Abell 39 is a large, very faint, spherical, blue-green planetary nebula in Hercules.

It is 2.9 arcminutes in diameter and shines at magnitude 13.7. Because it is so large, it has a low surface brightness which makes it hard to observe or photograph.

Abell 39 is located 7,000 light-years away, and its true size in space is 5 light-years in diameter. It is thought to be 22,000 years old.

Abell 39 was cataloged by George Abell in his catalogs of planetary nebulae published in 1955 and 1966.

North is to the top in the above image.

Abell 39 Catalogs: Abell 39, PK 47+42.1 Object Type: Planetary Nebula Magnitude: 13.7v Size: 2.9' Constellation: Hercules Image Field Centered At: RA: 16h 27m 34s Dec: +27° 54' 47"