There’s a mysteriously shaped cluster of stars at the center of the Andromeda Galaxy, around 2.5 million light-years away and neighbor to the Milky Way. It’s been causing astronomers to furrow their brows and stroke their chins for decades at this point.

However, new research into how galaxies – and the supermassive black holes at their centers – can collide together may offer an explanation for this cluster. It seems that it might be caused by a gravitational ‘kick’, something similar to the recoil of a shotgun but on a cosmic scale.

This latest study suggests the kick would be powerful enough to create an elongated mass of millions of stars – technically known as an eccentric nuclear disk – instead of the sort of symmetric star cluster that would typically be in the center of a galaxy like Andromeda.