Some stars appear to defy time itself. Nestled within ancient star clusters, they shine bluer and brighter than their neighbors, looking far younger than their true age. Known as blue straggler stars, these stellar oddities have puzzled astronomers for more than 70 years. Now, new results using the NASA/ESA Hubble Space Telescope are finally revealing how these “forever young” stars come to be and why they thrive in quieter cosmic neighborhoods.
Why blue stragglers puzzle astronomers Blue straggler stars stand out in old star clusters because they appear hotter, more massive and younger than stars that should all have formed billions of years ago. Their very existence contradicts standard theories of stellar aging, prompting decades of debate over whether they are created through violent stellar collisions or through more subtle interactions between pairs of stars.
A new study provides some of the clearest evidence yet that blue stragglers owe their youthful appearance not to collisions, but to life in close stellar partnerships, and to the environments that allow those partnerships to survive. The work is published in the journal Nature Communications.
