DATA CONCERNING THE SUN
Characteristics Facts & figure
Shape Spherical
Size ( diameter ) 1.4 milion KM ( 109 x Earth’ s diameter )
Composition About 76% hydrogen, 22% helium, iron , nickel , silicon , and carbon make up the remaining 2% by mass.
Mass 1.989 x 10( 30) kg ( 330 000 x Earth’s mass )
Density 1.41 gcm (-3) ( compared with density of water )
Age About 4500 milion years
Distart from Earth 149 680 000 km
Gravitational force 28 x earth’s gravity
Surface temperature 6000 *C
Core temperature 1.5-2.0 milion *C
The structure of the sun and
its phenomena
CORONA :•OUTERMOST LAYER OF THE SUN•SENDS OUT X-RAY ENERGY AND LITTLE LIGHT•CAN ONLY BE SEEN DURING SOLAR ECLIPSE•TEMPERATURE IS EXTREMELY HOT 2 MILLION *C•STRETCHES OUT MORE THAN 1 MILLION KILOMETERS INTO SPACE
Photosphere•Visible surfaca of the sun •Temperature = 6000 *C •Heat, light are fron this layer•Sometimes, large magnetic disturbances may break throungh the photosphere and causes sunspots
Core •Made of hydrogen gas which turns into helium gas to produce light and heat by nuclear reactions•Temperature = 15 million*C
Chromosphere •Appears pinkish and can be seen by naked eyes only during solar eclipse•Temperature = 10 000*C – 50000*C•Active with various phenomena due to the various magnetic field
Effect s of the sun’s phenomena on the Earth
Interference in communication system :Satellite, telefon , computerTelegraph, radio, television
Influenced the climate and Weather of the Earth - Particularly extreme droughte
Causes an aurora-Sky near the poles appears- co lour fu l at n ight
The sun’s phenomena Radiate x-rays, ultraviolet rays, charged electric particles in the outer space
Burn ing parti c les In the atmosphere can d is rupt rad io waves
Generation Of Energe By The Sun
The sun’s energy generated from deep within the core of the sun Temperature and pressure : extremely highNuclear fusion takes place
Hydrogen helium
huge amount or energy
The energe generated is brought to the sun’s surface By convection and radiation Released as light ang heat
Intra – re
d
radiation SUN
THE SUN’S ENERGY
-Dries clothes-Kill microorganisms-Provides warmth
Warms and lights up The Earth
Green plants – make food By photosynthesis
Controls the earth’s Climate ( e.G cloud,Sterm, wind, rain,
Droughts)
Animals ( herbivor )- Obtain the sun’s -Energy indirectly by
eating the plants
Human use the solarenerge to generate
elecricity
Galaxies• Galaxies are giant structures that contain
hundreds of billions of stars, Oh, by the way…There are billions of galaxies in the universe
• Galaxies contain single stars, double stars, star systems and lots of gas and dust between the stars.
