Confirmed exoplanet · Database record + computed analysis
XO-3 b
A confirmed world orbiting XO-3, 694.9 light-years away.
A gas giant
14.80 Earth radii, Jupiter-class (Jupiter is 11.2). With 4217.6 Earth masses packed into that size, its density points to rock and iron rather than gas. Orbiting this close, it is a classic 'hot Jupiter', a giant that migrated inward from where it formed.
The orbit
Its year, one full orbit, takes just 3.2 Earth days.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 1,617 °C. Hot enough to melt copper; any surface would glow. It receives 1,161.7 times the starlight Earth gets.
Its sun
Its star is hotter than the Sun (6,970 K, F5V), burning brighter and faster.
How far is that, really?
At 695 light-years, tonight's light from this system left it around the year 1331. A Voyager-speed probe would need roughly 12,294,334 years to get there.
How we found it
It was found by the transit method: the planet crosses its star's face on schedule, dimming it by a tiny, repeating fraction. The dip's depth gives the planet's size. The discovery was announced in 2007 from XO.
Everything above is computed from the archive’s measured values for this planet. Where a quantity is missing, the statement is omitted rather than guessed.
About this record
The measured values come from the NASA Exoplanet Archive, and any missing value has not been determined yet; the Atlas never fills gaps with guesses. More standout worlds: Proxima b, TRAPPIST-1e, K2-18 b, 55 Cancri e, and the detection methods that found them all.