Things are heating up for a planet that orbits the brightest star of Aries. The star is expanding to become a giant, so it’s pumping more energy into space. That will make temperatures extremely uncomfortable on the planet.

Hamal is at the end of its life. It’s converted the hydrogen in its core to helium. Now, it’s getting ready to fuse the helium to make other elements. That’s made the core hotter. And that’s caused the star’s outer layers to puff up – to more than a dozen times the diameter of the Sun. So Hamal is about 75 times brighter than the Sun.

Hamal has one known possible planet. It’s heavier than Jupiter, the giant of our own solar system. On average, the planet is about as far from Hamal as Earth is from the Sun – much closer in than Jupiter is. So every square foot of the planet’s surface receives dozens of times more energy than the same area on Jupiter does.

If the planet is a ball of gas like Jupiter, then the extra heat is causing its atmosphere to puff up – and causing a lot of it to stream away into space.

Over the next few million years, the planet will get even hotter, because Hamal will get even bigger. The extra energy may erode the planet’s atmosphere completely. On the other hand, the planet may spiral into the star. Either way, things are going to get much hotter for Hamal’s only known planet.

Look for Hamal in the east at nightfall, well to the left of the Moon.

Script by Damond Benningfield