Question
A black hole begins to form as an aging star abruptly collapses when it ceases
gaining mass by collecting gas and dust
. This occurs after the star has consumed its component elements in this order:
gaining mass by collecting gas and dust
. This occurs after the star has consumed its component elements in this order:
Answers
Answered by
GPT-4o mini
The process of a star's life and its eventual collapse into a black hole involves several stages of nuclear fusion and the consumption of its component elements. For massive stars that eventually become black holes, the typical sequence of element consumption is as follows:
1. **Hydrogen:** The star primarily fuses hydrogen into helium in its core (hydrogen burning) during the main sequence phase.
2. **Helium:** Once hydrogen is depleted in the core, the star begins to fuse helium into heavier elements (helium burning).
3. **Carbon:** As the helium supply is exhausted, the core temperature rises enough to ignite carbon fusion, creating elements like oxygen and magnesium.
4. **Oxygen:** Following carbon burning, oxygen becomes the next fuel for fusion, creating heavier elements like neon and silicon.
5. **Silicon:** Once the oxygen supply is depleted, the star is capable of fusing silicon into iron and nickel through a process called silicon burning.
The process culminates with the generation of iron. Iron is the end point of fusion in a star’s life because it does not release energy when fusing (it requires energy instead). When a star's core is primarily composed of iron, nuclear fusion can no longer counterbalance the gravitational forces pulling inward.
After exhausting its nuclear fuel, the core collapses under gravity, and if the mass of the core exceeds a certain threshold (approximately 2.5-3 solar masses, known as the Tolman-Oppenheimer-Volkoff limit), it continues to collapse, leading to the formation of a black hole. The outer layers may be expelled in a supernova explosion, but the remaining core becomes an extremely dense singularity, encapsulated by an event horizon.
1. **Hydrogen:** The star primarily fuses hydrogen into helium in its core (hydrogen burning) during the main sequence phase.
2. **Helium:** Once hydrogen is depleted in the core, the star begins to fuse helium into heavier elements (helium burning).
3. **Carbon:** As the helium supply is exhausted, the core temperature rises enough to ignite carbon fusion, creating elements like oxygen and magnesium.
4. **Oxygen:** Following carbon burning, oxygen becomes the next fuel for fusion, creating heavier elements like neon and silicon.
5. **Silicon:** Once the oxygen supply is depleted, the star is capable of fusing silicon into iron and nickel through a process called silicon burning.
The process culminates with the generation of iron. Iron is the end point of fusion in a star’s life because it does not release energy when fusing (it requires energy instead). When a star's core is primarily composed of iron, nuclear fusion can no longer counterbalance the gravitational forces pulling inward.
After exhausting its nuclear fuel, the core collapses under gravity, and if the mass of the core exceeds a certain threshold (approximately 2.5-3 solar masses, known as the Tolman-Oppenheimer-Volkoff limit), it continues to collapse, leading to the formation of a black hole. The outer layers may be expelled in a supernova explosion, but the remaining core becomes an extremely dense singularity, encapsulated by an event horizon.