Life+Cycle+of+a+Star

=Life Cycle of a Star=

Mitchell King & Arun Prakash
Stars are in many ways like people, within a group we can find babies, children, teenagers, adults and senior citizens. Like humans, stars pass through different stages in their lives. They are created, mature and eventually die. However, unlike humans most stars live for millions or billions of years.

Nebula
A Nebula is a cloud of gas and dust in space. Some Nebulae are regions where new stars are being formed, while others are the remains of dead or dying stars. Nebulae come in many different shapes and sizes. The four main types of Nebula are the...
 * Planetary Nebula
 * Reflection Nebula
 * Emission Nebula
 * Absorption Nebula

Star
A star is a luminous globe of gas that produces its own heat and light. It consists of mostly hydrogen and helium gas. They are the next stage throughout the life of a star. They live for less than a million years until exploding as a supernovae.

Red Giant
Red giants a bright stars with cool surfaces. It is formed in the later stages of the evolution of a star. These red giants are so bright because they are so large, although their surface temperature is lower than the suns. These stars are often called Super Giants.

Red Dwarf
These stars are very small, faint, and cool. These stars are about one tenth the size of the sun. These stars burn out very slowly and have a lifetime of about 100 billion years.

White Dwarf
This star is very small and very hot. It is the last stage in the life cycle of the star. Our sun is a white dwarf. White dwarves are the shrunken remains of what was once a normal star. White dwarves cool and fade over several billion years.

Supernova
A supernova is when a star explodes and dies. Often when a supernova occurs, the star obtains the brightness of 100 million suns for a short time. There are two types of supernova. Type 1: This occurs in binary star systems in which gas from one star falls on to a white dwarf, causing it to explode. Type 2: This occurs in stars that are ten or more times bigger than the sun, which have internal nuclear reactions, causing it to explode.These leave behind neutron stars and black holes.

Neutron Star
This star is made up of mostly neutrons and are produced when a supernova explodes, causing the protons and electrons to combine to produce a neutron star. Neutron stars are very dense. Pulsars are believed to be neutron stars that are spinning rapidly.

Black Holes
Black holes are formed from massive stars at the end of their life. The gravitational pull of a black hole is so great that nothing can escape from it, not even light. Black holes distort the space around them, and can suck in matter around them, including stars.

Sun
Our Sun is one of the largest stars in the Milky Way Galaxy, in fact, it is larger than 85% of other stars in our galaxy. The Sun is so large that 1million Earth's would be able to fit inside it. It is present in many old legends and myths with the Greeks calling it Helios and the Romans calling it Sol, we get the name Sun from the Roman word Sol. The Sun is an approximate 70% Hydrogen and 28% Helium by mass. The core of the sun slowly changes the Hydrogen to Helium so these figures are constantly changing. <span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif;"><span style="color: #000000; font-family: arial,helvetica,sans-serif; font-size: 13px; font-weight: normal; line-height: 19px;">

=Fun facts about stars:=
 * Most stars are between 1 to 10 billion years old.
 * The oldest star that has been discovered so far is HE 1523-0901, which is about 13.2 billion years old.
 * Stars come in different colours. Hot stars give off blue light while cooler stars give off red light.
 * Some stars are 600,000 times as bright as our sun.
 * Most stars are red dwarves
 * Many stars come in pairs. These are called binary stars.
 * The largest star in the universe is called VY Canis Majoris. It is about 1800 times the size of the sun and would be able to engulf Saturn.
 * There are 200-400 billion stars in our galaxy.
 * Stars are very far away from Earth. The closest star to Earth, Proxima Centauri, is about 4.2 light years away.