Astronomers have discovered thousands of planets in other star systems. You might think they’d have found many of them in clusters — places where hundreds of stars are close together. That’s not the case, though. The clusters are so tightly packed that it’s hard to isolate individual stars and find their planets.
One cluster where planets have been found is M44, the Beehive. It contains a thousand stars, all packed into a region only a few dozen light-years across.
The first planets in the cluster were discovered in 2012. One of them is about half as massive as Jupiter, the giant of our own solar system. It’s quite close to its star, though, so it’s much hotter than Jupiter.
A similar planet was discovered around a second star in the cluster. And another planet was found in the same system a few years later. It’s much heavier than Jupiter. It’s about the same distance out as Jupiter is from the Sun, though, so it’s much cooler than its planetary sibling.
Two more planets were found orbiting a third star a couple of years ago. Both of them are between the size of Earth and Neptune, the Sun’s fourth-largest planet. And both are close in, so they, too, are hot — rare finds in a busy star cluster.
The Beehive is low in the west-northwest as night falls now. It’s a little easier to spot tonight because it’s near the crescent Moon. Binoculars will reveal a swarm of stars close to the lower left of the Moon.
Script by Damond Benningfield