Kent astronomer helps find 100,000 new stars

This previously unknown globular cluster, detected with the aid of the European Southern Observatory’s New Technology Telescope at La Silla, Chile, is about seven light years wide (slightly less than twice the distance between the Sun and its nearest star, Proxima Centauri) but contains approximately 100,000 stars for a total estimated mass of 65,000 times the mass of the Sun.

Star clusters provide scientists with unique laboratory conditions to investigate various aspects of astrophysics. They represent groups of stars with similar ages, chemical element abundances and distances. Globular clusters, in particular, are fossils in the Milky Way that provide useful information. With ages of about 10 billion years, they are among the oldest objects in our galaxy – almost as old as the universe itself. These massive, spherical shaped star clusters are therefore witnesses of the early, mysterious ages of the universe.

‘Moreover,’ says Dr Froebrich, who was also lead author of the paper presenting the team’s findings, ‘the properties of globular clusters are deeply connected with the history of their host galaxy.

‘We believe today that galaxy collisions, galaxy cannibalism, as well as galaxy mergers leave their imprint in the globular cluster population of any given galaxy. Thus, when investigating globular clusters we hope to be able to use them as an acid test for our understanding of the formation and evolution of galaxies.’

The finding is perhaps all the more significant in that only about 150 globular clusters within our galaxy are known, each containing many hundreds of thousands of stars.

The team is composed of Dr Dirk Froebrich (University of Kent), Dr Helmut Meusinger (Thüringer Landessternwarte Tautenburg, Germany) and Aleks Scholz (University of St Andrews).