Modern Australian


Curious Kids: how are stars made?

  • Written by Orsola De Marco, Astrophysicist , Macquarie University
Curious Kids: how are stars made? If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au. How are stars made? –Zali, age 8, Karkoo, South Australia. How are stars made? Well, stars are not made, they make themselves! Or maybe I should say: they come into existence because of a powerful force of nature called gravity. Galaxies are where new stars are born. In galaxies, there are very large and fluffy clouds of gas and dust called nebulae. Gravity makes clumps inside these fluffy clouds - like raisins in a cake. When one of these clumps start to get tightly compacted and squished together, we say its density goes up. Density means how tightly something is compacted, or squished together. These dense clumps of gas also get hotter and hotter in the centre. When the gas in the centres of a clump reaches a certain temperature (millions of degrees), something quite special starts happening inside the clump: hydrogen atoms come together to form helium. (As I am sure you know, atoms are like tiny building blocks that make up everything around us. You, me and all the gas and space dust – it’s all made of atoms). Curious Kids: how are stars made? When hydrogen atoms come together to form helium, it’s called nuclear fusion, and a lot of energy is released. Shutterstock When hydrogen atoms come together to form helium, it’s called nuclear fusion. This process releases a lot of energy (it’s the opposite, yet similar process that happens when a nuclear bomb goes off). And this is how a star begins its life. Read more: Curious Kids: Why do stars twinkle? The life and death of a star Just like us, stars are born, they live and then they die. Curiously, the length of a star’s life depends on its birth weight. Light, low mass stars live very, very long lives. Our Sun, as you probably know, is actually a star. It is about 4.5 billion years old, and is in the middle of its life. In another five billion years it will get much, much bigger but then it will start to shrivel. After that, it will die. Its nuclear power source will switch off and it will just sit there, cooling, like a burnt out piece of charcoal in a barbecue. Stars that are many times heavier than our Sun live much shorter lives. The most massive stars, live for only a million years or so. Their deaths are much more spectacular than the quiet shrivelling of Sun-type stars. They go out in a bang. Scientists call them “supernovae”. Curious Kids: how are stars made? The dusty nebulae from which stars form live within the spiral arms of galaxies like this. By The Hubble Heritage Team (AURA/STScI/NASA)NASA Headquarters - Greatest Images of NASA (NASA-HQ-GRIN) - http://nix.larc.nasa.gov/info;jsessionid=1sl2so6lc9mab?id=GPN-2000-000933&orgid=12http://imgsrc.hubblesite.org/hu/db/images/hs-1999-25-a-full_tif.tif You’re made of star dust Have you ever heard the saying “we are all made of star dust?” It’s actually true. Inside a star, helium atoms combine to make carbon, which is at the root of chemicals that you and all living things are made out of. There is plenty we still do not understand about the mysterious lives of stars. Fortunately, we have large telescopes and space satellites to get better and better pictures. All we need is smart people like you to come and help figure out the puzzle! Read more: Curious Kids: can Earth be affected by a black hole in the future? Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au

Authors: Orsola De Marco, Astrophysicist , Macquarie University

Read more http://theconversation.com/curious-kids-how-are-stars-made-122787

NEWS

Hello, nostalgia: 5 reasons to start using film cameras again

While digital cameras have become increasingly advanced over the past few years, film photography is far from dead. Today, hobbyists and professional photographers alike are dusting off their old film...

let's understand what they mean before debating Australia's course

The current surge in community transmission of COVID-19 in Victoria has brought renewed discussion of whether Australia should maintain its current “suppression” strategy, or pursue an “elimination” strategy instead. But...

Can Australian businesses force customers to wear a mask? Here's what the law says

Loren Elliott/AAPMany Victorians are now being asked to wear a mask in public if they can’t socially distance. It is possible this practice may be encouraged more widely across Australia...

School is important, and so is staying safe from coronavirus. Here are some tips for returning seniors

ShutterstockVictorian senior students returned to school this week, as did those in specialist schools. This follows substantial community transmission of COVID-19, and stage three restrictions, in metropolitan Melbourne and the...

Humans are encroaching on Antarctica’s last wild places, threatening its fragile biodiversity

SL Chown, CC BY-NCSince Western explorers discovered Antarctica 200 years ago, human activity has been increasing. Now, more than 30 countries operate scientific stations in Antarctica, more than 50,000 tourists...

The Mukbang controversy is a chance to discuss race and Australian films. Let's not squander it

Eliza Scanlen’s film Mukbang (2020) has become a flashpoint in race relations in the Australian screen industry. Scanlen’s film is famous not for winning Best Director in the short film...

What does the 'new normal’ look like for women’s safety in cities?

ShutterstockWomen’s safety in public space is very complex. Women’s perception of safety – as opposed to their risk of experiencing gendered violence or crime – very much determines how they...

Government announces $2.5 billion package to support training and apprenticeships

Mick Tsikas/AAPThe Morrison government has announced $2 billion – to be augmented by another $500 million from the states – for a skills package to boost training and job creation.A...

Why not have an inquiry to examine the pros and cons of suppression versus elimination?

Scott Morrison on Wednesday once again ruled out any consideration of moving to an “elimination” strategy for dealing with COVID-19.He told Triple M Melbourne: “You don’t just shut the whole...

Lonely in lockdown? You're not alone. 1 in 2 Australians feel more lonely since coronavirus

Many Victorians are now well into their second round of stage 3 lockdown, under which there are only a handful of reasons one can leave home — and for many...

We could lose $30 billion in weeks from cyberwar. But the real loss is the erosion of public trust

The Australian Cyber Security Growth Network (AustCyber) on Monday released a report modelling the potential impact of cyberattacks and sustained digital outages on Australia.The Digital Trust Report’s modelling suggests four...

Is Australia ready for another republic referendum? These consensus models could work

The revelations in the “palace letters” may well renew enthusiasm for an Australian republic, especially coming on top of recent controversies involving both older and younger members of the royal...

Popular articles from Modern Australian

Every Thing You Need to Know Before Going to Aftershock FestivalCapture the Moment - Why it's so Important to Cherish the First Year of ParenthoodHow to supercharge your immune system for cold and flu season9 Reasons Sydney Is the Best Place to LiveWhat Do Pool Cleaners Do?ULTIMATE GUIDE TO STUDENT ACCOMMODATION6 Tips For Setting Up a Beautifully Functional Home NurseryPruning, What Is It And Are You Doing It Correctly?Fantastic Fishing Destinations Around AustraliaAre 4wd wheels expensive?What Actually Do Stamp Collectors Do?How to find affordable steel blue work boots in Australia for safety6 Ways To Get Quality Sleep When It’s HotThe Dangers of Uncontrolled High Blood Pressure7 Tips for Renovating a Heritage Home