The weirdest binary: Planet and not-a-star barely orbit each other

Astronomers have found a pretty weird binary system about 450 light years from Earth: Neither of its components is a star. Instead, one is a brown dwarf, and the other appears to be a planet orbiting it! Even then, the brown dwarf is on the lower end of things. If it were any less massive it would be a planet itself.

The system is called CFHTWIR-Oph 98, but we'll call it Oph 98 for short. It was found a few years ago in ground-based observations using the Canada-France-Hawaii Telescope's infrar...