STARS.

What is a star?

What is a star?

• If you look up at the night sky, you will see lot of stars but what is a star,.
• A star is a ball of hydrogen and helium with enough mass that it can sustain nuclear fusion at its core
• 75% is hydrogen and 23% is helium in the universe.. Thats left from the Big bang.
• These elements exist in large stable clouds of cold molecular gas. At some point a gravitational
• Disturbance,like a supernova explosion will cause a cloud of gas to collapse,begining the process of a star formation.

WHAT'S THE DIFFERENCE BETWEEN THE SUN AND THE OTHER STARS .

• The main difference between our sun and the other stars is that
• The sun is closer to Earth then any other star.
• Other differences are the mass,size temprature and age.
• About one hundred stars are more than eight times the size of our sun.
• The bigger the star, the shorter life, And some old stars are even smaller then Earth.

HOW DOES A STAR LOOK LIKE?

• The stars in the sky can appear to be different colors
• Because their temprature are not all equal.
• Hot stars are white and blue while coolder stars appear to have
• Orange and red hues.

FACTS.

• Our universe is likely to contain
• More than 100 billion galaxies,and each of these galaxies
• Can have more than 100 billion stars.
• Most stars are between 1 billion and 10 billion years old.
• The oldest star that have been discovered is 13.2 billion years old.

FACTS.2

• Some stars are 600 000
• Times as bright as our sun.
• Every star would explode if the gravity did
• Not hold its material together.
• Stars that have really strong gravity become smaller and smaller.

FACTS.3

• If you look at the night sky far from city lights,
• You can se about 3000 stars without using a telescope.
• Some stars are so far away that when the light finally reaches you
• It has already taken a million years,and the star may already be gone when
• You finally see it's brilliant light.

What is the biggest star in the universe?.

• http://youtu.be/wtSNDjDw6fI
• 0:00-3:02.

MY SOURCES ARE.

• Science.nationalgeographic.com.
• Www.Windows2.universe.org.
• Www.universetoday.com.