Which stages do all stars have in common in their life cycles?(1 point)
A. nebula
B. white dwarf
C. protostar
D. black hole
A. nebula
The stages that all stars have in common in their life cycles are:
1. Nebula: Stars are born from massive clouds of gas and dust called nebulae. These nebulae are made up of hydrogen, helium, and trace amounts of other elements.
2. Protostar: Within a nebula, gravity causes the gas and dust to condense and form a dense core known as a protostar. As the protostar continues to accumulate mass, it heats up and begins to emit light.
3. Main Sequence: The protostar goes through a phase known as the main sequence, which is the longest stage in a star's life. During this stage, the star is fusing hydrogen atoms into helium in its core, creating a balance between the inward force of gravity and the outward force of radiation.
After the main sequence stage, the life cycle of a star can take different paths depending on its mass:
- Low to medium mass stars (like our Sun) will expand into a red giant and eventually shed their outer layers, forming a white dwarf.
- High mass stars will undergo a more explosive end, going through stages such as red supergiant, supernova, and potentially leaving behind a dense remnant known as a black hole or a neutron star.
Therefore, the common stages for all stars are nebula, protostar, and the main sequence. The white dwarf and black hole stages are specific to certain types of stars based on their mass.