MAIN SEQUENCE STARS

• For a star to be born there must be nuclear

fusion in its core. This is where star life

begins and stars in this stage are known as

sequence stars.

DWARF STARS

• Yellow Dwarf Stars – These are among the main sequence stars but are small in size. A good example of these stars is the sun.

• White Dwarfs – Because of their low mass, there are some stars that fail to enter the giant phase at the end of their lives. The outer part of the star merges with the interstellar space and the only part that remains is its core.

• Brown Dwarfs – These are also known as failed stars. Just like normal stars, they are formed in the same way but they do not accumulate enough mass to generate nuclear fusion in the core hence the name failed stars. They are smaller than the normal stars.

GIANT STARS

• Blue Giant –Huge, extremely hot blue star.

• Red Giant – When the hydrogen fuel in a star is

completely used up, the star transitions and

becomes a red giant star

SUPER GIANTS

• These are the biggest stars in the entire

universe. They consume hydrogen at an

enormous rate. This means that they die

off very fast and they disintegrate as they

detonate as supernovae.

NEUTRON STARS• Neutron Stars – These are actually not stars they

are stellar remnants. After a star’s life has come

to an end it goes through a supernova explosion

and the core remains. These remnants are what

are known as neutron stars.

• Pulsar – This is a rapidly rotating neutron star.

This star emits energy in pulses that is the reason

it is known as a pulsar.

OTHER TYPES OF STARS

• Black Holes – While not technically stars, these are formed as a result of

the massive gravity created by large stars collapsing in on themselves.

• Variable Stars – These are stars that tend to change their brightness.

Unlike other stars that maintain a constant brightness, these stars tend

to vary their brightness from time to time.

• Binary Stars – This is a system of 2 stars that go around each other or a

common centre of mass cloud. True binaries revolve around one

another. A good example of these stars is Polaris.

STAR DEATH

• The Spectacle of Star Death

https://youtu.be/E6FpSOg2BxE

“REINCARNATION” OR QUIET STAR DEATH

• When some stars die, a cloud called a planetary

nebula is formed around the core of the star, which

is now classified as a white dwarf.

• The material from the nebula floats out into space

and is the building blocks for new star formation

SUPERNOVA

• A star that suddenly becomes brighter and gives

out a huge amount of energy because it is

exploding and dying.

CHALLENGE!

• What is the plural of “supernova?”