Our Milky Way Galaxy Truly Warped, at Least Around Edges

  • Our Milky Way Galaxy Truly Warped, at Least Around Edges

Our Milky Way Galaxy Truly Warped, at Least Around Edges

This finding allowed for an updated map of the galaxy's "stellar motions", says Deng Licai, senior researcher at NAOC.

A group of astronomers from Australia and China have built their "intuitive and accurate three-dimensional picture" by mapping the so-called "classical Cepheids". Their dimming and brightening changes helped them use them as distance indicators.

The shape of the Milky Way - our home galaxy - isn't exactly what we've always assumed it was. They found that the farther away the stars are from the center, the Milky Way's disc of stars becomes more "warped" and twisted.

A new study by the National Astronomical Observatories of Chinese Academy of Sciences (NAOC) might explain the Milky Way's spiral appearance - it's warped. The newly-created and most accurate 3D map of our galaxy reveals that it's warped and twisted, and even more fascinating.

Researchers established a robust Galactic disc model based on 1,339 variable stars which are four to 20 times larger than the Sun, and up to 100,000 times more luminous.

"It is notoriously hard to determine distances from the Sun to parts of the Milky Way's outer gas disc without having a clear idea of what that disc actually looks like", said Xiaodian Chen from the Chinese Academy of Sciences in Beijing.

Astronomers have observed a dozen other galaxies which showed similar progressively twisted spiral patterns in their outer regions. Such high stellar masses imply that they live fast and die young, burning through their nuclear fuel very quickly, sometimes in only a few million years. Combined with a Cepheid's observed brightness, its pulsation period can be used to obtain a highly accurate distance measurement.

"We usually think of spiral galaxies as being quite flat, like Andromeda, which you can easily see through a telescope", Macquarie University's Richard de Grijs, who took part in the study, said in a statement from Sydney.

"What we've shown is that the young stars in the Milky Way, particularly a type of star called Cepheid variables, actually show this warped distribution".