Life cycle of the stars.
You shall learn the Life cycle of stars this day ^.^
First Phase of the Life Cycle of a Star
Nuclear fusion powers a star most of its life, initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars ,like our sun, begin to fuse hydrogen along a spherical shell surrounding the core of the star. This is the first phase.
Second Phase of the Life Cycle of a Star
subgiant stage is the name of this phase. The elements that make up a star during this state are hydrogen, and poor-metal. A region of condensing matter will begin to heat up and start to glow forming Protostars. If a protostar contains enough matter the central temperature reaches 15 million degrees centigrade. This is what occurs.
When a star dies, What happens??
It matters on what type of star it is whether its big or small and what stage it starts out at. A star dies from the gravity and pressure then is pushed on it making it want to collapse on itself. A supernova is a stellar explosion that briefly outshines an entire galaxy. B the sudden re-ignition of nuclear fusion in a degenerate star, or by the gravitational collapse of the core. After a star dies a planetary nebula is produced. A planetary nebula is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives.