TOI-4638.01
TOI-4638.01 is a mini-Neptune orbiting TOI-4638 in the constellation Pisces. It lies about 549 light-years from Earth and was discovered in 2024 using the transit method.
How Big Is TOI-4638.01?
TOI-4638.01 has a radius of 2.93 times that of Earth.
Is TOI-4638.01 in the Habitable Zone?
TOI-4638.01 orbits inside the inner edge of the habitable zone of TOI-4638. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-4638: 0.657–1.550 AU (conservative: 0.832–1.470 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 ›
Temperature on TOI-4638.01
TOI-4638.01 receives 87.81 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-4638.01 — one full orbit around TOI-4638 — lasts 10.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.093 AU — closer to its star than Mercury is to the Sun.
How Was TOI-4638.01 Discovered?
TOI-4638.01 was discovered in 2024 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-4638.01?
TOI-4638.01 is 548.8 light-years (168.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1478. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 9,658,880 years to make the journey.
The Host Star: TOI-4638
TOI-4638
- Surface temperature
- 5,700 K (Sun: 5,772 K)
- Mass
- 1.02 M☉
- Radius
- 0.90 R☉
Planetary System
TOI-4638.01 is the only planet known to orbit TOI-4638 so far.
TOI-4638.01 — Complete Data
| Radius | 2.933 Earth radii (0.262 Jupiter radii) |
|---|---|
| Orbital period | 10.28 days |
| Orbital distance | 0.093 AU |
| Stellar irradiation | 87.81× Earth |
| Distance from Earth | 548.8 light-years (168.2 parsecs) |
| Constellation | Pisces |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2024 |
Data: NASA Exoplanet Archive, last updated 2024-12-10. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-4638.01
Is TOI-4638.01 habitable?
No — TOI-4638.01 orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-4638.01?
TOI-4638.01 is about 549 light-years from Earth in the constellation Pisces. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 9,658,880 years to get there.
How big is TOI-4638.01 compared to Earth?
TOI-4638.01 has 2.93 times the radius of Earth.
How long is a year on TOI-4638.01?
One orbit around TOI-4638 takes 10.3 Earth days — short enough that 36 of its years would fit into one Earth year.
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