Kepler-16 b stands in the Codex as the first confirmed circumbinary planet that transits both of its stars — the real Tatooine world. A Saturn-density giant about 8.4 × Earth across and roughly 106 Earth masses, it orbits a K-dwarf and M-dwarf pair 245 light-years away once every 229 days. Its path sits near the outer edge of the system’s habitable zone, cool enough that liquid water is only a distant maybe beneath twin sunsets. Doyle and colleagues’ 2011 Science discovery overturned the old fear that binary stars shred planets before they form. This entry endures in the Galactic Codex as proof that worlds can thrive in the dance of two suns.
