Blue Straggler Stars in Globular Cluster M53 . ... Credit Copyright: ESA/Hubble , NASA Explanation: If our Sun were part of M53, the night sky would glow like a jewel box of bright stars. M53 , also known as NGC 5024, is one of about 250 globular clusters that survive in our Galaxy. Most of the stars in M53 are older and redder than our Sun, but some enigmatic stars appear to be bluer and younger. ... These unusual stars are known as blue stragglers and are unusually common in M53. ...