Brisbane Times - Brisbane Australia
Breaking news from Brisbane & Queensland, plus a local perspective on national, world, business and sport news.
Galactic ring of fire gives scientist clues about the early universe - Brisbane Times
Australian astronomers have found evidence of a colossal collision in the infancy of the universe which sheds new light on how galaxies form.
"What weve discovered is incredibly rare, because you need specific conditions for this to form - it has to be a very thin disc made of stars and you need something else to collide with it head on," Dr Yuan said. The actual composite image of the galaxy compiled from multiple passes with the Hubble Space TelescopeCredit:Tiantian Yuan/Hubble Space Telescope "Imagine you throw a pebble into a pond at a sharp angle, it wont be nice rings, youll get splashes. So this is a very elegant collision." The resulting hole a diameter 2 billion times longer than the distance between the Earth and the Sun. Dr Yuan said they had even managed to find the culprit - a second, denser galaxy that punched right though the thin disc. "We were able to confirm the existence of the 'intruder' galaxy as they are known," she said. "We can calculate how far away that galaxy is, how fast it punched through the other galaxy. Its like catching the criminal in action." The ring galaxy is 11 billion light years away from Earth, which means it was formed just a few billion years after the universe itself formed in the Big Bang about 13.8 billion years ago. Dr Yuan said this was an important finding, as it had previously been considered too early in the universes formation for such a thin disc of fully formed stars to have been present. "What weve found is that in order to have that hole in it, the thin disc needed to have formed before the collision," she said. "And that means that at an early stage in the universe, just a few billion years after the big bang, we are already seeing thin-disc galaxies." Research co-author, Professor Kenneth Freeman from the Australian National University, said the findings give astronomers a clearer picture of the early universe. "The thin disk is the defining component of spiral galaxies: before it assembled, the galaxies were in a disorderly state, not yet recognisable as spiral galaxies." "This discovery is an indication that disk assembly in spiral galaxies occurred over a more extended period than previously thought." "For comparison, the thin disk of our Milky Way began to come together only about 9 billion years ago." The research findings have been published in the journal Nature Astronomy. Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.
Brisbane to shiver through coldest May day in years - Brisbane Times
A top of just 19 degrees is predicted for Brisbane on Saturday, one degree shy of the monthly record set in 2013, as temperatures drop below average statewide.
Minimum temperatures will also dip about five-to-eight degrees below the May average, with Brisbane to manage just 9 degrees on Sunday morning. "Many locations about the east and north-east coast are likely to approach and possibly even break their May records for the lowest maximum temperature ... on Saturday," Ms Pattie said. The cool change is the result of thick cloud cover which was restricting heating, along with rain falling into a dry subsurface layer across some regions. "That acts kind of like an evaporative airconditioner," Ms Pattie said. Some areas around Brisbane and the south-east recorded between 10 and 24 millimetres from Thursday into Friday morning. Real-time bureau data showed much of the region sitting below 20 degrees on Friday afternoon, with an apparent temperature of just 13.5 degrees in Brisbane at 3pm. The bureau has issued a sheep graziers warning for the Darling Downs, Granite Belt and parts of the Maranoa, Warrego and Central West on Saturday. A similar risk to livestock will impact the north of the state from Friday. Between 50 and 100 millimetres fell in the region between Cairns and Ingham in the 24 hours to Thursday morning, with isolated totals approaching 300 millimetres.
Aussie astronomers tune into the beat of teenage stars for first time - Sydney Morning Herald
A group of astronomers has identified that a cluster of teenage stars have their own beat, which they've managed to tune into for the first time.
Its like a piano with many notes being played - each note is fine, but when you put them all, together there was no pattern. The researchers managed to single out 60 stars from the cluster which seemed to have more regular pulsations, and from them learned why so many of the others seemed to be off-beat. The pulsating delta Scuti star, beta Pictoris, 60 light years from Earth, was part of the study The reason the other stars are different is because theyre rotating quite rapidly. To compare, our sun rotates about once a month, these stars are rotating every day or so, which is very fast, Professor Bedding said. That rotation is so fast that the star is no longer spherical, but its squished into an oval shape and that affects the pulsations quite a lot. The effect is compounded, the researchers discovered, by the angle at which we on Earth are viewing the rapidly spinning star. The research team was able to gain new insight into the stars themselves by using NASAs Transiting Exoplanet Survey Satellite (TESS), which was set up to find planets orbiting distant stars, but which is also useful in getting a close look at unusual stars such as the delta Scutis. University of Sydney astronomer, Professor Tim Bedding (right) with PhD student Isabel Colman, The findings will add to the depth of knowledge in the burgeoning field of asteroseismology, which looks at things like the pulsation of stars to give insight into their makeup, how old they are, and how they function. For example measuring the ages of stars is very difficult, they dont come with use0by dates on them. If you look into the sky how do you know how old a given star is? Professor Bedding said. There are ways to tell, but this method is particularly accurate, providing you can identify the pulsations youre seeing. The team discovered that almost all the stars in the cluster, which range from 60 to 1400 light years away, were juvenile stars of up to 100 million years old. These stars are young enough that we can see theyre still hanging around in their groups from when they were formed, Professor Bedding said Our own sun is about 4.5 billion years old, we have no idea whether it was born alongside other stars that have since dispersed to other parts of the galaxy. Isabel Colman, a co-author and PhD student at the University of Sydney, said it was exciting to be able to work on the cutting edge of a new field in astronomy. Some of the stars in our sample host planets, including beta Pictoris, just 60 light years from Earth and which is visible to the naked eye from Australia, she said. The more we know about stars, the more we learn about their potential effects on their planets. The research has been published in the journal Nature. Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.