TOI-4377 b
TOI-4377 b is a hot Jupiter orbiting TOI-4377 in the constellation Chamaeleon. It lies about 1,487 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-4377 b?
TOI-4377 b has a radius of 15.11 times that of Earth, or 1.35 times the radius of Jupiter. Its mass is 304 times that of Earth, giving it a density of 0.88 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-4377 b in the Habitable Zone?
TOI-4377 b orbits inside the inner edge of the habitable zone of TOI-4377. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-4377: 2.021–4.891 AU (conservative: 2.560–4.637 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 ›
Orbit and Year Length
A year on TOI-4377 b — one full orbit around TOI-4377 — lasts 4.38 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.058 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.045).
How Was TOI-4377 b Discovered?
TOI-4377 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-4377 b?
TOI-4377 b is 1,486.7 light-years (455.8 parsecs) from Earth. Light arriving here tonight left the planet about 1,487 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 26,165,920 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-4377 b scores 0.06, ranking #5,140 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-4377
TOI-4377
- Surface temperature
- 4,974 K (Sun: 5,772 K)
- Mass
- 1.36 M☉
- Radius
- 3.52 R☉
- Luminosity
- 6.6400 L☉
- Age
- 3.9 billion years (Sun: 4.6)
Planetary System
TOI-4377 b is the only planet known to orbit TOI-4377 so far.
TOI-4377 b — Complete Data
| Radius | 15.110 Earth radii (1.348 Jupiter radii) |
|---|---|
| Mass | 304.16 Earth masses (0.957 Jupiter masses) |
| Density | 0.88 g/cm³ (Earth: 5.51) |
| Orbital period | 4.38 days |
| Orbital distance | 0.058 AU |
| Eccentricity | 0.045 |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 1,486.7 light-years (455.8 parsecs) |
| Constellation | Chamaeleon |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-11-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-4377 b
Is TOI-4377 b habitable?
No — TOI-4377 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-4377 b?
TOI-4377 b is about 1,487 light-years from Earth in the constellation Chamaeleon. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 26,165,920 years to get there.
How big is TOI-4377 b compared to Earth?
TOI-4377 b has 15.11 times the radius of Earth and about 304 times its mass.
How long is a year on TOI-4377 b?
One orbit around TOI-4377 takes 4.4 Earth days — short enough that 83 of its years would fit into one Earth year.
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