K2-409 b
K2-409 b is a mini-Neptune orbiting K2-409 in the constellation Libra. It lies about 1,406 light-years from Earth and was discovered in 2022 using the transit method.
How Big Is K2-409 b?
K2-409 b has a radius of 2.48 times that of Earth.
Is K2-409 b in the Habitable Zone?
The position of K2-409 b relative to the habitable zone of K2-409 cannot be precisely determined from the available orbital data.
Habitable zone of K2-409: 0.912–2.151 AU (conservative: 1.155–2.039 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 K2-409 b — one full orbit around K2-409 — lasts just 45.8 hours, shorter than Mercury's 88-day year.
How Was K2-409 b Discovered?
K2-409 b was discovered in 2022 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 K2-409 b?
K2-409 b is 1,405.8 light-years (431.0 parsecs) from Earth. Light arriving here tonight left the planet about 1,406 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 24,742,080 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. K2-409 b scores 0.23, ranking #3,475 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-409
K2-409
- Surface temperature
- 5,742 K (Sun: 5,772 K)
- Mass
- 0.89 M☉
- Radius
- 1.23 R☉
Planetary System
K2-409 b is the only planet known to orbit K2-409 so far.
K2-409 b — Complete Data
| Radius | 2.482 Earth radii (0.221 Jupiter radii) |
|---|---|
| Orbital period | 1.91 days |
| Earth Similarity Index | 0.23 |
| Distance from Earth | 1,405.8 light-years (431.0 parsecs) |
| Constellation | Libra |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-03-16. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-409 b
Is K2-409 b habitable?
K2-409 b is not known to orbit within the habitable zone of K2-409, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is K2-409 b?
K2-409 b is about 1,406 light-years from Earth in the constellation Libra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 24,742,080 years to get there.
How big is K2-409 b compared to Earth?
K2-409 b has 2.48 times the radius of Earth.
How long is a year on K2-409 b?
One orbit around K2-409 takes 1.9 Earth days — short enough that 191 of its years would fit into one Earth year.
Explore K2-409 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
