Kepler-174 d
Kepler-174 d is a mini-Neptune orbiting Kepler-174 in the constellation Lyra. It lies about 1,255 light-years from Earth and was discovered in 2014 using the transit method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
How Big Is Kepler-174 d?
Kepler-174 d has a radius of 2.19 times that of Earth.
Is Kepler-174 d in the Habitable Zone?
Kepler-174 d orbits inside the conservative habitable zone of Kepler-174 — the region where a rocky planet could sustain liquid water on its surface. This makes it one of the most interesting known exoplanets in the search for life.
Habitable zone of Kepler-174: 0.349–0.849 AU (conservative: 0.443–0.805 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 Kepler-174 d — one full orbit around Kepler-174 — lasts 247.4 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 0.677 AU — comparable to the inner Solar System.
How Was Kepler-174 d Discovered?
Kepler-174 d was discovered in 2014 using the transit method, with observations from Kepler.
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 Kepler-174 d?
Kepler-174 d is 1,254.9 light-years (384.8 parsecs) from Earth. Light arriving here tonight left the planet about 1,255 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 22,086,240 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. Kepler-174 d scores 0.68, ranking #73 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-174
Kepler-174
- Surface temperature
- 4,880 K (Sun: 5,772 K)
- Radius
- 0.62 R☉
The Kepler-174 Planetary System
Kepler-174 d is one of 3 known planets in the Kepler-174 system. Its siblings:
- Kepler-174 b (Super Earth)
- Kepler-174 c (Super Earth)
Kepler-174 d — Complete Data
| Radius | 2.190 Earth radii (0.195 Jupiter radii) |
|---|---|
| Orbital period | 247.35 days |
| Orbital distance | 0.677 AU |
| Earth Similarity Index | 0.68 |
| Distance from Earth | 1,254.9 light-years (384.8 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2014 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-174 d
Is Kepler-174 d habitable?
Kepler-174 d orbits within the habitable zone of Kepler-174, the region where liquid water could exist on a planet's surface. It sits in the conservative habitable zone — the most promising region for habitability. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is Kepler-174 d?
Kepler-174 d is about 1,255 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 22,086,240 years to get there.
How big is Kepler-174 d compared to Earth?
Kepler-174 d has 2.19 times the radius of Earth.
How long is a year on Kepler-174 d?
One orbit around Kepler-174 takes 247.4 Earth days.
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