Tag Archives: milky way

Milky Way not unusual, astronomers find

Detailed cross-section of another galaxy reveals surprising similarities to our home

The first detailed cross-section of a galaxy broadly similar to the Milky Way, published today, reveals that our galaxy evolved gradually, instead of being the result of a violent mash-up. The finding throws the origin story of our home into doubt.

The galaxy, dubbed UGC 10738, turns out to have distinct ‘thick’ and ‘thin’ discs similar to those of the Milky Way. This suggests, contrary to previous theories, that such structures are not the result of a rare long-ago collision with a smaller galaxy. They appear to be the product of more peaceful change.

And that is a game-changer. It means that our spiral galaxy home isn’t the product of a freak accident. Instead, it is typical.

Continue reading Milky Way not unusual, astronomers find

Not long ago, the centre of the Milky Way exploded

Researchers find evidence of a cataclysmic flare that punched so far out of the Galaxy its impact was felt 200,000 light years away.

An artist’s impression of the massive bursts of ionising radiation exploding from the centre of the Milky Way and impacting the Magellanic Stream.
Credit: James Josephides/ASTRO 3D

A titanic, expanding beam of energy sprang from close to the supermassive black hole in the centre of the Milky Way just 3.5 million years ago, sending a cone-shaped burst of radiation through both poles of the Galaxy and out into deep space.

That’s the finding arising from research conducted by a team of scientists led by Professor Joss Bland-Hawthorn from Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) and soon to be published in The Astrophysical Journal.

Continue reading Not long ago, the centre of the Milky Way exploded

Balloons over the Red Centre

A perfect view of the Milky Way

On a series of calm, cool mornings in April 2017, 70 French scientists (from the French space science agency CNES, CNRS IRAP, and the Université Paul Sabatier de Toulouse) launched three enormous balloons into the sky above the heart of Australia.

CNES was using the Alice Springs Balloon Launching Centre (ASBLS) to send three precision scientific instruments up to altitudes of 30–40 kilometres to make observations that are impossible from the ground.

Continue reading Balloons over the Red Centre

The Milky Way is warped

The first accurate 3D map of our galaxy reveals its true shape: warped and twisted.

Astronomers from Macquarie University and the Chinese Academy of Sciences have used 1339 ‘standard’ stars to map the real shape of our home galaxy in a paper published in Nature Astronomy today.

They found the Milky Way’s disc of stars becomes increasingly ‘warped’ and twisted the further away the stars are from the galaxy’s centre.

Continue reading The Milky Way is warped

Alice Springs—gateway to the stars

A BALLOON LAUNCH AT ALICE SPRINGS. CREDIT: R. SOOD.
A BALLOON LAUNCH AT ALICE SPRINGS. CREDIT: R. SOOD.

Scientists are using the unique advantages of Australia’s Red Centre to conduct high-altitude balloon flights for astronomical research. The clear air and low population of central Australia make it the ideal location for balloon-based research.

For most types of astronomy, observatories are typically built high on the tops of mountains, far out in space or high in the sky, dangling from 150-metre-tall helium balloons. Continue reading Alice Springs—gateway to the stars

Stellar immigration

DUNCAN FORBES IS IDENTIFYING ALIEN STARS. CREDIT: PAUL JONES.

If the Milky Way did grow by swallowing up smaller galaxies, then another team suspects it knows where in the Milky Way some of those alien stars are hiding.

Duncan Forbes of Swinburne University of Technology and his Canadian colleague Terry Bridges are using Hubble Space Telescope data to identify clusters of alien stars, using the fact that their age and chemical composition differs from their neighbours.

Continue reading Stellar immigration

Profiling and fingerprinting the stars

This story continues from Galactic archaeology— digging into the Milky Way’s past

RAVE PROJECT MANAGER, FRED WATSON, WITH THE UK SCHMIDT TELESCOPE. CREDIT: SHAUN AMY.
RAVE PROJECT MANAGER, FRED WATSON, WITH THE UK SCHMIDT TELESCOPE. CREDIT: SHAUN AMY.

But already, another Australian-led innovation in astronomical instrumentation is providing researchers with the critical information they need to understand the motions of stars within different parts of our galaxy, such as its main body, the bulging core, and the extended halo that surrounds it. Researchers are also searching for evidence of galactic cannibalism—swarms of stars that could be remnants of dwarf galaxies consumed by the Milky Way.

The innovation, called the 6dF instrument, is being used by a multinational consortium, the RAdial Velocity Experiment (RAVE), to measure the radial velocities of more than half a million stars. It is mounted on the Australian National University’s UK Schmidt Telescope at Siding Spring in New South Wales. Radial velocity is movement toward or away from the observer along the light of sight, as distinct from motion across the line of sight. The survey, which began in 2003, will be completed in 2011. Continue reading Profiling and fingerprinting the stars

Galactic archaeology— digging into the Milky Way’s past

ASTRONOMERS ARE HUNTING ‘FOSSIL’ STARS FROM GALAXIES DEVOURED BY THE MILKY WAY CREDIT: HUBBLE HERITAGE TEAM (AURA/STSCI/NASA/ESA)
ASTRONOMERS ARE HUNTING ‘FOSSIL’ STARS FROM GALAXIES DEVOURED BY THE MILKY WAY CREDIT: HUBBLE HERITAGE TEAM (AURA/STSCI/NASA/ESA)

Ken Freeman is hunting for fossils. But he’s not looking for old bones—he’s exploring the very origin and history of our Milky Way galaxy.

Conventional theory says that our galaxy grew big by engulfing smaller ones. If this is correct, stars from the original galaxies should be still identifiable within the main mass of stars via several tell-tale signs, from unusual velocities to spectral types. These stellar fossils would point to the galaxy’s birth and growth. Continue reading Galactic archaeology— digging into the Milky Way’s past

Bringing dark corners of the Universe to light

JOSS BLAND-HAWTHORN HOLDING A PHOTONIC LANTERN, A REVOLUTIONARY DEVICE TO ANALYSE THE LIGHT OF DISTANT STARS, INVENTED IN AUSTRALIA. CREDIT: CHRIS WALSH.
JOSS BLAND-HAWTHORN HOLDING A PHOTONIC LANTERN, A REVOLUTIONARY DEVICE TO ANALYSE THE LIGHT OF DISTANT STARS, INVENTED IN AUSTRALIA. CREDIT: CHRIS WALSH.

Using the Gemini South telescope in Chile, a team of astronomers led by Joss Bland-Hawthorn of the University of Sydney revealed the faint, outer regions of the galaxy called NGC 300, showing that the galaxy is at least twice the size as thought previously. The findings suggest that our own Milky Way galaxy could also be bigger than the textbooks say.

But Joss’s telescope observations are just a part of his contribution to astronomy. He is also helping to pioneer a new technology known as astrophotonics, which uses optical systems to improve our understanding of the Universe. Continue reading Bringing dark corners of the Universe to light