• Astronomers classify most galaxies into three main categories: – spiral galaxies, – elliptical galaxies, – irregular galaxies
Spiral Galaxies• Spiral galaxies have arms that spiral
outward, like pinwheels
http://zoo1.galaxyzoo.org/images/tutorial/example_face_on_spiral.jpg
http://www.spacetoday.org/images/Hubble/HubbleBeauty/NGC1512BarredSpiralGalaxy.jpg
The Milky Way• Our solar system exists in the Milky Way
galaxy, and is about 25,000 light-years away from the center of the Milky Way
• Our solar system is about two-thirds of the way out on one of the spiral arms of the Milky Way
• We can’t see the center of the Milky Way due to the massive cloud of gas and dust between the sun and the center
Elliptical Galaxies• Elliptical galaxies look like flattened
balls• Have little gas and dust between the
stars so new stars can not form– Ellliptical galaxies only contain old stars
http://photojournal.jpl.nasa.gov/jpegMod/PIA08696_modest.jpg
Irregular Galaxies
• Some galaxies don’t have a regular shape, they are called irregular galaxies
• The Large Magellanic Cloud is an irregular galaxy
http://www.nasa.gov/images/content/159426main_image_feature_666_ys_4.jpg
STAR
Characteristics Is a self-luminous
body
Made up of dust
and gases
We can see the stars - They give out light
Other objects ( meteors, comets, etc.) and planets are
dark and small- Can only be seen when
sunlight falls on them
Appear very small in the sky - Due to their distance from Earth
Most star exist in
pairs
The sun
Except
Lone star
Star
Classification
•Very a lot because of their saizes•A big star has a low density
•The smallest star : neutron star - 10 km in size• The biggest star :supergiant > 300 x sun’s size
•Can be determined by •analyzing its light •using a spectroscope•Main composition : hydrogen•and helium•Other elements : iron and carbon
•Depends on its surface •Temperature, sizes and distance from the earth•Brightest star: Magnitude – 26.5 (the sun)•Dullest star: magnitude +26.0 •The bright star can be seen by the naked eye ( e.g. sirius, rigel)
Brightness
Chemical composition
Size
Density
Relative sizes of stars
NEUTRON STAR
WHITE DWARF
THE SUN GIANT STAR SUPERGIANT STAR
Biggest star
Smallest star
TEMPERATURE AND COLOUR
B L U E WHITISH BLUE WHITE Yellowish
white
yellow orange red
> 30 000 *C 15 000 *C 11 000 *C 6 000 *C
5 000 *C 4 000 *C
Example of stars
3 000 *C
Lota Orionis Rigel SIRIUS Capella
Sun Arcturus Antares
f
Very large star Red giant Red supergiant
SUPERNOVA
Black hole
Neutron
Nebula : clouds of
gasesor dust Medium sized
star Red giantPlanetary
nebula White dwarf
Enormous clouds
of dust and gas in nebula
collapse under the force of gravity
The material condensed
and compressed by
the gravitational
force its temperature
begins it rise at its centre
As the temperaturerises, nuclear
fusion occurs in the core heat and
light energy travels out from
the centre. It glows and turns
into a star
The destruction
or star begins
when it has used up its
core hydrogen
fuel
The core will shrink and
heat up whereas the outer layers will expands
and cool down
CONSTELLATION
DEFINITION
A group of stars thatForms a certain
Pattern in the sky
IMPORTANCE
-To guide a navigators,ravellers or to find direction or locaion
Examples :
Identify the
periodof time
or season of the year
Identify and Locate the
stars
NAMED AFTER
•Some are visible at all times .•Some are seen at different times of the year. -Depending on the Earth’s orbit
Individuals in Greek orRoman
mythologye.g.
Andromeda, Perseus
Animals e.g.swan, bullHoroscope
Twelve of the Constellation
Form the zodiac
Astronomers have
recognised 88 constellati on
Twelve of the constellation from the zodiac
Aquarius Libra
Aries Sagittarius
CANCER Virgo
Gemini
Scorpion
Capricorn PISCES
Taurus Leo
25,000 lightyears
1000,000 lightyears
The sun and otherStars forms a galaxy;
Milky way
SIDE VIEW
The Sun and its planets formthe Solar System
•The galaxy where our solar system is formed •Consists of about 10 billion stars •The nearest galaxy : The Magellan Cloud•The nearest galaxy : Proxima Centauri•It is a spiral galaxy
Milky way
TYPES OF
GALAXY
Irregular galaxy•Have not formed specific shape•Consists mainly of young stars•Example : Magellan Cloud
Elliptical galaxy- Flattened, ball shape - Consists mainly of old stars - cannot form new stars- Does not contain any more dusts and gas- Example Galaxy M87 in Virgo
IRREGULAR GALAXY
Elliptical galaxy
Spiral galaxyDisc-shape, have
spiral armsConsists of old
and young stars- Older stars :
centre-Younger stars : at
the edges-Examples : Milky way, Andromeda
SPIRAL GALAXY
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