Study: Our Galaxy Has Four Arms
LONDON (CBS Tampa) – For as long as we’ve known we live inside a galaxy, astronomers have been trying to figure out exactly what it looks like.
After all, we can’t very well step outside and take a picture.
Though we know the Milky Way spins around a super massive black hole, we don’t know as much about its outer structure.
Since 2008, scientists had been working with the idea that the galaxy has two spiral arms instead of four.
But new evidence may have put those two missing arms back, reports Popular Science.
Astronomers at the University of Leeds looked for younger, massive stars and found they clustered in four major arms.
Previous research had been focused on older, cooler stars like our sun and counted only two arms.
Young, massive stars are found in all four arms because they have shorter lifespans than cooler stars, and thus end up staying where they’re formed, said Melvin Hoare, a University of Leeds physicist who was part of the new study.
All four arms are capable of forming massive stars.