TOI-1736 b
TOI-1736 b is a sub-Neptune orbiting TOI-1736 in the constellation Cassiopeia. It lies about 290 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-1736 b?
TOI-1736 b has a radius of 3.18 times that of Earth. Its mass is 12.3 times that of Earth, giving it a density of 2.09 g/cm³ — between that of rocky and gaseous planets.
Is TOI-1736 b in the Habitable Zone?
TOI-1736 b orbits inside the inner edge of the habitable zone of TOI-1736. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-1736: 1.034–2.445 AU (conservative: 1.309–2.318 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-1736 b
The equilibrium temperature of TOI-1736 b is about 1,100 K (827 °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-1736 b — one full orbit around TOI-1736 — lasts 7.07 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.073 AU — closer to its star than Mercury is to the Sun.
How Was TOI-1736 b Discovered?
TOI-1736 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-1736 b?
TOI-1736 b is 290.1 light-years (88.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1736. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 5,105,760 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-1736 b scores 0.24, ranking #3,374 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1736
TOI-1736
- Surface temperature
- 5,636 K (Sun: 5,772 K)
- Mass
- 1.04 M☉
- Radius
- 1.43 R☉
- Luminosity
- 1.8650 L☉
- Age
- 9.2 billion years (Sun: 4.6)
The TOI-1736 Planetary System
TOI-1736 b is one of 2 known planets in the TOI-1736 system. Its siblings:
- TOI-1736 c (Cold Gas Giant)
TOI-1736 b — Complete Data
| Radius | 3.182 Earth radii (0.284 Jupiter radii) |
|---|---|
| Mass | 12.30 Earth masses (0.039 Jupiter masses) |
| Density | 2.09 g/cm³ (Earth: 5.51) |
| Orbital period | 7.07 days |
| Orbital distance | 0.073 AU |
| Equilibrium temperature | 1,100 K (827 °C) |
| Earth Similarity Index | 0.24 |
| Distance from Earth | 290.1 light-years (88.9 parsecs) |
| Constellation | Cassiopeia |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2024-07-22. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1736 b
Is TOI-1736 b habitable?
No — TOI-1736 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-1736 b?
TOI-1736 b is about 290 light-years from Earth in the constellation Cassiopeia. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 5,105,760 years to get there.
How big is TOI-1736 b compared to Earth?
TOI-1736 b has 3.18 times the radius of Earth and about 12.3 times its mass.
How long is a year on TOI-1736 b?
One orbit around TOI-1736 takes 7.1 Earth days — short enough that 52 of its years would fit into one Earth year.
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