A single frame from an animation shows how stellar orbits in the Milky Way can change. It shows two pairs of stars (marked as red and blue) in which each pair started in the same orbit, and then one star in the pair changed orbits. The star marked as red has completed its move into a new orbit, while the star marked in blue is still moving.
Dana Berry / SkyWorks Digital, Inc.; SDSS collaboration
A new map of the Milky Way has revealed a surprising fact about the stars living in our galaxy — nearly a third have moved far from their stellar birthplace.
This discovery was made by astronomers using the Sloan Digital Sky Survey-III (SDSS), which spectroscopically linked chemical elements in stars with the locations within our galaxy known to be abundant in those specific elements. And it turns out that 30 percent of the stars surveyed have migrated far from home.
“We were able to measure the properties of nearly 70,000 stars in our galaxy for this particular study using the innovative SDSS infrared spectrograph,” Donald Schneider, of Penn State University, Pa., and study coauthor, said in a press release. “This exercise can be described as galactic archaeology. These data reveal the locations, motions, and compositions of the stars, which provide insights into their formation and their history.”
The researchers leveraged data from the SDSS Apache Point Observatory Galactic Evolution Explorer (APOGEE) to map the quantities of 15 different elements (including carbon, silicon and iron) found in the sample of stars located throughout the galaxy. They found that 30 percent of the sample contained quantities of these elements that wasn’t typical for the location of the galaxy they were found in, meaning they had moved a long way from where they were born.
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