XO-2 S d
XO-2 S d is a cold gas giant orbiting the G8 V star XO-2 S in the constellation Lynx. It lies about 494 light-years from Earth and was discovered in 2024 using the radial velocity method.
Is XO-2 S d in the Habitable Zone?
XO-2 S d orbits beyond the outer edge of the habitable zone of XO-2 S. At that distance, any surface water would almost certainly be frozen.
Habitable zone of XO-2 S: 0.667–1.594 AU (conservative: 0.845–1.511 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 XO-2 S d — one full orbit around XO-2 S — lasts 4,696.0 Earth days, longer than Jupiter's 12-year orbit. It orbits at an average distance of 5.460 AU. Its orbit is mildly elliptical (eccentricity 0.09).
How Was XO-2 S d Discovered?
XO-2 S d was discovered in 2024 using the radial velocity method, with observations from Multiple Observatories.
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 XO-2 S d?
XO-2 S d is 493.8 light-years (151.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1533. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 8,690,880 years to make the journey.
The Host Star: XO-2 S
XO-2 S d belongs to a system of 2 stars; it orbits XO-2 S.
XO-2 S
- Spectral type
- G8 V
- Surface temperature
- 5,325 K (Sun: 5,772 K)
- Mass
- 0.98 M☉
- Radius
- 1.02 R☉
The XO-2 S Planetary System
XO-2 S d is one of 3 known planets in the XO-2 S system. Its siblings:
XO-2 S d — Complete Data
| Mass (best estimate) | 1,179.14 Earth masses |
|---|---|
| Orbital period | 4,696.00 days |
| Orbital distance | 5.460 AU |
| Eccentricity | 0.091 |
| Distance from Earth | 493.8 light-years (151.4 parsecs) |
| Constellation | Lynx |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2024 |
Data: NASA Exoplanet Archive, last updated 2026-05-21. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About XO-2 S d
Is XO-2 S d habitable?
No — XO-2 S d orbits outside the habitable zone of XO-2 S and is likely too cold for liquid water on its surface.
How far away is XO-2 S d?
XO-2 S d is about 494 light-years from Earth in the constellation Lynx. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 8,690,880 years to get there.
How long is a year on XO-2 S d?
One orbit around XO-2 S takes 4,696.0 Earth days.
Explore XO-2 S 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.
