It turns out that our galaxy of the Milky Way is really deformed, at least on the most distant edges.
Scientists from China and Australia released an updated 3D map of the Milky Way on Tuesday. They used 1,339 pulsating stars – young and newly cataloged stars, larger and brighter than our sun – to map the shape of the galaxy.
The further away from the center, the more deformation, or twist, exists in the outer disk of hydrogen gas in the Milky Way. Researchers say the deformed spiral pattern is probably caused by the rotating force of the huge inner disk of stars.
"Generally we think of spiral galaxies as being quite flat, like Andromeda, which you can easily see through a telescope," said Richard de Grijs of Macquarie University, who participated in the study, in a Sydney statement.
Research leader Xiaodian Chen of the Chinese Academy of Sciences in Beijing said it was difficult to determine the Sun's distances to the edges of the Milky Way, "without having a clear idea of how this disk actually looks." The stars on which the map of his team is based – known as classical Cepheids – provided substantial measurement accuracy.
At least a dozen other galaxies appear to have distorted edges in a similar spiral pattern, so in this respect we are hardly unique.
The study appears in the journal Nature Astronomy.