Spiral Arms
Regions of stars and interstellar matter that extend from the center of spiral galaxies, forming a spiral pattern; in the Milky Way, these include the Orion Arm where our Solar System resides.
Source: esa.int
APODs including "Spiral Arms"
M83: The Southern Pinwheel Galaxy from VLT
06/12/1999
M83 is one of the closest and brightest spiral galaxies on the sky. Visible with binoculars in the constellation of Hydra, majestic spiral arms have prompted its nickname as the Southern Pinwheel. Although discovered 250 years ago, only in this century was it appreciated that M83 was not a gas cloud but a barred spiral galaxy much like our own Milky Way Galaxy. M83, pictured above in a recently released photograph from a Very Large Telescope, is a prominent member of a group of galaxies that includes Centaurus A and NGC 5253, all of which lie about 15 million light years distant. To date, six supernova explosions have been recorded in M83. An unusual double circumnuclear ring has recently been discovered at the center of M83 and is still being investigated.