Howard Isaacson

Two planets around the star TOI-4495 perform a stumbling dance: while the inner one completes two laps, the outer manages just one. But the rhythm is off — the inner planet speeds up and slows down, like a partner stumbling in her steps. Using the transit method, watching as the planets briefly dim the star's light, astronomers weighed these worlds.

A world where a year lasts just one and a half Earth days, and the star in its sky is hundreds of times larger than our Sun. This is KELT-9 b — a gas giant heated to temperatures at which iron vaporizes. Its atmosphere is not just hot; it is literally boiling away into space, like steam rising from a giant cauldron.

The family album of this stellar pair has been filling up for 45 years, but the pictures were blurry and the captions contradictory. Now astronomers have pulled out the old photographs, taken new sharp shots, and put everyone back in their proper places. Gamma Cephei is a bright star visible to the naked eye, and it has an invisible companion that orbits it every 70 years.