Observer's Notes: The Helix Nebula (NGC 7293) in Aquarius is an elusive object. To observe it, we would recommend at least a 6-inch telescope and a very dark sky. A nebula or deep-sky filter makes a world of difference. Part of the reason it is hard to observe is its size (roughly the same apparent diameter as the full moon). Its light is spread over a large area, making it dim overall. The Helix Nebula holds the distinction of being the closest and largest (in apparent diameter) planetary nebula to Earth. It lies approximately 450 light years away in southern Aquarius.
Reference: SEDS Helix Nebula page