M57 also called the Ring Nebula is a planetary nebula (planetary nebula have nothing to do with planets). They are formed when a star near the end of its evolutionary life expels its outer layers as it shrinks down to the white dwarf stage. The planetary nebula name comes from the early days when nebula such as this looked like planetary disks to the early observers.   

Sometimes called the Oyster Nebula, NGC 1501 is a planetary nebula located in Camelopardalis (The Giraffe). The central star shed its outer layers and those layers are now illuminated by the central star. The central star is also reported to be a pulsating variable star with an extremely short period of brightness changes.

Messier 57 is a planetary nebula located in the constellation of Lyra. Often referred to as the Ring nebula as it resembles a small ring visually in a telescope. A planetary nebula is formed when a star in the latter stages of its life swells up into a red giant phase and the outer layers are expelled into the surrounding space as the star contracts down to a white dwarf. The ionizing radiation causes the surrounding gas to fluoresce.

Independently discovered by Charles Messier and Antoine Darquier de Pellepoix in January 1779.

Imaged with the ES127 refractor and the Atik314L+ mono camera.

Also visible in this highly stretched version are several background galaxies.

Messier 27 or commonly called the Dumbbell Nebula or Apple Core nebula due to its appearance visually through a telescope. It is a planetary nebula which is a misnomer as it has nothing to do with planets. It is formed as a star enters it's last stages of its life as the outer layers swell out and before they dissipate out into space. The surrounding layers are ionized by the remaining hot core. The remains of the star eventually contract down into a white dwarf to slowly cool over the eons. The central white dwarf is one of the largest known white dwarfs. The estimated age of the nebula is around 14,600 years.

Imaged with the ES127 refractor and the Atik 314L+ mono camera.

Messier 46 is an open cluster located in the constellation of Puppis. The cluster contains approximately 500 stars and is estimated to be 300 million years old. Also visible in the cluster is a planetary nebula designated NGC 2438, however the nebula does not appear to be part of the cluster as it's radial velocity is different. Also barely visible is another planetary PK231+4.1 up and left of M46.

Messier 27 is often called the Dumbbell Nebula or Apple Core Nebula because of the brighter lobes on each side of it. It is located in the constellation of Vulpecula, at a distance of 1300 light years.

M27 is a planetary nebula which is a bit of a misnomer since it has nothing to do with planets. The first ones discovered looked a bit like planetary systems, but planetary nebula are created when a dieing star casts off its outer layers after a star's red giant phase. The nebula is made to glow from ionizing radiation from the remains of the star core which shrinks down to form a white dwarf.

Messier 27 was the first planetary nebula cataloged by Charles Messier.

Imaged with the RC10, and the ZWO 1600 MMC monochrome camera.