Life Cycle of Stars:
The First Stage - Stars are initially formed when clouds of dust and gas particles which can be found throughout the universe.The force of gravity is what makes all the particles to come spiraling in together. This results in what is known as gravitational energy which is then converted into heat energy and with all this happening the energy rises.
The Second Stage - As the temperature rises and gets to a hot enough heat, hydrogen nuclei begin to form and undergo a nuclear fusion to form helium nuclei and start to give out massive amounts of heat and light. This is where the star is born and in which immediately enters a long stable period where the heat created by the nuclear fusion provides an outward pressure in order to balance the force of gravity by pulling everything inwards. This stable period is called a 'Main Sequence Star' which normally lasts for about 10 billion years.
The Third Stage - After a while the hydrogen begins to run out and starts to swell becoming a 'Red Giant,' it is red because the surface cools. Small stars begin to cool and contract into what is called a 'White Dwarf' and then finally becomes a 'Black Dwarf' after the light fades completely. Big stars however start to glow brightly again as they undergo more fusion and expand and contract which enables it to form heavier elements in various nuclear reactions. Eventually these stars explode in what is known as a 'Supernova.'
The Fourth Stage - The exploding Supernova throws the outer layers of dust and gas of what was once a shining bright star into space. This big event leaves behind a very dense core called a 'Neutron Star,' and if the star was big enough then this core will become a 'Black Hole.' The dust and gas thrown off directly after the Supernova will form into 'Second Generation Stars' like our Sun. The heavier elements made by a big star are only made in the final stages, just before the final supernova. This proves that the presence of heavier elements in the sun and the inner planets is clear evidence that our earth and all the planets in our solar system have formed from the remains of an old dead star.
The Hertzsprung-Russell-Diagram:
Danish astronomer Ejnar Hertzsprung and American astronomer Henry Norris Russell discovered that when they compared the luminosity with the type of light that was observed from stars, there were many patterns that emerged. Hertzsprung presented tables of luminosities and star colors in 1905, noting many correlations and trends within the table itself.Russell published similar data in a diagram in 1913. It is now called the Hertzsprung-Russell Diagram in honor of these two great men.
Is there a Pattern? - Yes there is a quite significant pattern found throughout this graph.
Henry Norris Russell noticed that almost 90% of the stars in the table fell along a diagonal ribbon that stretched from the top-left to the bottom-right of his diagram. The stars that fell into this diagonal ribbons were classified as the Main Sequence Stars, of which our Sun is a part of.
Henry Norris Russell noticed that almost 90% of the stars in the table fell along a diagonal ribbon that stretched from the top-left to the bottom-right of his diagram. The stars that fell into this diagonal ribbons were classified as the Main Sequence Stars, of which our Sun is a part of.