[https://m.dw.com/en/what-21-stars-tell-us-about-the-universe/a-55977304](https://m.dw.com/en/what-21-stars-tell-us-about-the-universe/a-55977304) >"How do you whittle down the 200 billion in our Milky Way galaxy to a mere 21? Focus on the ones that have changed human understanding of the universe, as astronomer Giles Sparrow told DW."