The Ring Nebula (M57) is a famous example of a planetary nebula. It's located in the constellation Lyra and is easily visible with amateur telescopes. It's known for its distinctive ring-shaped appearance, which is actually a shell of gas and dust expelled by a dying star.

Here are some other notable examples of planetary nebulae:

* Helix Nebula (NGC 7293): Located in the constellation Aquarius, it's one of the closest planetary nebulae to Earth, and its intricate structure is visible in detail with powerful telescopes.

* Dumbbell Nebula (M27): Located in the constellation Vulpecula, it's a popular target for amateur astronomers due to its relatively bright and well-defined appearance.

* Cat's Eye Nebula (NGC 6543): Known for its complex and intricate structure, it's considered one of the most beautiful planetary nebulae.

* Eskimo Nebula (NGC 2392): Its nickname comes from its appearance in smaller telescopes, resembling a human face with a fur-lined hood.

These are just a few examples of the many beautiful and fascinating planetary nebulae that exist in our galaxy.