Denebola

The Moon cruises past the heart of the lion tonight. Regulus, the brightest star of Leo, stands above the Moon in early evening. The lion’s body trails off to the lower left of Regulus. It ends at the star Denebola — the tip of the lion’s tail. Denebola is almost twice as big and heavy as the Sun, and about a dozen times brighter. And it’s pretty young as stars go — about one-tenth as old as the Sun. Like a few other stars in its age and size range, Denebola is encircled by a broad disk of dust. Some of the tiny particles that make up the disk probably are left over from the cloud that gave birth to the star, while others may be debris from collisions between larger chunks of material — the size of asteroids or bigger. No one has detected planets amidst this debris. But astronomers have found gaps in the disk that could have been cleared out by the gravity of orbiting planets. If planets do exist, they probably formed as the dust grains stuck together to form bigger and bigger bodies —