The XO-4 system contains 1 exoplanet. It is located 889.28 light years away from the solar system.
| Mass | 1.1 solar masses |
| Radius | 1.45 solar radiae |
| Temperature | 6397 kelvin |
| Stellar Metallicity | -0.04 decimal exponent |
| Age | 2.1 billion years |
At more than 50 Earth masses, XO-4 b is a gas giant, a planet whose mass is mostly made up of hydrogen and helium, like Jupiter and Saturn.
| Mass | 451.319 Earth masses |
| Density | 0.830 grams per cubic centimeter |
| Radius | 14.011 Earth radiae |
| Semi-major Axis | 0.05524 AU |
| Eccentricity | 0 |
| Orbital Period | 4.125 days |
| Discovery Method | Transit |
| Discovery Facility | XO |
| Discovery Telescope | Canon 200mm f/1.8L |
| Discovery Instrument | Apogee CCD Array |
| Discovery Date | 2008-05 |
| Reference | McCullogh et al. 2008 |