13ODiameter 863,746 miles (1,390,000 km)
OMass (Earth=1) 330,
OCore temperature 27,000,032°F
(15,000,000°C)
ODistance from Earth
93,000,000 miles (150,000,000 km)
The Sun is our nearest star.
Without the Sun, the Earth
would be frozen and lifeless.
The Sun was born in a cloud of
gas and dust about 4.6 billion
years ago and is now halfway
through its life.
The Sun
Brown dwarf
(right) with a
nearby orbiting
object (red).O Betelgeuse, a red supergiant, is about
700 times the size of the Sun.
O Neutron stars are only about 12 miles
(20 km) across, but so heavy that one
teaspoonful would weigh a billion tons.
O Brown dwarfs are stars that weren’t
hot enough for nuclear reactions to begin.FACT FILE
SPACETHE SUN
The Sun is a yellow dwarf, a fairly
ordinary star made mainly of
hydrogen. Hydrogen is changed
to helium at its center (the core).
When this happens, huge
amounts of radiation are released.Huge plumes of hot gas
sometimes stream away
from the Sun. They are
called prominences.7 /^7
O Planetary nebulas Small stars expand to become red giants.
When they run out of fuel they collapse. Their outer layers are
puffed out in rings called planetary nebulas. Each star creates
a different shape, such as a cat’s eye (below), a butterfly, or a
ring. The central star shrinks to a tiny, hot white dwarf.O Supernovas When big stars run out of fuel, they collapse.
Their outer layers explode into space in a supernova (right).
These can briefly outshine an entire galaxy, but are rare
events. The photograph on the left shows the same star ten
days before a supernova. Medium-sized stars become neutron
The Cat’s Eye Nebula is made up of many gas clouds ejected by a stars. Massive stars create black holes.
dying star.Before AfterSTAR DEATH
The color of a star is a guide
to its surface temperature.
The hottest stars are blue or
white, stars like the Sun are
yellow, and cool stars are
orange or red.(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.