This is the order of the stages, along with additional details from the image:
- After "main-sequence," the star becomes a red giant, so write red giant in the first blank after "main-sequence."
- Following that stage, the star would shed its outer layers and the core would become a white dwarf, so write white dwarf in the next blank.
- Finally, after a very long time, the white dwarf would cool down to become a black dwarf, so write black dwarf in the last blank.
What are these stars?
1. Nebula: This is a giant cloud of gas and dust in space, the birthplace of stars. The image shows a dark nebula with bright blue stars in the background.
2. Protostar: As gravity pulls the gas and dust in the nebula together, it forms a hot, dense core called a protostar. The image shows a young star still surrounded by the remnants of the nebula.
3. Main Sequence Star: When the protostar starts fusing hydrogen into helium at its core, it becomes a main sequence star. The Sun is a main sequence star. The image shows a stable, yellow star shining brightly.
4. Red Giant: When the hydrogen fuel in the core runs out, the star expands and cools, becoming a red giant. The image shows a large, red star surrounded by a glowing gas cloud.
5. Planetary Nebula: If the red giant has a low to medium mass, it will eventually shed its outer layers, forming a planetary nebula. The image shows a colorful, glowing gas cloud with a faint star at its center.
6. White Dwarf: The remaining core of the red giant becomes a hot, dense white dwarf. The image shows a small, white star.
7. Supernova (optional): If the red giant has a high mass, it will collapse and explode in a supernova, leaving behind a neutron star or black hole. The image doesn't show a supernova, but it's included in the cycle for some stars.
8. Neutron Star or Black Hole: The final stage depends on the mass of the remaining core. If it's below a certain limit, it becomes a neutron star. If it's above the limit, it collapses into a black hole. The image shows a small, blue circle representing a neutron star.