Embedded in a dense star field, NGC 6397 is one of the closest globular clusters to us. Its stars are only a few lightweeks apart, while the star closest to us is over four light years away. Globular clusters are the oldest objects in galaxies and consist mainly of old, red stars. Nevertheless, blue and young stars, known as “blue stragglers”, can always be found in the centre of the star clusters. These stragglers keep themselves young through cannibalism, apparently snatching matter from a neighbouring star.
Globular Cluster NGC6397