University of Warwick | 2018 Jun 04
Globular clusters could be up to 4 billion years younger than previously thought, new research led by the University of Warwick has found.
Binary star evolution within a globular cluster -- © Mark A. Garlick/Univ of Warwick
Comprised of hundreds of thousands of stars densely packed into a tight ball, globular clusters had been thought to be almost as old as the Universe itself - but thanks to newly developed research models it has been shown that they could be as young as 9 billion years old rather than 13 billion.
The discovery brings into question current theories on how galaxies, including the Milky Way, were formed - with between 150-180 clusters thought to exist in the Milky Way alone - as globular clusters had previously been thought to be almost as old as the Universe itself.
Designed to reconsider the evolution of stars, the new Binary Population and Spectral Synthesis (BPASS) models take the details of binary star evolution within the globular cluster into account and are used to explore the colours of light from old binary star populations - as well as the traces of chemical elements seen in their spectra. ...
Reevaluating Old Stellar Populations - E R Stanway, J J Eldridge
- Monthly Notices of the RAS (online 24 May 2018) DOI: 10.1093/mnras/sty1353
arXiv.org > astro-ph > arXiv:1805.08784 > 22 May 2018