A planetary nebula is the phase of a
A.
neutron star late in its life.
B.
planet before it becomes a star.
C.
main sequence star late in its life.
D.
protostar before it becomes a white dwarf.
D. protostar before it becomes a white dwarf.
C. main sequence star late in its life.
To determine the correct answer, we need to understand what a planetary nebula is and its formation process.
A planetary nebula is a type of emission nebula formed from the outer layers of a dying star. It occurs during the late stages of stellar evolution when a low to intermediate mass star (a main sequence star) exhausts its nuclear fuel and begins to shed its outer layers.
The correct answer is:
C. A main sequence star late in its life.
To arrive at this answer, we can eliminate the other options:
A. A neutron star is a highly dense remnant of a massive star that has gone through a supernova explosion. Neutron stars do not form planetary nebulae.
B. Planets do not transform into stars. Stars are formed from the collapse of gas and dust in a nebula, while planets are formed through the accumulation of material within a protoplanetary disk.
D. A protostar is an early stage in the formation of a star, characterized by the accumulation of material and the beginning of nuclear fusion. It does not directly evolve into a white dwarf or form a planetary nebula.
Therefore, the correct answer is C. A main sequence star late in its life.