Kepler-1388 d
Kepler-1388 d is a mini-Neptune orbiting Kepler-1388 in the constellation Lyra. It lies about 1,480 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is Kepler-1388 d?
Kepler-1388 d has a radius of 2.86 times that of Earth.
Is Kepler-1388 d in the Habitable Zone?
The position of Kepler-1388 d relative to the habitable zone of Kepler-1388 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-1388: 0.248–0.625 AU (conservative: 0.315–0.593 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-1388 d — one full orbit around Kepler-1388 — lasts 21.0 Earth days, shorter than Mercury's 88-day year.
How Was Kepler-1388 d Discovered?
Kepler-1388 d was discovered in 2016 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-1388 d?
Kepler-1388 d is 1,480.1 light-years (453.8 parsecs) from Earth. Light arriving here tonight left the planet about 1,480 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 26,049,760 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-1388 d scores 0.42, ranking #414 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-1388
Kepler-1388
- Surface temperature
- 4,098 K (Sun: 5,772 K)
- Mass
- 0.63 M☉
- Radius
- 0.61 R☉
- Age
- 4.5 billion years (Sun: 4.6)
The Kepler-1388 Planetary System
Kepler-1388 d is one of 4 known planets in the Kepler-1388 system. Its siblings:
- Kepler-1388 b (Mini Neptune)
- Kepler-1388 c (Mini Neptune)
- Kepler-1388 e (Mini Neptune)
Kepler-1388 d — Complete Data
| Radius | 2.860 Earth radii (0.255 Jupiter radii) |
|---|---|
| Orbital period | 20.96 days |
| Earth Similarity Index | 0.42 |
| Distance from Earth | 1,480.1 light-years (453.8 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2016-05-06. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-1388 d
Is Kepler-1388 d habitable?
Kepler-1388 d is not known to orbit within the habitable zone of Kepler-1388, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is Kepler-1388 d?
Kepler-1388 d is about 1,480 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 26,049,760 years to get there.
How big is Kepler-1388 d compared to Earth?
Kepler-1388 d has 2.86 times the radius of Earth.
How long is a year on Kepler-1388 d?
One orbit around Kepler-1388 takes 21.0 Earth days — short enough that 17 of its years would fit into one Earth year.
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