Identify the phases in the life cycle of small and big stars. supernova: In this stage, the star collapses and produces elements heavier than iron. planetary nebula: In this stage, the star emits strong energy pulses that push away the outer layers creating a cloud of ionized gas around the core. neutron star: In this stage, the star has reduced to an extremely dense core. white dwarf: In this stage, the star has reduced to a dense core.

Explanation:

Some Astronomers believe the life cycle of small stars begins in this order:

Planetary nebula phase: this phase is the result of the previous red giant phase (when the star turns red in color). However, at this stage, the star keeps expanding, glowing, and getting hotter as it strives to complete its life--cycle.White dwarf phase: As the name implies, the star now has a reduced size and a dense core than during the Nebula phase, while still glowing with surface temperatures of over 100,000°C.Neutron star: This stage occurs next after the White dwarf phase which may result in the final death of the star. Here the star is reduced to an extremely dense core.

While the life cycle of big stars begins in the order:

Supernova phase: At this phase, the star collapses and produces other heavier elements.Neutron star phase or may formBlack Holes.