Kepler-1990 c
Kepler-1990 c is a terrestrial planet orbiting Kepler-1990 in the constellation Cygnus. It lies about 1,281 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is Kepler-1990 c?
Kepler-1990 c has a radius of 0.98 times that of Earth.
Is Kepler-1990 c in the Habitable Zone?
Kepler-1990 c orbits inside the inner edge of the habitable zone of Kepler-1990. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-1990: 0.798–1.880 AU (conservative: 1.010–1.783 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-1990 c
The equilibrium temperature of Kepler-1990 c is about 1,170 K (897 °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 442 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on Kepler-1990 c — one full orbit around Kepler-1990 — lasts 4.07 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.050 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-1990 c Discovered?
Kepler-1990 c 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-1990 c?
Kepler-1990 c is 1,280.9 light-years (392.7 parsecs) from Earth. Light arriving here tonight left the planet about 1,281 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 22,543,840 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-1990 c scores 0.30, ranking #1,530 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-1990
Kepler-1990
- Surface temperature
- 5,751 K (Sun: 5,772 K)
- Mass
- 1.03 M☉
- Radius
- 1.07 R☉
The Kepler-1990 Planetary System
Kepler-1990 c is one of 2 known planets in the Kepler-1990 system. Its siblings:
- Kepler-1990 b (Sub Neptune)
Kepler-1990 c — Complete Data
| Radius | 0.980 Earth radii (0.087 Jupiter radii) |
|---|---|
| Orbital period | 4.07 days |
| Orbital distance | 0.050 AU |
| Equilibrium temperature | 1,170 K (897 °C) |
| Stellar irradiation | 442.08× Earth |
| Earth Similarity Index | 0.30 |
| Distance from Earth | 1,280.9 light-years (392.7 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-1990 c
Is Kepler-1990 c habitable?
No — Kepler-1990 c orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-1990 c?
Kepler-1990 c is about 1,281 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 22,543,840 years to get there.
How big is Kepler-1990 c compared to Earth?
Kepler-1990 c has 0.98 times the radius of Earth.
How long is a year on Kepler-1990 c?
One orbit around Kepler-1990 takes 4.1 Earth days — short enough that 90 of its years would fit into one Earth year.
Explore Kepler-1990 c in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
