 In 2019 I released the How Old Are Stars video, where we covered HR diagram turnoff points to find the age of star clusters. Here's NGC 1466, a very old globular cluster in the large Magellanic cloud 160,000 light years away. It has a mass equivalent to roughly 140,000 suns and a turnoff point that indicates its age as around 13.1 billion years, making it almost as old as the universe itself. All high mass blue stars would have moved into their giant and supergiant phases by now. But we do see blue stars in this and many other clusters of similar age. These massive hot blue stars are a special type of reinvigorated stars called blue stragglers. Under certain circumstances, stars receive extra fuel that builds them up and subsequently brightens them. This can happen if one star pulls matter from a neighbor or if two stars collide. Blue stragglers are so called because of their blue color and the fact that their evolution lags behind that of the rest of the stars in the cluster.