Kepler-619 d
Kepler-619 d is a Neptune-like planet orbiting Kepler-619 in the constellation Cygnus. It lies about 2,938 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is Kepler-619 d?
Kepler-619 d has a radius of 4.17 times that of Earth.
Is Kepler-619 d in the Habitable Zone?
Kepler-619 d orbits inside the inner edge of the habitable zone of Kepler-619. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-619: 0.795–1.859 AU (conservative: 1.007–1.762 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 Kepler-619 d
The equilibrium temperature of Kepler-619 d is about 830 K (557 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 112 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-619 d — one full orbit around Kepler-619 — lasts 11.7 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.102 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-619 d Discovered?
Kepler-619 d was discovered in 2023 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-619 d?
Kepler-619 d is 2,937.6 light-years (900.7 parsecs) from Earth. Light arriving here tonight left the planet about 2,938 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 51,701,760 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-619 d scores 0.18, ranking #4,015 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-619
Kepler-619
- Surface temperature
- 6,122 K (Sun: 5,772 K)
- Mass
- 1.04 M☉
- Radius
- 0.96 R☉
The Kepler-619 Planetary System
Kepler-619 d is one of 3 known planets in the Kepler-619 system. Its siblings:
- Kepler-619 b (Sub Neptune)
- Kepler-619 c (Super Earth)
Kepler-619 d — Complete Data
| Radius | 4.170 Earth radii (0.372 Jupiter radii) |
|---|---|
| Orbital period | 11.68 days |
| Orbital distance | 0.102 AU |
| Equilibrium temperature | 830 K (557 °C) |
| Stellar irradiation | 112.07× Earth |
| Earth Similarity Index | 0.18 |
| Distance from Earth | 2,937.6 light-years (900.7 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2017-05-08. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-619 d
Is Kepler-619 d habitable?
No — Kepler-619 d orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-619 d?
Kepler-619 d is about 2,938 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 51,701,760 years to get there.
How big is Kepler-619 d compared to Earth?
Kepler-619 d has 4.17 times the radius of Earth.
How long is a year on Kepler-619 d?
One orbit around Kepler-619 takes 11.7 Earth days — short enough that 31 of its years would fit into one Earth year.
Explore Kepler-619 d in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
