The Stars That Time Forgot: Remnant of Strange Dismembered Star Cluster Discovered at Galaxy’s Edge
Led by PhD student Zhen Wan and his supervisor Professor Geraint Lewis, an international team of astronomers has found a shredded globular cluster on the edge of the Milky Way, the remnant of a type of ancient structure that no longer exists.
An international team of astronomers has discovered the remnant of an ancient collection of stars that was torn apart by our own galaxy, the Milky Way, more than two billion years ago. The extraordinary discovery of this shredded ‘globular cluster’ is surprising, as the stars in this galactic archaeological find have much lower quantities of heavier elements than in other such clusters. The evidence strongly suggests the original structure was the last of its kind, a globular cluster whose birth and life were different to those remaining today. Our Galaxy is home to about 150 globular clusters, each a ball of a million or so stars that orbit in the Galaxy’s tenuous stellar halo. These globular clusters are old and have witnessed the growth of the Milky Way over billions of years. The study, published in Nature, was led by University of Sydney PhD student, Zhen Wan, and his supervisor, Professor Geraint Lewis, as part of the S5 international collaboration.
Using the Anglo-Australian Telescope in outback New South Wales, this collaboration measured the speeds of a stream of stars in the Phoenix constellation, revealing them to be remnants of a globular cluster that was pulled apart by the gravity of the Milky Way about two billion years ago.
Mr. Wan said: “Once ...
More on: scitechdaily.com