Final answer:
Astronomical phenomena include red supergiants, black holes, white dwarfs, and planetary nebulae, each representing different stages of stellar evolution, from high-mass stars expanding and cooling to smaller stars shedding their outer layers.
Step-by-step explanation:
Several astronomical phenomena and objects were enumerated, each one representing a different stage in the stellar evolutionary cycle:
- Red Supergiant: A late-stage high-mass star which has expanded and cooled after burning its core hydrogen. It is characterized by its large size, cool temperature, and bright red color.
- Black Hole: A point in space with such strong gravitational pull that nothing, not even light, can escape from it. It is the result of the collapse of a very massive star after a supernova explosion.
- White Dwarf: A small, dense remnant left after a low or medium-mass star has exhausted its nuclear fuel and shed its outer layers. It is very hot initially but will gradually cool over time.
- Planetary Nebula: A type of emission nebula created when a star like the sun ends its life by ejecting its outer layers into space, leaving behind a white dwarf.
- Low-mass Star: A type of star with mass lighter than about 2 solar masses which will typically become a red giant and then shed its outer layers to form a planetary nebula, with the core becoming a white dwarf.
- Heavy Star: Refers to a massive star that is at an advanced stage of its life. These stars will often expand and can give off large amounts of light as red supergiants or hypergiants before their eventual collapse.