Globular Cluster 47 Tucanae

Rejuvenated Stars, called "Blue Stragglers," in Globular Cluster 47 Tucanae (left)

The core of globular cluster 47 Tucanae is home to many blue stragglers, rejuvenated stars that glow with the blue light of young stars. A ground-based telescope image (on the left) shows the entire crowded core of 47 Tucanae, located 15,000 light-years away in the constellation...

47 Tucanae

There's more than one way to make a Blue Straggler

Spectrum of Blue Straggler Star in 47 Tuc

A star's light yields clues about its identity which are not revealed in an image. That's why astronomers use spectrographs to decode the light. A spectrograph disperses light into its component colors, providing information on a star's rotation velocity, temperature, and...