Have you ever wondered how the stars remain in the sky without falling off? Or How far they are to the earth? Or what the size of a star might be if it was nearer to you? You are about to find out the answers to these questions and more. Read on!.
What is a Galaxy?
A Galaxy is a large system of stars, dust and gas bound together by gravitational force. It can be elliptical, spiral or irregular in shape. Our Sun is part of a spiral galaxy called the Milky Way. The Milky Way is the galaxy that contains our Solar System. Galaxies with less than a billion stars are considered “small galaxies.” In our own galaxy, the sun is just one of about 100 billion stars.
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What exactly is a Star?
A Star is a giant, luminous spheres of plasma held together by its own gravity.. There are billions of them — including our own sun — in the Milky Way Galaxy. And there are billions of galaxies in the universe.
How many Stars are there?
No one knows how many stars exist, but the number would be staggering. Our universe likely contains more than 100 billion galaxies, and each of those galaxies may have more than 100 billion stars. So it’s more like there is a star for every grain of sand on earth.
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How far are Stars to the Earth?
The Stars are actually millions of miles from Earth. Look at it this way, the Sun is the nearest star to the Earth (about 93 million miles away!) that’s why its so luminous on earth. There are uncountable stars in the Universe yet on a clear, dark night Earth’s sky reveals only about 3,000 stars to the naked eye. That’s because those are the ones near enough to be luminous on earth.
How big is a Star?
The Sun is an average star. Stars can be bigger than the Sun, and stars can be smaller. The smallest stars out there are the tiny red dwarfs. These are stars with no more than 50% the mass of the Sun, and they can have as little as 7.5% the mass of the Sun. There are over 200 billion galaxies in the known universe (a number that continues to grow), of which the Milky Way which contains our Solar System is the only one in which we can discern individual stars, so one cannot really say for sure how big a star can get.
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What determines the colour of a Star?
Although this coloured appearance of stars is not easily visible with naked eyes but if you look at them with telescope, you may easily get their coloured view. The surface temperature of a star determines the colour…………….Higher temperature means that the energy emitted is higher, which means that the wavelength of the light (on average) gets shorter i.e more blue while lower temperature means redder. Higher temperature stars are more massive in general while lower temperature stars are getting close to the end of their lives when they get really big.
Our Sun is yellow, so mid-mass star (hotter than some stars but certainly not the hottest). In about 5 billion years it will near the end of it’s life and grow much larger, and get cooler and therefore redder.
