M10
Discovered by Charles Messier in 1764, M10 is a globular cluster located in the constellation Ophiuchus. It is roughly 15,000 light-years from Earth and has an apparent magnitude of 6.4. This cluster can be spotted using a pair of binoculars and is most easily observed during July.
M10 is notable for its high population of blue stragglers — stars that appear to be far younger than their neighbors. The stars in globular clusters are thought to have formed and aged together, so they should all be roughly the same age. These anomalous, bluer stars were created either by collisions between stars or other stellar interactions. Such events are easy to imagine in densely populated globular clusters, in which up to a few million stars are tightly packed together.
https://www.nasa.gov/feature/goddard/2017/messier-10
M10 is notable for its high population of blue stragglers — stars that appear to be far younger than their neighbors. The stars in globular clusters are thought to have formed and aged together, so they should all be roughly the same age. These anomalous, bluer stars were created either by collisions between stars or other stellar interactions. Such events are easy to imagine in densely populated globular clusters, in which up to a few million stars are tightly packed together.
https://www.nasa.gov/feature/goddard/2017/messier-10