W.M. Keck Observatory | 2020 Oct 15
In a surprising discovery, astronomers using two Maunakea Observatories – W. M. Keck Observatory and Canada-France-Hawaii Telescope (CFHT) – have found a globular star cluster in the Andromeda Galaxy that contains a record-breaking low amount of metals.
The stars in the cluster, called RBC EXT8, have on average 800 times less iron than our Sun and are three times more iron-poor than the previous globular cluster record-holder. RBC EXT8 is also extremely deficient in magnesium. ...
A globular cluster is a large, dense collection of thousands to millions of ancient stars that move together as a tight-knit group through a galaxy. Until now, astronomers thought large globular clusters had to contain a considerable amount of heavy elements.
Hydrogen and helium are the two main elements created after the Big Bang. Heavier elements such as iron and magnesium formed later. Finding a massive globular cluster like RBC EXT8 that is extremely impoverished in metals defies current formation models, calling into question some of our ideas about the birth of stars and galaxies in the young universe. ...
Astronomers Discover Metal-Poor Globular Cluster
Netherlands Research School for Astronomy (NOVA) | 2020 Oct 15
An Extremely Metal-Deficient Globular Cluster in the Andromeda Galaxy ~ Soren S. Larsen et al
- Science (online 15 Oct 2020) DOI: 10.1126/science.abb1970