-470 b in the Habitable Zone?
TOI-470 b orbits inside the inner edge of the habitable zone of TOI-470. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-470: 0.520–1.249 AU (conservative: 0.659–1.184 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-470 b
The equilibrium temperature of TOI-470 b is about 660 K (387 °C) — hot enough to melt many metals. 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-470 b — one full orbit around TOI-470 — lasts 12.2 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.119 AU — closer to its star than Mercury is to the Sun.
How Was TOI-470 b Discovered?
TOI-470 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-470 b?
TOI-470 b is 425.5 light-years (130.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1601. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,488,800 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-470 b scores 0.20, ranking #3,850 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-470
TOI-470
- Spectral type
- G
- Surface temperature
- 5,190 K (Sun: 5,772 K)
- Mass
- 0.87 M☉
- Radius
- 0.83 R☉
- Age
- 1.4 billion years (Sun: 4.6)
Planetary System
TOI-470 b is the only planet known to orbit TOI-470 so far.
TOI-470 b — Complete Data
| Radius | 4.340 Earth radii (0.387 Jupiter radii) |
|---|---|
| Orbital period | 12.19 days |
| Orbital distance | 0.119 AU |
| Equilibrium temperature | 660 K (387 °C) |
| Earth Similarity Index | 0.20 |
| Distance from Earth | 425.5 light-years (130.5 parsecs) |
| Constellation | Canis Major |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-08-22. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-470 b
Is TOI-470 b habitable?
No — TOI-470 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-470 b?
TOI-470 b is about 426 light-years from Earth in the constellation Canis Major. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,488,800 years to get there.
How big is TOI-470 b compared to Earth?
TOI-470 b has 4.34 times the radius of Earth.
How long is a year on TOI-470 b?
One orbit around TOI-470 takes 12.2 Earth days — short enough that 30 of its years would fit into one Earth year.
Explore TOI-470 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.
