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Globular clusters are densely populated masses of stars, usually found orbiting the centres of galaxies. These objects can contain hundreds of thousands of stars and until now those found in our galaxy were thought to contain stars that formed in a single “burst” event around 10 billion years ago.

In a letter published in the Astrophysical Journal, ICRAR astronomer Dr Kenji Bekki outlined his discovery that the globular clusters we observe today may have actually evolved from massive ‘super clusters’ in the distant past.

Speaking about his findings Dr Bekki said: “The reason for our way of thinking until now is that we have based our assumptions on the more abundant population of stars that we observe within these objects.”

Using the first 3D computer simulations of massive cluster evolution, Dr Bekki’s research shows that globular clusters consist of at least two different populations of stars. Over billions of years, the original population of stars that once dominated has been eroded away through “tidal stripping” by the host galaxy.

“By using complex computer simulations, we have shown that ordinary globular clusters in our galaxy, the Milky Way, could have been up to 25 times more massive than the objects we see today,” said Dr Bekki.

“These ‘super clusters’ may not be classifiable as clusters at all, because they would once have been as massive as dwarf galaxies.”

This research provides a new insight into the formation and evolution of these intriguing objects and provides theoretical explanations for observed physical characteristics of globular clusters.