What is a Planetary Nebula?

This unfortunate name has nothing to do with planets.  Early astronomers with primitive equipment noticed deep space objects that with often small, bright, and round which looked like planets. This is how they got their name.  In reality they are shells of gas blown off by intermediate sized-stars (like our Sun) late in life.  Planetary nebula are usually circular in shape and  brighter ones often feature red and green colors.

Good examples of planetary nebula include the Ring nebula (M57), the Dumbbell nebula (M27) and the Owl nebula (M97).

Dumbell Nebula M27

Dumbell Nebula M27

TEC140ED Refractor

NGC7009 The Saturn Nebula

NGC7009 The Saturn Nebula

TEC140ED Refractor

Helix Nebula NGC7293

Celestron C9.25/Hyperstar

Medusa Nebula

TEC 140 ED APO

M97 Owl Nebula

M97 Owl Nebula

TEC140ED Refractor

Cats Eye Nebula

Cats Eye Nebula

Remote CDK24 in Chile

Jones Emberton 1

TEC 160FL APO

NGC 1501 Oyster Nebula

NGC 1501 Oyster Nebula

TEC 160FL APO

Cats Eye Nebula

TEC 160FL APO

Helix Nebula

APM107 Namibia

M27

Celestron 9.25/Hyperstar

M57 with remote galaxy

Celestron 9.25/Hyperstar