TOI-2578 b
TOI-2578 b is a hot Jupiter orbiting TOI-2578 in the constellation Perseus. It lies about 931 light-years from Earth and was discovered in 2026 using the transit method.
How Big Is TOI-2578 b?
TOI-2578 b has a radius of 19.66 times that of Earth, or 1.75 times the radius of Jupiter. Its mass is 167 times that of Earth, giving it a density of 0.12 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-2578 b in the Habitable Zone?
TOI-2578 b orbits inside the inner edge of the habitable zone of TOI-2578. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-2578: 1.318–3.068 AU (conservative: 1.670–2.909 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-2578 b
The equilibrium temperature of TOI-2578 b is about 1,778 K (1,505 °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. It receives 1,667 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-2578 b — one full orbit around TOI-2578 — lasts 3.46 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.050 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.10).
How Was TOI-2578 b Discovered?
TOI-2578 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-2578 b?
TOI-2578 b is 931.3 light-years (285.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1095. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 16,390,880 years to make the journey.
The Host Star: TOI-2578
TOI-2578
- Surface temperature
- 6,333 K (Sun: 5,772 K)
- Mass
- 1.27 M☉
- Radius
- 1.64 R☉
- Luminosity
- 3.3000 L☉
- Age
- 5.6 billion years (Sun: 4.6)
Planetary System
TOI-2578 b is the only planet known to orbit TOI-2578 so far.
TOI-2578 b — Complete Data
| Radius | 19.661 Earth radii (1.754 Jupiter radii) |
|---|---|
| Mass | 167.18 Earth masses (0.526 Jupiter masses) |
| Density | 0.12 g/cm³ (Earth: 5.51) |
| Orbital period | 3.46 days |
| Orbital distance | 0.050 AU |
| Eccentricity | 0.098 |
| Equilibrium temperature | 1,778 K (1,505 °C) |
| Stellar irradiation | 1,667.00× Earth |
| Distance from Earth | 931.3 light-years (285.5 parsecs) |
| Constellation | Perseus |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2026 |
Data: NASA Exoplanet Archive, last updated 2026-07-30. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-2578 b
Is TOI-2578 b habitable?
No — TOI-2578 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-2578 b?
TOI-2578 b is about 931 light-years from Earth in the constellation Perseus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 16,390,880 years to get there.
How big is TOI-2578 b compared to Earth?
TOI-2578 b has 19.66 times the radius of Earth and about 167 times its mass.
How long is a year on TOI-2578 b?
One orbit around TOI-2578 takes 3.5 Earth days — short enough that 106 of its years would fit into one Earth year.
Explore TOI-2578 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.
