TOI-4940 b
TOI-4940 b is a cold gas giant orbiting the G8 V star TOI-4940 in the constellation Reticulum. It lies about 1,127 light-years from Earth and was discovered in 2025 using the transit method.
How Big Is TOI-4940 b?
TOI-4940 b has a radius of 6.61 times that of Earth, or 0.59 times the radius of Jupiter. Its mass is 89.0 times that of Earth.
Is TOI-4940 b in the Habitable Zone?
TOI-4940 b orbits inside the inner edge of the habitable zone of TOI-4940. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-4940: 0.806–1.913 AU (conservative: 1.020–1.814 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-4940 b
The equilibrium temperature of TOI-4940 b is about 643 K (370 °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-4940 b — one full orbit around TOI-4940 — lasts 25.9 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.165 AU — closer to its star than Mercury is to the Sun.
How Was TOI-4940 b Discovered?
TOI-4940 b was discovered in 2025 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-4940 b?
TOI-4940 b is 1,127.4 light-years (345.7 parsecs) from Earth. Light arriving here tonight left the planet about 1,127 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 19,842,240 years to make the journey.
The Host Star: TOI-4940
TOI-4940
- Spectral type
- G8 V
- Surface temperature
- 5,504 K (Sun: 5,772 K)
- Mass
- 1.01 M☉
- Radius
- 1.16 R☉
- Luminosity
- 1.1160 L☉
- Age
- 9.8 billion years (Sun: 4.6)
Planetary System
TOI-4940 b is the only planet known to orbit TOI-4940 so far.
TOI-4940 b — Complete Data
| Radius | 6.610 Earth radii (0.590 Jupiter radii) |
|---|---|
| Mass | 89.00 Earth masses (0.280 Jupiter masses) |
| Orbital period | 25.87 days |
| Orbital distance | 0.165 AU |
| Equilibrium temperature | 643 K (370 °C) |
| Distance from Earth | 1,127.4 light-years (345.7 parsecs) |
| Constellation | Reticulum |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2026-01-15. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-4940 b
Is TOI-4940 b habitable?
No — TOI-4940 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-4940 b?
TOI-4940 b is about 1,127 light-years from Earth in the constellation Reticulum. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 19,842,240 years to get there.
How big is TOI-4940 b compared to Earth?
TOI-4940 b has 6.61 times the radius of Earth and about 89.0 times its mass.
How long is a year on TOI-4940 b?
One orbit around TOI-4940 takes 25.9 Earth days — short enough that 14 of its years would fit into one Earth year.
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