The Sun is at the center of our Solar System, providing the essential source of energy required for life as it is on Earth. Due to its significance, and the fact that it consists of an estimated 67 different elements all interacting with one another, its interesting to discover its overall fate.
So, will the Sun become a White Dwarf? The short answer is yes, eventually (scientists estimate this will occur in around 5 billion years). The Sun will become a White Dwarf following an interim phase of being a Red Giant. This life cycle occurs as the Suns fuel source (Hydrogen) will over time burn through, and through a process known as Nuclear Fusion (whereby Hydrogen and Helium interact), the Sun will expand to become a Red Giant. From there and after a period of time, it will then collapse into a smaller, dense White Dwarf.
White Dwarfs are small, compact yet dense stars that drop in temperature after consisting as a Red Giant. The Sun, is just like the majority of other stars, in that it will follow this similar fate. A White Dwarf is there are perfect phenomena to study to observe the trajectory and evolution of stars, and give us insights in to what will become of our Solar Systems central and pivotal one.
Why Do Stars Become White Dwarfs
Due to the chemical composition of our Sun, a process known as Nuclear Fusion converts the predominanet element Hydrogen (~70%) into Helium. The interaction causes an extremely large amount of energy to be released; causing light and heat (which is why we experience this down on Earth).
Ultimately, the majority of stars, like the Sun, run out of their fuel, in this case Hydrogen. The transition to higher Helium will cause the Sun to swell and expand, and it is during this phase that it becomes known as a Red Giant.
Through time, this Red Giant will shrink and cool, into a smaller denser mass and what scientists and Astronomers refer to as White Dwarfs.
Interestingly, White Dwarfs are actually similar in mass to the Sun, despite its significantly smaller size (around the size of Planet Earth).
Asteroseismology is the field of science that studies the inside of White Dwarfs. They do this using star quakes, pulsating radiation that escapes.
As White Dwarfs are compact and low in temperature, they appear faint and are difficult to observe and locate. A tool known as a Photometer is typically attached to a telescope to observe small changes in a White Dwarf, but will only be used once they have initially been found. It is through changes in light that a Asteroseismologist can get an understanding of the age of a White Dwarf due to its relative temperature.
Asteroseismologists predict that a White Dwarf consists of a dense core of Carbon and Oxygen, wrapped in a small layer of Hydrogen/Helium. They can only extrapolate data from computer models as it is not possible to see inside a White Dwarf, only its surface.
Evolution of our Sun
As a star, the Sun will go through numerous stages and processes in its overall evolution. At present, it is medium-aged, but in time will become a White Dwarf.
The Sun has endured 5 billion years of Nuclear Fusion; whereby it converts Hydrogen into Helium. In a further 5 billion years time, this Hydrogen source will start to run out.
It is Gravity that will cause the Helium inside the Sun to shrink and heat up. Opposingly, its outside layer will grow and drop in temperature. This interaction will cause the Sun to become a Red Giant, which will be large enough to consume the Earth.
When the core of the Sun gets hot enough, its helium will reside as the new primary fuel, and this will result in larger atoms of Carbon and Oxygen being produced.
The outer layers of the Sun will simply drop off; becoming a Planetary Nebula within space. The core will remain but will be much more dense and command a lot more Gravity.
The remaining core will eventually cool down, whereby it transitions into its White Dwarf phase. In time, it will ultimately stop producing light and shining.