About 5 billion years ago, a huge cloud of dust and gas in the galaxy collapsed under gravity. As it shrank and became denser, it began to glow and the first nuclear fusion reactions occurred, forming the Sun. Approximately 4.6 billion years later, the Sun has used half of its hydrogen fuel and nuclear reactions now involve carbon, nitrogen, and oxygen. In around 5 billion more years, the Sun will expand into a red giant and engulf the Earth before collapsing into a white dwarf.

1. Our Sun. Evolution and
End.
Enrique J. Vervoor

2. History
•
At first, there was nothing. There was just a huge cloud of dust and gas in
the galaxy. About 5 billion years ago, there were enough hydrogen atoms
in the cloud for gravity to pull them together. As the cloud shrank, it
became denser. The atoms were soon moving so fast that this cloud began
to glow. When the cloud was hot enough, electrons and protons of the
hydrogen atoms flew apart. When two protons collided and atoms of
helium formed. This process is called fusion. Energy is produced in the
form of light and heat. The forces balanced and the cloud settled as the
sun. The leftover gas and dust formed the rest of matter.
Enrique J. Vervoor

3. Enrique J. Vervoor

4. Evolution
• approximately 4.6 billion years after the Sun's birth, some hydrogen fuel
has been turned into helium. It still haves the half of its life left. At the end
of his life, other nuclear reactions involving carbon, nitrogen and oxygen
will start. The core will contract and burn at higher temperatures and it
will become a red giant.
• A Planetary Nebula will form, light gas will envelope and expand to beyond
Earth's orbit, engulfing the Earth and warming the outer solar system.
Enrique J. Vervoor

5. End
• When it was born, the Sun was only 70% as bright as it is now. It will
evolve to double its current brightness in five billion years and Earth's
oceans will have boiled away, because of the heat, leaving a sterile planet.
• After it spends some time as a red giant, the Sun's nuclear reactions will
stop and it will collapse to become a white dwarf. Without a source of
power it will then slowly fade into oblivion becoming a black dwarf.
Enrique J. Vervoor

6. Definitions
White Dwarf:
 The remnant of a star that has collapsed, having an
extremely dense state with no empty space between its
atoms.
Black Darf:
 A black dwarf is a white dwarf that has sufficiently
cooled to no longer emit significant heat or light.
Red Giant:
 A star of great size and brightness that has a relatively
low surface temperature.
Enrique J. Vervoor

7. A photo of the sun taking from Las
Salinas de San Pedro del Pinatar
Enrique J. Vervoor