Are all the stars same?
No, Every star is unique. With the exception of the Sun, stars are all so far away from the Earth that they appear as pinpoints of twinkling light us. But even though they may look the same to the naked eye, they all have their own characteristics, differing in size, temperature, colour, and brightness, depending on how old they are.For example, hot blue-white stars can reach 54,000°F (30,000°C) at their surface, ten times hotter than the coolest stars. A supergiant star can be 600 million miles (1 billion km) across, but a neutron star is only the size of a city.
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| Arcturus Distance: 37 light years Brightness scale -0.05 |
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| Sirius Distance: 8.6 light years Brightness Scale -1.44 |
HOW DO STARS PRODUCE THEIR ENERGY?
Energy is produced in a star’s center, or core, where pressures are enormous and temperatures reach 27 million°F (15 million°C). This causes nuclear fusion—atoms of hydrogen are ripped apart and fuse (join) to form helium. These reactions release vast amounts of energy, which makes the star shine.
In the constellation Hercules is this cluster of hundreds of thousands of stars packed close together. Known as M13, it is a globular cluster. Globular clusters are found orbiting the center of our galaxy. Looser, open clusters of hundreds of stars are found in the galaxy’s spiral arms.
