Newly Discovered Star Family Could Hold Clues to Milky Way Formation

A new family of stars was discovered at the core of the Milky Way galaxy, offering clues about the early stages of the galaxy's formation.

Astronomers from Liverpool John Moores University's (LJMU) Astrophysics Research Institute in the UK discovered the group of stars, which are called N-rich or Nitrogen-rich stars due to their unusually high levels of nitrogen. According to the scientists, the stars could provide insights on the origins of globular clusters, which are concentrations of millions of stars, formed at the beginning of the Milky Way's history.

"This is a very exciting finding that helps us address fascinating questions such as what is the nature of the stars in the inner regions of the Milky Way, how globular clusters formed and what role they played in the formation of the early Milky Way-and by extension the formation of other galaxies," Ricardo Schiavon, lead researcher from LJMU, said in a statement.

The stars were discovered during a collaborative project known as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), which collect infrared data from the night sky by capturing signatures of stars. While stars at the galaxy's core are typically shrouded by dust, Schiavon and his colleagues were able to use infrared star signals to see that there are an unexpectedly huge number of N-rich stars.

"The center of the Milky Way is poorly understood, because it is blocked from view by intervening dust. Observing in the infrared, which is less absorbed by dust than visible light, APOGEE can see the center of the Galaxy better than other teams."

As the newly discovered stars contain more nitrogen than the others around them, scientists suggest that they could have formed out of the remains of globular clusters - giant groups of millions of stars located at the "stellar halo" of the Milky Way, which formed during the galaxy's early days and then collapsed later on.

According to the study, which was published in the Monthly Notices of the Royal Astronomical Society, a better understanding of the newly found stars could shed light on how our galaxy and others like it have formed, which are among the most fundamental questions in modern astrophysics.

"Last, but not least, N-rich stars could be the oldest stars in the galaxy, the by-products of chemical enrichment by the first stellar generations formed in the heart of the galaxy," the team wrote in the paper.