K2-19 b
K2-19 b is a hot Jupiter orbiting K2-19 in the constellation Virgo. It lies about 945 light-years from Earth and was discovered in 2015 using the transit method.
How Big Is K2-19 b?
K2-19 b has a radius of 7.00 times that of Earth, or 0.62 times the radius of Jupiter. Its mass is 30.8 times that of Earth, giving it a density of 0.49 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is K2-19 b in the Habitable Zone?
The position of K2-19 b relative to the habitable zone of K2-19 cannot be precisely determined from the available orbital data.
Habitable zone of K2-19: 0.536–1.280 AU (conservative: 0.679–1.214 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 K2-19 b — one full orbit around K2-19 — lasts 7.92 Earth days, shorter than Mercury's 88-day year. Its orbit is mildly elliptical (eccentricity 0.10).
How Was K2-19 b Discovered?
K2-19 b was discovered in 2015 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 K2-19 b?
K2-19 b is 945.3 light-years (289.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1081. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 16,637,280 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. K2-19 b scores 0.13, ranking #4,296 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-19
K2-19
- Surface temperature
- 5,322 K (Sun: 5,772 K)
- Mass
- 0.88 M☉
- Radius
- 0.82 R☉
The K2-19 Planetary System
K2-19 b is one of 3 known planets in the K2-19 system. Its siblings:
K2-19 b — Complete Data
| Radius | 7.000 Earth radii (0.624 Jupiter radii) |
|---|---|
| Mass | 30.80 Earth masses (0.097 Jupiter masses) |
| Density | 0.49 g/cm³ (Earth: 5.51) |
| Orbital period | 7.92 days |
| Eccentricity | 0.100 |
| Earth Similarity Index | 0.13 |
| Distance from Earth | 945.3 light-years (289.8 parsecs) |
| Constellation | Virgo |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2015 |
Data: NASA Exoplanet Archive, last updated 2026-04-30. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-19 b
Is K2-19 b habitable?
K2-19 b is not known to orbit within the habitable zone of K2-19, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is K2-19 b?
K2-19 b is about 945 light-years from Earth in the constellation Virgo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 16,637,280 years to get there.
How big is K2-19 b compared to Earth?
K2-19 b has 7.00 times the radius of Earth and about 30.8 times its mass.
How long is a year on K2-19 b?
One orbit around K2-19 takes 7.9 Earth days — short enough that 46 of its years would fit into one Earth year.