Moon and Leo

StarDate

The Moon goes face to face with the lion early tomorrow. At first light, Regulus, Leo’s brightest star, stands close to the lower right of the Moon. And a star in the lion’s mane is a little farther to the left of the Moon. It’s part of the curving pattern of stars known as the Sickle.

Algieba is about 125 light-years away. It’s the fourth-brightest star in the constellation. And like Regulus, there’s a lot more to it than meets the eye. It consists of two stars, plus one known planet.

The stars are separated by hundreds of times the distance from Earth to the Sun, so it takes centuries for them to orbit each other.

Both stars are giants – they’re much bigger and brighter than the Sun. That tells us that both stars are late in life. They’ve burned through the hydrogen fuel in their cores. Now, they may be burning the helium “ash” created by that process. That’s caused their outer layers to puff up.

The heavier star has one confirmed planet. It was discovered 15 years ago. A study last year said it’s at least 11 times the mass of Jupiter, the giant of our own solar system. That means it’s likely a big ball of gas, probably with a small core of rock and metal. The planet is a bit farther from the star than Earth is from the Sun. At that range, the top of its atmosphere should be hot and turbulent. But so far, there haven’t been any follow-up studies to tell us more about this giant planet in the lion’s mane.

Script by Damond Benningfield