by Deborah Byrd, EarthSky
A team of astronomers has produced a 3D map of our galaxy, the 1st accurate one, they say. It reveals our galaxy’s true shape as warped and twisted.
We think of spiral galaxies as being flat. You often hear the disk of our galaxy described as “flat as a pancake.” The large spiral galaxy next door – the Andromeda galaxy – looks flat through a telescope. But nature can be intricate, and, this week (February 4, 2019), astronomers made a surprising announcement. They said our home galaxy, the Milky Way, isn’t flat. Instead it’s warped and twisted.
Astronomers from Macquarie University and the Chinese Academy of Sciences used 1,339 classical Cepheid variable starsfor this study. They are stars that brighten and dim in a way that changes according to the stars’ true luminosities. Thus these stars have been used as classic distance indicators. The astronomers used data on these stars from the Wide-field Infrared Survey Explorer (WISE). The work led them to create a 3D map of what they said is the “real” shape of our Milky Way.