Chapter 33, Problem 7TE

What event marks the birth of a star?

To determine

The event that mark birth of a star.

Answer to Problem 7TE

Atoms of light particles are compressed with the sufficient pressure of their nuclei to experience fusion and form stars.

Explanation of Solution

A protostar is a dense ball of gas that is not yet hot enough at the center to start nuclear reactions. The young star starts converting hydrogen to helium via nuclear fusion reactions. If atoms of light particles are compressed following the adequate pressure for their nuclei to experience fusion, a star is born.

All stars are the event of a balance of forces, the force of gravity contracts atoms in interstellar gas until the fusion reactions occur. That is when the density and temperature at the core of the gravitationally collapsing nebula reach values when nuclear fusion is triggered and sustained, which marks the birth of the star.

Conclusion:

Therefore, atoms of light particles are compressed with the sufficient pressure of their nuclei to experience fusion and form stars.