Chapter 33, Problem 8TE

To determine

The time when the star dies.

Answer to Problem 8TE

When the stars are no longer capable of utilizing the thermonuclear fuels, then the star dies.

Explanation of Solution

The life of the star depends upon its mass. When the star is born, the hydrogen nuclei fuse to begin the thermonuclear reaction with sufficient pressure. A higher-mass star might have more material, but it also uses up the material more quickly due to its higher temperature. When the hydrogen in the center of the star is depleted, the star's core shrinks and heats up. This causes the outer part of the star, the star's atmosphere, which is still mostly hydrogen, to start to expand. The star becomes larger and brighter and its surface temperature cools, so it glows red. The star is now called a red giant star. Eventually, the core of the star becomes hot enough for the next nuclear reaction to start: atoms of helium collide and fuse into heavier elements such as carbon and oxygen. Following the red giant phase, the star becomes unstable and will eventually die.

If the stars no longer able to consume the thermonuclear fuel, the star collapse and it dies, outer & layers explode as a 'supernova.'

Conclusion:

Therefore, when the stars are no longer capable of utilizing the thermonuclear fuels, then the star dies.