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.
This story continues from Galactic archaeology— digging into the Milky Way’s past
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
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
Advanced telescopes need advanced astronomers to run them. Australia is matching the millions of dollars it is investing in new telescope technology with funds to help train the rising stars of Australian astronomy.
“We’ve had big investments in infrastructure, and now we need young scientists with the expertise to use them,” says Elaine Sadler, professor of Astrophysics at the University of Sydney and chair of the National Committee for Astronomy.
One new tranche of research funding for early career astronomers comes in the form of three-year Super Science Fellowships from the Commonwealth Government. In 2011, 14 young astronomers became Super Science Fellows, joining the 17 who started work in 2010. All up, astronomy will receive one-third of the Federal Government’s $27 million commitment to the Fellowships program. Continue reading Nurturing super astronomers at home
You have to be well prepared, quick and lucky to take a picture of an explosion, especially if that explosion occurred 11 billion years ago in a remote part of the Universe. Having the right equipment, plus friends in high places, certainly helps. And that’s exactly what the Zadko Telescope—managed by the University of Western Australia at the Gingin Observatory about 70 kilometres north of Perth—does have.
In December 2008, just after it was installed, the telescope was first on the scene to record for future analysis the afterglow of a momentous event—a huge explosion as a star collapsed into a black hole releasing a massive gamma-ray burst. It’s the kind of happening the one-metre Zadko Telescope, currently the largest optical telescope in Western Australia, was built to observe. And it performed flawlessly, outpacing the world’s most powerful telescopes at the European Southern Observatory in Chile.
Cracking the puzzle of unusual molecules in deep space that absorb some wavelengths of starlight is like unlocking the secrets of the Rosetta Stone, according to Rob Sharp of the Australian National University’s Research School of Astronomy and Astrophysics. “It’s the longest-standing problem in astronomical spectroscopy,” he says.
The identity of the molecules has been a mystery for 80 years, but Rob has now joined forces with chemists at the University of Sydney to try to crack the molecular code. Continue reading Is the Red Rectangle a cosmic Rosetta Stone?
Imagine an extremely large optical telescope fitted with detectors that can selectively collect light from a particular section of the telescope’s focal plane. Using revolutionary robotic technology called Starbugs, the detector will reconfigure itself in real time to collect from any particular area of the image, and will feed the data into any analytical instrument.
That’s exactly what Matthew Colless and his team at the Australian Astronomical Observatory have in mind with the development of MANIFEST (the many-instrument fibre system)—which make use of the special photonic technologies developed by Joss Bland-Hawthorn and his team at the University of Sydney. Continue reading Sifting sky data
Stars forming in clusters from a single galactic dust cloud are not as similar to one another as previously thought, according to an international team of astronomers who analysed ‘starquakes’ from just three months of data from NASA’s Kepler space telescope. And there is at least another four years’ data to come.
“In the past, it was assumed that the only difference [between stars in the same cluster] would be their mass,” says Dennis Stello of the University of Sydney. “But the seismology [data] tells us that might not be correct. There’s probably a spread in age or in composition because the original cloud of gas was not homogeneous.” Continue reading Starquakes reveal family secrets
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
When the present upgrade is complete, the Sydney University Stellar Interferometer (SUSI) will be able to resolve objects the size of a beach ball on the Moon, says Mike Ireland of Macquarie University in Sydney. This large interferometer will be used to determine the dimensions—size, weight and velocity—of pulsating stars, hot stars, and massive stars. SUSI will also be involved in the search for binary stars and their planetary companions. Continue reading Seeing a beach ball on the moon