EN | FR
Life of a Star, 2023
Yesterday, I learned that someone had died.
It was such a sudden death that it made me think deeply about life.
What does life really look like?
The story I wanted to tell is the life of a star. From afar, we do not know what it truly is, but when we look more closely, it is fierce, magnificent, and beautiful.
Stars are born in enormous interstellar molecular clouds made of hydrogen, helium, dust, and other heavier elements. Whenever something is born in the universe, it begins with a small imbalance. If the universe were completely uniform, there would be no Earth, no Sun, and no life.
It is the same for stars. Their birth begins when the internal gravitational forces within a nebula become unstable. Within the nebula, there are regions of higher density and regions of lower density. As more dust gathers in the denser region, gravity becomes stronger, and as gravity grows stronger, even more dust is drawn in. In this way, a chain reaction continues.
As a large amount of matter is compressed into a small space, the molecules in the cloud begin to revolve around the region where gravity is strongest, forming a flattened disk of gas. This is the moment a star is born.
For an ordinary star like the Sun, it takes around 10 to 20 million years to reach this stage. As the mass, temperature, and density of the protostar increase, the star gradually begins to shine. Its core continues to contract, surrounding matter continues to fall inward, and as the internal temperature rises, nuclear fusion finally begins.
Hydrogen is, in a sense, the fuel of stars. A star transforms this fuel into helium, sustaining continuous nuclear fusion in its core. It uses its own body as fuel, creating energy and emitting light with that energy until its death. This is what we generally call the life of a star.
Eventually, that fuel runs out. When there is no hydrogen left for fusion, and if the star does not have enough heat to fuse helium, it begins to shrink. Ironically, the energy produced by gravitational contraction causes the outer layers of the star to expand. As stars approach death, they swell and become brighter.
The contraction continues slowly until it can go no further. What remains is only the core; the former broad and radiant appearance is gone. This remnant is called a white dwarf. In this way, the star dies, slowly releasing its remaining heat and light into space.
But what happens if a star is massive enough to reach the temperature required for helium fusion after its hydrogen has been exhausted?
Then the star is given another chance at nuclear fusion. This time, as it burns helium, its temperature rises beyond 100 million degrees, and it begins to shine more powerfully than ever before.
It enters a second life that will eventually culminate in a supernova. When this second life comes to an end, the star inscribes itself upon the universe in its own way. It ends its life in an immense explosion of light and heat, scattering the elements it has created in every direction. It is a majestic death. The star disappears, but the materials that once composed it are dispersed and become nourishment somewhere else.
An average star with a mass similar to that of the Sun lives for about 10 billion years.
A human life lasts, on average, about 80 years.
Whether human or star, each lives in its own time and burns through life until death. If this is what life is, then stars prove it with their whole bodies.
People often say that when we die, we return to the earth. But I want to say that we return to light.
I believe that one day, a part of me will become a star and shine.
It was such a sudden death that it made me think deeply about life.
What does life really look like?
The story I wanted to tell is the life of a star. From afar, we do not know what it truly is, but when we look more closely, it is fierce, magnificent, and beautiful.
Stars are born in enormous interstellar molecular clouds made of hydrogen, helium, dust, and other heavier elements. Whenever something is born in the universe, it begins with a small imbalance. If the universe were completely uniform, there would be no Earth, no Sun, and no life.
It is the same for stars. Their birth begins when the internal gravitational forces within a nebula become unstable. Within the nebula, there are regions of higher density and regions of lower density. As more dust gathers in the denser region, gravity becomes stronger, and as gravity grows stronger, even more dust is drawn in. In this way, a chain reaction continues.
As a large amount of matter is compressed into a small space, the molecules in the cloud begin to revolve around the region where gravity is strongest, forming a flattened disk of gas. This is the moment a star is born.
For an ordinary star like the Sun, it takes around 10 to 20 million years to reach this stage. As the mass, temperature, and density of the protostar increase, the star gradually begins to shine. Its core continues to contract, surrounding matter continues to fall inward, and as the internal temperature rises, nuclear fusion finally begins.
Hydrogen is, in a sense, the fuel of stars. A star transforms this fuel into helium, sustaining continuous nuclear fusion in its core. It uses its own body as fuel, creating energy and emitting light with that energy until its death. This is what we generally call the life of a star.
Eventually, that fuel runs out. When there is no hydrogen left for fusion, and if the star does not have enough heat to fuse helium, it begins to shrink. Ironically, the energy produced by gravitational contraction causes the outer layers of the star to expand. As stars approach death, they swell and become brighter.
The contraction continues slowly until it can go no further. What remains is only the core; the former broad and radiant appearance is gone. This remnant is called a white dwarf. In this way, the star dies, slowly releasing its remaining heat and light into space.
But what happens if a star is massive enough to reach the temperature required for helium fusion after its hydrogen has been exhausted?
Then the star is given another chance at nuclear fusion. This time, as it burns helium, its temperature rises beyond 100 million degrees, and it begins to shine more powerfully than ever before.
It enters a second life that will eventually culminate in a supernova. When this second life comes to an end, the star inscribes itself upon the universe in its own way. It ends its life in an immense explosion of light and heat, scattering the elements it has created in every direction. It is a majestic death. The star disappears, but the materials that once composed it are dispersed and become nourishment somewhere else.
An average star with a mass similar to that of the Sun lives for about 10 billion years.
A human life lasts, on average, about 80 years.
Whether human or star, each lives in its own time and burns through life until death. If this is what life is, then stars prove it with their whole bodies.
People often say that when we die, we return to the earth. But I want to say that we return to light.
I believe that one day, a part of me will become a star and shine.