A nebula. That's composed mostly of hot gasses. Hence, the name. Hot nebula.
That is hot enough to ignite hydrogen fusion, so the nebula becomes a star (possibly with planets).
a colorful cloud of gas that glows because it is heated by light from nearby hot stars
A solar nebula is related to the formation of our Solar System, any other nebula is just a nebula.
The helix nebula is more close than the ring nebula, as well as much brighter and larger than the ring but with low surface brightness.
A nebula. That's composed mostly of hot gasses. Hence, the name. Hot nebula.
That is hot enough to ignite hydrogen fusion, so the nebula becomes a star (possibly with planets).
planetesimals formed the disk
A nebula, in general, is not particularly hot. They are usually visible due to embedded stars.
A nebula, in general, is not particularly hot. They are usually visible due to embedded stars.
The Crab Nebula is a nebula.
A disk
a colorful cloud of gas that glows because it is heated by light from nearby hot stars
Triffid Nebula, Eagle Nebula, Cat's Eye nebula
A solar nebula is related to the formation of our Solar System, any other nebula is just a nebula.
nebula
The Stingray Nebula (Hen 3-1357) is a planetary nebula. (The youngest known).