Tag Archives: milky way

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