Name: Syafiqah Lyana binti Shamsuri

Form: 2 Jujur (2007)

Chapter: Sun and Galaxies (9)

Density:about

1500 kg/m3

Diameter:about

1 400 00 km = 100 x the

Earth diameter

Mass:

1.99 x 1030

kg

Temperature:Surface-6000CCentre of the

Sun-15 000 000C

Produces a strong gravitational forces = about 28 times greater than the gravitational force produces by the

Earth

•Middle layer•Can only be seen during an eclipse•The temperature about 15 000C

•Outermost layer•Extends hundreds of kilometers from the centre of the Sun•The temperature can reach 2 000 000C

•Surface of the Sun•About 500km thick•Consists of dense gases•The temperature is about 6000C

ProminencesThrow out matter from the Sun into space at speeds from 600km/s to more than 1000km/sLast for a few days or even for a few month

SunspotsDark areas on the SunsCooler than the surrounding areasMay last for more than a week

Solar Flares violent and spectaculars gas explosion that often occurs near sunspots made up of numerous charged gaseous particles from the Sun shooting outward at high speed into outer space interact with Earth’s magnetic field producing dazzling light display called aurora

Aurora Borealis,

(northern light)

Aurora Australis,(southern

light)

Composition of Sun is helium and hydrogen Because of the temperature, thermonuclear reactions occur in the Sun’s core @ Release large amount of heat and light energy

Temperature reach 15 000 000 C Energy from the core is distributed by the processes of radiation and convection Sun energy is emitted as electromagnetic waves

Star with mass <1.4 x Sun’s mass

Star with mass >3 x

Sun’s mass

Star with mass 1.4 to 3.0 x Sun’s mass

The diagram above shows the formation and death of stars Stars begin as a large cloud of gas and dust called nebula After ten thousands of year collapse, a hot core will be formed When the supply of gas in a star runs out, the star dies

When a star with a mass of up to 1.4 times the Sun’s mass, it’s will become a red giant The red giants then contracts, releasing its gas and turns into white dwarf

When a star with mass of between 1.4 and 3.0 times the Sun’s mass, it will become red giant then continues swell even more to become supergiant The supergiant then explodes producing supernova As the supernova collapse, a neutron star is formed

When a star with mass of more than 3.0 times the Sun’s mass, it swell up become red giant then become supergiant The supergiant then explodes producing supernova As the supernova collapse, its core becomes so massive that its gravity sucks everything including light into it The core is called a black hole

Stars are grouped together in vast collections called galaxies Our Solar System with only one star, the Sun, forms a tiny part of galaxy called the Milky Way Galaxy are classified into various type based on the shaped. Three common types of galaxies are spiral, elliptical and irregular shaped

Large galaxy with 20 000 to 100 000 light years of Diameter Disc-shaped with @ centre : older stars @ spiral arms : new stars, gases and dust 30% of galaxies are spiral

Diameter of galaxy is3 000 to 10 000 light years Smooth and rounded or oval in shape Brightest at the centre and fades towards the edge Consists of mainly old Star 60% of galaxies are elliptical

Diameter of this galaxy is 25 000 to 32 000 light years No definite shape and exists in various forms Consists of bluish-white stars (young star) and nebulae 10% of galaxies are irregular

A spiral-shaped galaxy with a diameter of 100 000 light years and is about 10 000 light years thick Consists of old stars at the centre at the center and nebulae (dust and gases) at spiral arms Stars in Milky Way galaxy are so close together and observed as hazy patches The Sun is 30 000 light years from the center of Milky Way The Sun takes 200 million years to orbit the centre of the Milky Way

Main Source of Energy

Sunlight is essential for photosynthesis

Causes water to evaporate• produces rain

Calendars based on phases of the Moon

Affect the occurance of ocean tidal

Encourage the development of technologies based on the Moon travelling

Nobody knows exactly how the Universe began or how it will end. Among the various scientific theories about the formation of the Universe, the most widely accepted scientific theory is the Big Bang theory

According to the Big Bang theory, about 12 billion to 15 billion years ago, our Universe began with enormous explosion. Since then, the Universe has forever been expanding everywhere at the same time