science ppt (1)

8/3/2019 Science Ppt (1)

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Science

Presentation

Topic : Stars And Constellations


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Stars Starsyou see thousands of them every timeyou look into the

night sky. Well, that is if you bother to even notice them. They aresort of

like trees, or houses; they are there every time you look, somost people take their presence for granted and never give them asecond thought. To help you understand what you are looking at inthe sky, here are a few fun facts about stars.

When you look into the night sky, all of the stars appear to bewhite, but they are not. Stars come in many colors: blue, brown,yellow, red, and orange to name a few. Within each of those colorsthere are several subcategories like giant and dwarf and a few waysto classify the age of a star.


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Stars create energy in one of two ways. The firstis converting h

ydrogen to helium in a proton-protonchain reaction basis(P-P) or the CNO cycle

(carbon-oxygen-nitrogen cycle)where they convertcarbon to nitrogen to oxygen to convert hydrogento helium(CNO cycle).

Our Sun is a single star. It stands alone near thevery center of our Solar System. That gives somepeople the impression that this is how things areevery where in the universe, but many stars occur

in groups. There are many binary(two) star systemsand some known to have as many as 6 in a system.


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constellations

A constellation is a group of stars that, when seen fromEarth, form a pattern. The stars in the sky are dividedinto 88 constellations.The brightest constellation is Crux(the Southern Cross). The constellation with the greatestnumber of visible stars in it is Centaurus (the Centaur -

with 101 stars). The largest constellation is Hydra (TheWater Snake) which extends over 3.158% of the sky.


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There are also asterisms, smaller apparent star

patterns within a constellation, like the Big

Dipper(in Ursa Major), the Little Dipper(in Ursa

Minor), Keystone (in Hercules), and

the Pleiades (in Taurus).

Big Dipper

Ursa Major

Pers

eus


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Orion the hunter Taurus


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The 12 Constellations of the Zodiac

The zodiac is a band of 12 constellations

along the ecliptic.Aquarius, the water bearer

Aries, the ramCancer, the crabCapricorn, the goatGemini, the twinsLeo, the lionLibra, the scalesPisces, the fishSagittarius, the archerScorpius, the scorpionTaurus, the bullVirgo, the virgin.


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questions

Will the stars appear to twinkle for an

astronaut who looks at them in space?

Ans: Stars are very far away from us

hence, appear as very tiny dots. The

light coming from them takes many

years to reach us. Also, the ray of light

bends when it enters the earthsatmosphere. Hence, the twinkling effect.


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What does CNO in the CNO cycle standfor?

Ans: carbon-nitrogen-oxygen How many constellations are there

belonging to the zodiac?

Ans: 12

Which is the largest constellation?Ans: Hydra, the water snake

There are how many known constellations?

Ans: 88

Are the stars white?Ans: No, they only appear to be white but are

in different colours like brown, yellow, orangeand more.


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bibliography

Info from class VIII science in everyday

life textbook, encyclopedia,

www.answers.com, wikipedia and

NCERT class VIII science textbook

Pictures from www.google.com


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contribution

Information and editing Mehak

Write-up Gunjan

Animation and beautification - Roweena


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Presented by :-

Mehak Roy

Gunjan mehlawat

roweena verma


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THANK YOU

science ppt (1)

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