A protoplanetary nebula or preplanetary nebula is an astronomical object which is at the short-lived episode during a star's rapid evolution between the late asymptotic giant branch (LAGB)[a] phase and the subsequent planetary nebula (PN) phase. A PPN emits strongly in infrared radiation, and is a kind of reflection nebula. It is the second-from-the-last high-luminosity evolution phase in the life cycle of intermediate-mass stars.
Protoplanetary nebula known as IRAS 20068+4051 taken by Hubble's Advanced Camera for Surveys.
An interstellar butterfly - protoplanetary nebula Roberts 22
The Westbrook Nebula, a protoplanetary nebula.
Protoplanetary nebula IRAS 13208-6020 is formed from material that is shed by a central star.
A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
NGC 1535
X-ray/optical composite image of the Cat's Eye Nebula (NGC 6543)
Two cameras aboard Webb Telescope captured the latest image of this planetary nebula, cataloged as NGC 3132, and known informally as the Southern Ring Nebula. It is approximately 2,500 light-years away.
NGC 6326, a planetary nebula with glowing wisps of outpouring gas that are lit up by a binary central star
