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Our Starry Skies A star like the Sun
begins as a cloud of hydrogen gas and dust which is gradually
squashed by the forces of gravity and turns into helium gas to make
a star. This process produces huge amounts of energy.
Near the end of the life of a star, the helium changes into even
heavier substances. These giant stars eventually blow up in
huge explosions called supernovae. During these explosions
elements like carbon, silicon, iron and oxygen are scattered into
space. New stars and planets are created from this debris.
The biggest stars are called "red giants."
They have a lot of pressure in their core. Red giants burn
quickly and brightly and die earliest, leaving the core as a
"white
dwarf." Even our Sun will finally end its life as a tiny
"white dwarf" star.
Super-dense stars called neutron stars measure about 20
miles across. They spin quickly and send out radio
signals. The regular pulses picked up from these stars by
large radio receivers on Earth give them the name pulsars.
Eta Carinae is the brightest known star of all. It
is 150 times bigger than our Sun, and six million times brighter.
Sir Arthur Eddington (1882-1944) was the first person to realize
that the spiral shapes we see in the sky were galaxies. He
also proved that Einstein's theory of gravity was correct. He
was able to do this by observing light being bent during an eclipse
in the year 1919. Eddington wrote several famous books that
explained the nature of the universe. His books explain this in a simple and understandable way.
Check your local or school library for books by Sir Arthur Eddington
to learn more about the universe.
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