A second planet might orbit the closest star to the sun, and astronomers think it's a super-Earth

· Proxima Centauri, the closest star to the sun, might have a second planet in its orbit, according to a new study.
· Astronomers think the planet, called Proxima c, is a super-Earth that formed far from the icy region where scientists think such worlds are born.
· But Proxima c might not exist at all. The researchers are...