The engine powering the Pacman Nebula is an open star cluster called IC 1590. It’s in the centre of the nebula, and contains just shy of 300 stars. You can see quite a few of them in my image.

These stars are about 3.5 million years old, which is young as stars go. They’re O and B type, which means they’re very hot and have a high mass. They’re also emitting intense ultraviolet radiation, which is ionising the surrounding gas and making it glow. If the Pacman Nebula didn’t have IC 1590 within it, then it would be a dark nebula instead (like the Seahorse Nebula).

The picture below is a tight crop of IC1590, and I’ve inverted the colours so the stars stand out more.

The dark “mouth” of Pacman isn’t empty space, but rather a dense complex of cold gas and dust that’s in front of the nebula, as seen from our perspective on Earth. It’s blocking the glowing gas behind it, making a silhouette. It’s being slowly eroded away, and may not be there at all in another few hundred thousand years.

There are some interesting looking Bok globules in my image — small, cold, dense clumps of gas and dust that are the shrouds of newly-forming stars. They feature in my Cygnus Wall write-up. One of the Bok globules objects I’ve captured (right in the middle of my main picture) has been imaged by the Hubble Space Telescope. Use the slider view below to compare. It really shows off Hubble’s resolution!