A White Dwarf Star remains.
nebula
The Stingray Nebula (Hen 3-1357) is a planetary nebula. (The youngest known).
"The Crab" is a nebula.
a type of nebula
A cloud in outer space consisting of gas or dust and planetry nebula is one of the types also called ring nebula or A planetary nebula is an emission nebula consisting of a glowing shell of gas
The Helix Nebula is a planetary nebula located in the constellation Aquarius, while the Ring Nebula is a planetary nebula located in the constellation Lyra. The Helix Nebula appears more like a disk or helix shape, while the Ring Nebula appears as a ring or donut shape due to its orientation.
Emission nebula glow and reflection nebula reflect the light form other stars
The crab nebula.
protostar or nebula
The eye of god is a Helix nebula. Close to a Planetary nebula.
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It is called a Nebula (nebulae for plural). no sorry but your wrong it is a coma It can be both it just depends. The question needs to be more specific