As a star forms, the photosphere first appears:

Question

Quizplus · Accepted Answer

The photosphere is the visible surface of a star, where light is emitted. It first appears when the protostar forms, as it starts to emit enough energy to create a visible surface. The photosphere is the visible surface of a star, and it forms when the protostar (the early stage of a star) has reached a sufficient temperature and density for its outer layers to become transparent to visible light. Therefore, the photosphere first appears when the protostar forms.

As a Star Forms, the Photosphere First Appears