xi Aql b
xi Aql b is a cold gas giant orbiting the K0 III star xi Aql in the constellation Aquila. It lies about 183 light-years from Earth and was discovered in 2007 using the radial velocity method.
Is xi Aql b in the Habitable Zone?
xi Aql b orbits inside the inner edge of the habitable zone of xi Aql. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of xi Aql: 6.037–14.691 AU (conservative: 7.646–13.928 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 xi Aql b — one full orbit around xi Aql — lasts 137.0 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 0.625 AU — comparable to the inner Solar System. Its orbit is mildly elliptical (eccentricity 0.06).
How Was xi Aql b Discovered?
xi Aql b was discovered in 2007 using the radial velocity method, with observations from Okayama Astrophysical Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is xi Aql b?
xi Aql b is 183.3 light-years (56.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1843. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,226,080 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. xi Aql b scores 0.07, ranking #4,822 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: xi Aql
xi Aql
- Spectral type
- K0 III
- Surface temperature
- 4,841 K (Sun: 5,772 K)
- Mass
- 1.74 M☉
- Radius
- 10.86 R☉
- Luminosity
- 58.5396 L☉
Planetary System
xi Aql b is the only planet known to orbit xi Aql so far.
xi Aql b — Complete Data
| Mass (best estimate) | 616.90 Earth masses |
|---|---|
| Orbital period | 136.97 days |
| Orbital distance | 0.625 AU |
| Eccentricity | 0.059 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 183.3 light-years (56.2 parsecs) |
| Constellation | Aquila |
| Discovery method | Radial Velocity |
| Discovery facility | Okayama Astrophysical Observatory |
| Discovery year | 2007 |
Data: NASA Exoplanet Archive, last updated 2023-09-19. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About xi Aql b
Is xi Aql b habitable?
No — xi Aql b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is xi Aql b?
xi Aql b is about 183 light-years from Earth in the constellation Aquila. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,226,080 years to get there.
How long is a year on xi Aql b?
One orbit around xi Aql takes 137.0 Earth days.
Explore xi Aql b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
