At what point in time do we say that the protosun became the Sun?
A) when thermonuclear fusion reactions began at its center
B) when it became hot enough to emit light and heat
C) when the temperature began to rise at its center
D) when planetary formation was complete

Question

Quizplus · Accepted Answer

The protosun officially became the Sun when thermonuclear fusion reactions began at its center. This is because the Sun's energy primarily comes from these reactions, and the release of this energy is what causes the Sun to emit light and heat. The other options may signify important stages in the Sun's formation and development, but they do not mark the point at which it became the Sun in the true sense.

At What Point in Time Do We Say That the Protosun