TOI-640 b
TOI-640 b is a hot Jupiter orbiting TOI-640 in the constellation Columba. It lies about 1,115 light-years from Earth and was discovered in 2021 using the transit method.
How Big Is TOI-640 b?
TOI-640 b has a radius of 19.28 times that of Earth, or 1.72 times the radius of Jupiter. Its mass is 181 times that of Earth, giving it a density of 0.14 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-640 b in the Habitable Zone?
The position of TOI-640 b relative to the habitable zone of TOI-640 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-640: 1.874–4.353 AU (conservative: 2.374–4.127 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-640 b
The equilibrium temperature of TOI-640 b is about 1,816 K (1,543 °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-640 b — one full orbit around TOI-640 — lasts 5.00 Earth days, shorter than Mercury's 88-day year. Its orbit is nearly circular (eccentricity 0.013).
How Was TOI-640 b Discovered?
TOI-640 b was discovered in 2021 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-640 b?
TOI-640 b is 1,115.4 light-years (342.0 parsecs) from Earth. Light arriving here tonight left the planet about 1,115 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 19,631,040 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-640 b scores 0.05, ranking #5,300 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-640
TOI-640
- Surface temperature
- 6,460 K (Sun: 5,772 K)
- Mass
- 1.54 M☉
- Radius
- 2.08 R☉
- Age
- 2.0 billion years (Sun: 4.6)
Planetary System
TOI-640 b is the only planet known to orbit TOI-640 so far.
TOI-640 b — Complete Data
| Radius | 19.279 Earth radii (1.720 Jupiter radii) |
|---|---|
| Mass | 181.16 Earth masses (0.570 Jupiter masses) |
| Density | 0.14 g/cm³ (Earth: 5.51) |
| Orbital period | 5.00 days |
| Eccentricity | 0.013 |
| Equilibrium temperature | 1,816 K (1,543 °C) |
| Earth Similarity Index | 0.05 |
| Distance from Earth | 1,115.4 light-years (342.0 parsecs) |
| Constellation | Columba |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2025-03-21. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-640 b
Is TOI-640 b habitable?
TOI-640 b is not known to orbit within the habitable zone of TOI-640, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is TOI-640 b?
TOI-640 b is about 1,115 light-years from Earth in the constellation Columba. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 19,631,040 years to get there.
How big is TOI-640 b compared to Earth?
TOI-640 b has 19.28 times the radius of Earth and about 181 times its mass.
How long is a year on TOI-640 b?
One orbit around TOI-640 takes 5.0 Earth days — short enough that 73 of its years would fit into one Earth year.
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