Spheroid A

The spheroid coalesced, probably as a consequence of cooling, and started a new cycle of radiative transfer. This latest formation of the spheroid represents one of the very last big transitions of the Sun's history, the other being the breakup of the previous spheroid in the main sequence. When this spheroid finally ceased to rotate and could no longer continue to pass through the Sun's turbulent outer atmosphere, it became a protostar, a small, dense ball of gas that would eventually become a star.