What is the leading explanation for the existence of blue stragglers in ancient stellar populations?

Answer

They are older stars rejuvenated by receiving new material from a companion in a binary system

The most compelling explanation is that these stars were likely older, cooler stars that were rejuvenated by receiving new material, perhaps hydrogen, from a companion star in a binary system.

What is the leading explanation for the existence of blue stragglers in ancient stellar populations?
astronomylifespanstarsblue star