TOI-921 b
TOI-921 b is a sub-Neptune orbiting TOI-921 in the constellation Carina. It lies about 959 light-years from Earth and was discovered in 2026 using the transit method.
How Big Is TOI-921 b?
TOI-921 b has a radius of 3.53 times that of Earth.
Is TOI-921 b in the Habitable Zone?
The position of TOI-921 b relative to the habitable zone of TOI-921 cannot be precisely determined from the available orbital data.
Habitable zone of TOI-921: 0.914–2.142 AU (conservative: 1.158–2.031 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-921 b — one full orbit around TOI-921 — lasts 5.13 Earth days, shorter than Mercury's 88-day year.
How Was TOI-921 b Discovered?
TOI-921 b was discovered in 2026 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-921 b?
TOI-921 b is 958.9 light-years (294.0 parsecs) from Earth. Light arriving here tonight left the planet around the year 1068. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 16,876,640 years to make the journey.
The Host Star: TOI-921
TOI-921
- Surface temperature
- 6,012 K (Sun: 5,772 K)
- Radius
- 1.14 R☉
Planetary System
TOI-921 b is the only planet known to orbit TOI-921 so far.
TOI-921 b — Complete Data
| Radius | 3.534 Earth radii (0.315 Jupiter radii) |
|---|---|
| Orbital period | 5.13 days |
| Distance from Earth | 958.9 light-years (294.0 parsecs) |
| Constellation | Carina |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2026 |
Data: NASA Exoplanet Archive, last updated 2026-04-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-921 b
Is TOI-921 b habitable?
TOI-921 b is not known to orbit within the habitable zone of TOI-921, and as a sub-Neptune it is an unlikely candidate for life as we know it.
How far away is TOI-921 b?
TOI-921 b is about 959 light-years from Earth in the constellation Carina. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 16,876,640 years to get there.
How big is TOI-921 b compared to Earth?
TOI-921 b has 3.53 times the radius of Earth.
How long is a year on TOI-921 b?
One orbit around TOI-921 takes 5.1 Earth days — short enough that 71 of its years would fit into one Earth year.
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