New Study Finds Milky Way Has Four Arms, Not Two
A new study provides evidence that our own home galaxy actually has four major spiral “arms,” instead of two. Can I just point out this is 100 percent more arms than our latest understanding of the shape of the Milky Way?
The evidence comes from the Red MSX Source survey, headquartered at the University of Leeds in the U.K., and was published last month in the journal Monthly Notices of the Royal Astronomical Society. Astronomers had previously thought the Milky Way had four arms, but in 2008, data from NASA’s Spitzer Space Telescope pointed to just two major arms.
"It isn’t a case of our results being right and those from Spitzer’s data being wrong. Both surveys were looking for different things," Melvin Hoare, a University of Leeds physicist who was part of the new study, said in a statement. “Spitzer only sees much cooler, lower mass stars, stars like our Sun, which are much more numerous than the massive stars that we were targeting.”