ARC Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO-3D)

Star-quake vibrations lead to new estimate for Milky Way age

Data gathered by NASA’s now defunct Kepler telescope provides a solution to an astronomical mystery.

An artist impression of the Milky Way, showing the thick and thin discs.
Credit: NASA/JPL Caltech/R.Hurt/SSC

Star-quakes recorded by NASA’s Kepler space telescope have helped answer a long-standing question about the age of the “thick disc” of the Milky Way.

In a paper published in the journal Monthly Notices of the Royal Astronomical Society, a team of 38 scientists led by researchers from Australia’s ARC Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO-3D) use data from the now-defunct probe to calculate that the disc is about 10 billion years old.

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Spin doctors: Astrophysicists find when galaxies rotate, size matters

Sky survey provides clues to how they change over time.

A simulation showing a section of the Universe at its broadest scale. A web of cosmic filaments forms a lattice of matter, enclosing vast voids. Credit: Tiamat simulation, Greg Poole

The direction in which a galaxy spins depends on its mass, researchers have found.

A team of astrophysicists analysed 1418 galaxies and found that small ones are likely to spin on a different axis to large ones. The rotation was measured in relation to each galaxy’s closest “cosmic filament” – the largest structures in the universe.

Filaments are massive thread-like formations, comprising huge amounts of matter – including galaxies, gas and, modelling implies, dark matter. They can be 500 million light years long but just 20 million light years wide. At their largest scale, the filaments divide the universe into a vast gravitationally linked lattice interspersed with enormous dark matter voids.

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And then there was light: looking for the first stars in the Universe

Researchers hunt for a 12-billion-year-old signal that marks the end of the post Big Bang “dark age”.

In this image of the Epoch of Reionisation, neutral hydrogen, in red, is gradually ionizsed by the first stars, shown in white.Credit: Paul Geil and Simon Mutch

Astronomers are closing in on a signal that has been travelling across the Universe for 12 billion years, bringing them nearer to understanding the life and death of the very earliest stars.

In a paper on the preprint site arXiv and soon to be published in the Astrophysical Journal, a team led by Dr Nichole Barry from Australia’s University of Melbourne and the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) reports a 10-fold improvement on data gathered by the Murchison Widefield Array (MWA) – a collection of 4096 dipole antennas set in the remote hinterland of Western Australia.

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Anaemic star carries the mark of its ancient ancestor

Australian-led astronomers find the most iron-poor star in the Galaxy, hinting at the nature of the first stars in the Universe.

A visualisation of the formation of the first stars. Credit: Wise, Abel, Kaehler (KIPAC/SLAC)

A newly discovered ancient star containing a record-low amount of iron carries evidence of a class of even older stars, long hypothesised but assumed to have vanished.

In a paper published in the journal Monthly Notices of the Royal Astronomical Society: Letters, researchers led by Dr Thomas Nordlander of the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) confirm the existence of an ultra-metal-poor red giant star, located in the halo of the Milky Way, on the other side of the Galaxy about 35,000 light-years from Earth.

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