Neptune-sized planet may be remnant core of a much larger planet.

Discovery made through the Disk Detective project could help the search for new planets.

When searching for extraterrestrial life, astronomers may want to look at planets with hydrogen-rich atmospheres.

New research expands the pool of habitable worlds to include super-Earths with hydrogen-rich atmospheres.

Has the Sun entered a stage of old age?

The exoplanet Fomalhaut-b likely never was, say astronomers. Their work suggests an expanding cloud of dust instead.

The first known comet to visit us from another star system has an unusual make-up.

"We don't only look at other planets to know what's out there. It's also a way for us to learn things about the planet that's under our own feet."

Astronomers have found an exoplanet more than twice the size of Earth to be potentially habitable, opening the search for life to planets significantly larger than Earth but smaller than Neptune.