The cosmos never fail in conspiring different ways to amaze us and make us wonder about its different beautiful aspects.
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| A nebula - the blue lights are the stars that are forming |
About 13.5 billion years ago, when our universe didn't take shape that we observe today, there was only gaseous Hydrogen of a nebula from which it was formed. Hydrogen is lightest of all the elements that can be found anywhere. These atoms of hydrogen, or the tiny mass-points, were pulled together by gravity - a force that manifests itself fully with increasing mass. These clusters of mass-points produced hydrogen-clouds. Gradually with increasing conglomeration of more Hydrogen atoms; the gravity increased followed by rise in temperature. The process repeats itself time and again until a massive central core is formed with high density and temperature. The energy of the particles that are pushed towards the centre of the nebula gets converted into heat energy, thereby, increasing the temperature of the core of the nebula. Finally, a temperature of about 10million degrees is reached; when accidentally by the process of nuclear fusion, the Hydrogen at the core gets converted into the next heavier element - Helium. This nuclear reaction is followed by further rise in temperature and the energy is radiated in the form of heat and light. This is how a star is born. This is a thousand times bigger than our sun and is deep blue in colour.
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| The star that is born |
Helium being heavier than Hydrogen sinks down to the centre of the star, the layers of Hydrogen outside the core provides the fuel required to continue the nuclear fusion process at the centre. These hydrogen-clouds are further used up by the core to produce more Helium and the process is repeated time and again. The mass of the core increases, gravitational pull increases, further increasing the temperature. At such a high temperature, the Helium atoms fuse together forming heavier elements like Carbon(a vital element found in every living thing) and Oxygen. This process of fusion goes on repeating to produce different elements of heavier mass and finally Iron is formed. Now, this iron cannot undergo any fusion reaction further to produce heavier elements. The star which was increasing in size and temperature becomes gigantic and glows with a red colour. This is then called a Red Giant.
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| Red giant |
While the gravitational forces tend to contract the star, the energy released by nuclear fusion taking place at the centre; pushes the matter out. An equilibrium is reached when these two opposing forces balance each other. Then the size of the star remains constant for almost a few billion years.
At a time when all the surrounding Hydrogen are used up in the core and the star is mostly made of Iron, the nuclear furnace at the centre stops and the equilibrium is lost. Gravity now takes over - squashing all the Iron and other elements that were produced at the centre. This process is accompanied by increase in density as well as rise in temperature to about 100 times the core of our sun! Finally the star collapses and explodes, giving out enormous amount of light - a process called 'death of the star'. The exploding star throwing out large amount of matter and light in the space is a visual treat and is called a Supernova.
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Hubble Space Telescope image showing Supernova 1994D in galaxy NGC 4526 |
From the remnants of this explosion some of the most valued elements are formed! This explosion, for a brief microsecond, forces the Iron to fuse to produce heavier elements - like Gold, Platinum, Lead. So in a way, they are forged in the heart of an exploding star at its time of death!
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| A chunk of Gold |
So, if you have a gold ring; make sure you appreciate it. The metal was built in a blinding flash of light billions of years ago!
