TOI-733 b
TOI-733 b is a super-Earth orbiting the G star TOI-733 in the constellation Vela. It lies about 245 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-733 b?
TOI-733 b has a radius of 1.99 times that of Earth. Its mass is 5.7 times that of Earth, giving it a density of 3.98 g/cm³ — between that of rocky and gaseous planets.
Is TOI-733 b in the Habitable Zone?
TOI-733 b orbits inside the inner edge of the habitable zone of TOI-733. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-733: 0.687–1.628 AU (conservative: 0.871–1.544 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-733 b
The equilibrium temperature of TOI-733 b is about 1,056 K (783 °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 207 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-733 b — one full orbit around TOI-733 — lasts 4.88 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.062 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.046).
How Was TOI-733 b Discovered?
TOI-733 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-733 b?
TOI-733 b is 245.3 light-years (75.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1781. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 4,317,280 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-733 b scores 0.26, ranking #2,835 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-733
TOI-733
- Spectral type
- G
- Surface temperature
- 5,585 K (Sun: 5,772 K)
- Mass
- 0.96 M☉
- Radius
- 0.95 R☉
- Luminosity
- 0.8200 L☉
- Age
- 4.4 billion years (Sun: 4.6)
Planetary System
TOI-733 b is the only planet known to orbit TOI-733 so far.
TOI-733 b — Complete Data
| Radius | 1.992 Earth radii (0.178 Jupiter radii) |
|---|---|
| Mass | 5.72 Earth masses (0.018 Jupiter masses) |
| Density | 3.98 g/cm³ (Earth: 5.51) |
| Orbital period | 4.88 days |
| Orbital distance | 0.062 AU |
| Eccentricity | 0.046 |
| Equilibrium temperature | 1,056 K (783 °C) |
| Stellar irradiation | 207.10× Earth |
| Earth Similarity Index | 0.26 |
| Distance from Earth | 245.3 light-years (75.2 parsecs) |
| Constellation | Vela |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-04-17. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-733 b
Is TOI-733 b habitable?
No — TOI-733 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-733 b?
TOI-733 b is about 245 light-years from Earth in the constellation Vela. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 4,317,280 years to get there.
How big is TOI-733 b compared to Earth?
TOI-733 b has 1.99 times the radius of Earth and about 5.7 times its mass.
How long is a year on TOI-733 b?
One orbit around TOI-733 takes 4.9 Earth days — short enough that 75 of its years would fit into one Earth year.
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