K2-354 b
K2-354 b is a super-Earth orbiting K2-354 in the constellation Cancer. It lies about 299 light-years from Earth and was discovered in 2021 using the transit method.
How Big Is K2-354 b?
K2-354 b has a radius of 1.56 times that of Earth.
Is K2-354 b in the Habitable Zone?
The position of K2-354 b relative to the habitable zone of K2-354 cannot be precisely determined from the available orbital data.
Habitable zone of K2-354: 0.135–0.347 AU (conservative: 0.171–0.329 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 K2-354 b
The equilibrium temperature of K2-354 b is about 543 K (270 °C) — hotter than anywhere on Earth. 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 K2-354 b — one full orbit around K2-354 — lasts 3.79 Earth days, shorter than Mercury's 88-day year.
How Was K2-354 b Discovered?
K2-354 b was discovered in 2021 using the transit method, with observations from K2.
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 K2-354 b?
K2-354 b is 299.2 light-years (91.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1727. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 5,265,920 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. K2-354 b scores 0.35, ranking #796 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-354
K2-354
- Surface temperature
- 3,669 K (Sun: 5,772 K)
- Mass
- 0.43 M☉
- Radius
- 0.41 R☉
Planetary System
K2-354 b is the only planet known to orbit K2-354 so far.
K2-354 b — Complete Data
| Radius | 1.560 Earth radii (0.139 Jupiter radii) |
|---|---|
| Orbital period | 3.79 days |
| Equilibrium temperature | 543 K (270 °C) |
| Earth Similarity Index | 0.35 |
| Distance from Earth | 299.2 light-years (91.7 parsecs) |
| Constellation | Cancer |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2021-08-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-354 b
Is K2-354 b habitable?
K2-354 b is not known to orbit within the habitable zone of K2-354, and as a super-Earth it is an unlikely candidate for life as we know it.
How far away is K2-354 b?
K2-354 b is about 299 light-years from Earth in the constellation Cancer. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 5,265,920 years to get there.
How big is K2-354 b compared to Earth?
K2-354 b has 1.56 times the radius of Earth.
How long is a year on K2-354 b?
One orbit around K2-354 takes 3.8 Earth days — short enough that 96 of its years would fit into one Earth year.
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