Artist’s concept of what astronomers now believe is the overall structure of the
spiral arms in our Milky Way galaxy. Image via NASA and Wikimedia Commons.

EARTHSKY // FAQS // SPACE Deborah Byrd JAN 06, 2013

Which spiral arm of the Milky Way contains our sun?

We live in an island of stars called the Milky Way, and many know that our Milky Way is a spiral galaxy. In fact, it’s a barred spiral galaxy, which means that our galaxy probably has just two major spiral arms, plus a central bar that astronomers are only now beginning to understand. But where within this vast spiral structure do our sun and its planets reside? Our galaxy is about 100,000 light-years wide. We’re about 25,000 light-years from the center of the galaxy. It turns out we’re not located in one of the Milky Way’s two primary spiral arms. Instead, we’re located in a minor arm of the galaxy. Our local spiral arm is sometimes Orion Arm, or sometimes the Orion Spur. It’s between the Sagittarius and Perseus Arms of the Milky Way. The image below shows it.

Our sun is located the Orion Arm, or Orion Spur, of the Milky Way galaxy. It’s a minor spiral arm,
located between two other arms. Image updated in 2010 by R. Hurt on Wikimedia Commons.

Read more: Which spiral arm of the Milky Way contains our sun? | Space | EarthSky.

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