Fossilized relic discovered by Hubble is a bridge to the Milky Way’s past
“Globular clusters contain stars numbering from tens-of-thousands to tens-of-millions, all within a few hundred light years. Most globulars formed when the Universe was young, with stars over 12 or even 13 billion years old. The Milky Way alone contains around 200 globulars, including Terzan 5. Unlike most globulars, Terzan 5 contains two different populations of stars.”
From 19,000 light years away, Terzan 5 looks a lot like pretty much any globular cluster you’d expect to find: it’s massive, concentrated, with a huge number of stars at right around 12 billion years of age. But mixed in there is a second population of stars just 4.5 billion years old, and tremendously represented in number as well. We’ve never seen a globular like this before, which would have required about 100 million solar masses in gas to remain after the initial burst of formation. But Terzan 5 is an amazing find for containing stars similar to the ones found in the galactic bulge. Is it possible or even probable that this fossilized relic is a survivor of the starbursts that formed the stars in the galactic center, and that it survived them twice?