A tweet posted by astronomer Dustin Lang from the University of Toronto led to scientists investigating a three-dimensional bulge at the heart of the Milky Way's flat structure.
"The bulge is a key signature of formation of the Milky Way," Melissa Ness, a post-doctoral researcher from the Max Planck Institute for Astronomy in Germany notes. "If we understand the bulge we will understand the key processes that have formed and shaped our galaxy."
The bulge is evidence that no other major astronomical event since the Milky Way was formed has taken place - otherwise, the distinctive 'X' shape would not have been maintained. And its discovery could possibly spur a deeper understanding of how the galaxy was formed.
"The X-shape morphology of the bulge in itself and the fraction of bulge stars that comprise orbits within this structure has important implications for the formation history of the Milky Way … and spiral galaxies in general," Ness and Lang published in a paper.
Other scientists, such as Luke Davies of the International Centre of Radio Astronomy Research, are quick to point out that while the data was "reasonably compelling" however, at the present time, the pair working on it hasn't really done anything to truly study the X-shaped structure.
To that end, this is just "the first evidence we have for it, and there should be lots more detailed observations to confirm it before you say it's irrefutable," as Davies adds
He does however, agree that the existence of such an X-shaped structure would indeed tell us all about how the Milky Way galaxy was formed.