Daily Bulletin

Men's Weekly

.

  • 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

Business News

How to Extend the Lifespan of Your Conveyor System

It’s easy to forget your conveyor is even there, until it stops. And when it does, you’re in a world of delayed orders, unexpected downtime, and one very expensive headache. But the good news is tha...

Daily Bulletin - avatar Daily Bulletin

Virtual CFO Hiring Checklist: 10 Expert Tips in Australia

Hiring a Virtual CFO (VCFO) is no longer just reserved for large corporations. In today’s business environment, where agility, compliance, and strategic foresight are essential, Australian startups...

Daily Bulletin - avatar Daily Bulletin

Top Mistakes to Avoid When Hiring Office Removalists in Perth

Moving a workplace is more than shifting workstations and computers; it is a complex project that can affect staff morale, customer service and revenue if it goes off-track. Perth’s commercial prope...

Daily Bulletin - avatar Daily Bulletin

LayBy Deals