Huge new dataset reveals chemical data on 600,000 stars

Researchers are excited by the astronomical questions that can now be answered following the release of ‘GALAH DR3’, the largest set of stellar chemical data ever compiled.

The data, based on over 30 million individual measurements taken over several years, was gathered by an Australian-led team of astronomers, including researchers from The University of New South Wales (UNSW Sydney) and the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), using the Anglo Australian Telescope (AAT) at Siding Spring Observatory in rural New South Wales.

The release is the third from the Galactic Archaeology with HERMES (GALAH) project, which aims to investigate this history of star formation, chemical enrichment and galaxy mergers in the Milky Way. The new data measures 29 chemical elements in 600,000 stars and takes the project closer to meeting its goal of surveying one million.

‘Making large datasets like GALAH DR3 widely available is really important for astronomical research,’ explains Associate Professor Sarah Martell, who is a former ARC Discovery Early Career Researcher Award (DECRA) recipient from UNSW and an affiliate member of ASTRO 3D.

‘Since the start of the GALAH project, we have focused on building a dataset that can answer our questions about the history of the Milky Way, and also many others. I'm excited to see what our international colleagues will do with GALAH DR3.’

The GALAH project’s previous data release – known as DR2 – took place in 2018. It has fuelled a raft of significant discoveries regarding the evolution of the Milky Way, the properties of exo-planets, and hidden star clusters.

The ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions is administered by The Australian National University

	More than 100 scientists are collaborating on the galah project, based at universities in Australia, New Zealand, Italy, UK, Slovenia, US, Hungary, Sweden, the Netherlands, and Germany.