TOI-2145 b
TOI-2145 b is a cold gas giant orbiting TOI-2145 in the constellation Hercules. It lies about 733 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-2145 b?
TOI-2145 b has a radius of 12.24 times that of Earth, or 1.09 times the radius of Jupiter. Its mass is 1,805 times that of Earth.
Is TOI-2145 b in the Habitable Zone?
TOI-2145 b orbits inside the inner edge of the habitable zone of TOI-2145. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-2145: 2.320–5.412 AU (conservative: 2.938–5.131 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-2145 b — one full orbit around TOI-2145 — lasts 10.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.112 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.21).
How Was TOI-2145 b Discovered?
TOI-2145 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-2145 b?
TOI-2145 b is 733.0 light-years (224.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1293. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 12,900,800 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-2145 b scores 0.08, ranking #4,783 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-2145
TOI-2145
- Surface temperature
- 6,206 K (Sun: 5,772 K)
- Mass
- 1.71 M☉
- Radius
- 2.75 R☉
- Age
- 1.6 billion years (Sun: 4.6)
Planetary System
TOI-2145 b is the only planet known to orbit TOI-2145 so far.
TOI-2145 b — Complete Data
| Radius | 12.240 Earth radii (1.092 Jupiter radii) |
|---|---|
| Mass | 1,805.27 Earth masses (5.680 Jupiter masses) |
| Orbital period | 10.26 days |
| Orbital distance | 0.112 AU |
| Eccentricity | 0.214 |
| Earth Similarity Index | 0.08 |
| Distance from Earth | 733.0 light-years (224.7 parsecs) |
| Constellation | Hercules |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2026-02-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-2145 b
Is TOI-2145 b habitable?
No — TOI-2145 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-2145 b?
TOI-2145 b is about 733 light-years from Earth in the constellation Hercules. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 12,900,800 years to get there.
How big is TOI-2145 b compared to Earth?
TOI-2145 b has 12.24 times the radius of Earth and about 1,805 times its mass.
How long is a year on TOI-2145 b?
One orbit around TOI-2145 takes 10.3 Earth days — short enough that 36 of its years would fit into one Earth year.
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