TOI-1759 b
TOI-1759 b is a sub-Neptune orbiting the M0.0 V star TOI-1759 in the constellation Cepheus. It lies about 131 light-years from Earth and was discovered in 2022 using the transit method.
How Big Is TOI-1759 b?
TOI-1759 b has a radius of 3.14 times that of Earth. Its mass is 10.8 times that of Earth, giving it a density of 1.91 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-1759 b in the Habitable Zone?
TOI-1759 b orbits inside the inner edge of the habitable zone of TOI-1759. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-1759: 0.240–0.605 AU (conservative: 0.304–0.574 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-1759 b
The equilibrium temperature of TOI-1759 b is about 443 K (170 °C) — hotter than anywhere on Earth. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 6.39 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-1759 b — one full orbit around TOI-1759 — lasts 18.9 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.118 AU — closer to its star than Mercury is to the Sun.
How Was TOI-1759 b Discovered?
TOI-1759 b was discovered in 2022 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-1759 b?
TOI-1759 b is 130.7 light-years (40.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1896. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,300,320 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-1759 b scores 0.37, ranking #634 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1759
TOI-1759
- Spectral type
- M0.0 V
- Surface temperature
- 4,065 K (Sun: 5,772 K)
- Mass
- 0.61 M☉
- Radius
- 0.60 R☉
- Luminosity
- 0.0877 L☉
- Age
- 5.0 billion years (Sun: 4.6)
Planetary System
TOI-1759 b is the only planet known to orbit TOI-1759 so far.
TOI-1759 b — Complete Data
| Radius | 3.140 Earth radii (0.280 Jupiter radii) |
|---|---|
| Mass | 10.80 Earth masses (0.034 Jupiter masses) |
| Density | 1.91 g/cm³ (Earth: 5.51) |
| Orbital period | 18.85 days |
| Orbital distance | 0.118 AU |
| Equilibrium temperature | 443 K (170 °C) |
| Stellar irradiation | 6.39× Earth |
| Earth Similarity Index | 0.37 |
| Distance from Earth | 130.7 light-years (40.1 parsecs) |
| Constellation | Cepheus |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-03-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1759 b
Is TOI-1759 b habitable?
No — TOI-1759 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-1759 b?
TOI-1759 b is about 131 light-years from Earth in the constellation Cepheus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,300,320 years to get there.
How big is TOI-1759 b compared to Earth?
TOI-1759 b has 3.14 times the radius of Earth and about 10.8 times its mass.
How long is a year on TOI-1759 b?
One orbit around TOI-1759 takes 18.9 Earth days — short enough that 19 of its years would fit into one Earth year.
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