An artist’s impression of a stream of stars left over from a globular cluster that was ripped apart by the Milky Way’s gravity. Image: Geraint F. Lewis and the S5 collaboration
Astronomers have found the remnants of a globular cluster that was ripped apart by the Milky Way’s gravity some 2 billion years ago. Spectral analysis of light from the globular’s spread-out remnants, known as the Phoenix Stream, shows they may be from a generation of globular clusters that formed in the very early universe, in a very different environment, than other known globulars.
“We were really surprised to find that the Phoenix Stream is distinctly different to all of the other globular clusters in the Milky Way,” said Zhen Wan of the University of Sydney, lead author of a study published in the journal Nature. “Even though the cluster was destroyed billions of years ago, we can still tell it formed in the early universe.”
The star stream is located in the southern Phoenix constellation and was observed using the Anglo-Australian Telescope in a project known as the Southern Stellar Stream Spectroscopic Survey Collaboration. The “S5” collaboration is focused on mapping the motion and chemistry of star streams in ...