Multiple stars

Researchers from University College London and the University of Potsdam, Germany have studied two most massive touching stars in a neighboring galaxy that will eventually turn into black holes and collide, sending ripples through space and time.

What was once thought to be just one star is actually two. What's more, the two stars are so close that they've broken a record for being the tightest ultracool binary system ever observed, revolving around each other in less than an Earth day.

Astronomers have discovered a batch of rapidly spinning stars that produce X-rays at more than 100 times the peak levels from our Sun. The stars, which spin so fast they've been squashed into pumpkin-like shapes, are thought to be the result of close binary systems where two sun-like stars merge.

European astronomers have discovered a planet slightly more massive than Earth, orbiting a star in the Alpha Centauri triple star system.