Charles Q. Choi

Astronomers are searching for gravitational waves possibly emitted by "strange stars," superdense objects made of exotic matter.

Binary Earth-size planets that orbit each other might exist around distant stars, researchers say. Simulations suggest such worlds can begin circling each other after slow, grazing collisions.

The mysterious substance that makes up most of the matter in the universe may be destroying neutron stars by turning them into black holes in the center of the Milky Way, new research suggests.

The mysterious dark matter that makes up most of the matter in the universe may behave more like wavy fluids than solid particles, helping to explain the shapes of galaxies, a new study suggests.

A planet may be forming in a star system with more than one sun, making it sort of like an early Tatooine, the fictional home world of Luke Skywalker in "Star Wars," new research shows.

Gravitational waves, invisible ripples in the fabric of space and time, might be detected by looking for the brightening of stars, researchers say.

After a 40-year search, astronomers have apparently found the first Thorne-Zytkow object, a hypothesized hybrid star thought to form when a red supergiant swallows a neutron star.

Astronomers have found that a small, nearby galaxy may harbor a giant secret — a supermassive black hole at its heart equal in mass to about 21 million suns.

Scientists may have solved the mystery behind why giant hot Jupiter planets have such weird orbits. As these giant worlds drew close to their stars, they may force the stars into a chaotic wobble.

A new cosmic map is giving scientists an unprecedented look at the boundaries for the giant supercluster that is home to Earth's own Milky Way galaxy and many others.

Supernovas may spark from catastrophic nuclear explosions on dead white dwarfs. The scenario has long been theorized by scientists, but now direct evidence has been found.

Seven tiny grains of rock captured by NASA's comet-chasing Stardust probe in 2004 may be visitors from the vast reaches of interstellar space, researchers say.