The life cycle of star
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08/30/22 1 THE LIFE CYCLE OF STAR SOMETHING CHALLENGE VIDHATE G.B.
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Transcript of The life cycle of star
05/01/23 1
THE LIFE CYCLE OF STAR
SOMETHING CHALLENGE
VIDHATE G.B.
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Introduction OUR SCIENCE IS DISSCUSS ABOUT JUST
VISIBLE OBJECT ON EARTH. STAR HAS ALSO A LIFE. WHAT MEANT OF BLACK HOLE.
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Topics of Discussion LIFE CYCLE OF STARS.
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STARS
There are more stars than any other object in the universe.each is a spinning ball of hot,luminous gas.more stars are made mainly of hydrogen&helium.as these gases are convert to heavier elements, energy is produced.a star has a life cycle of billions of years that takes it through many changes.the mass of star,however,dictates how it will develop and die.
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* NUCLEOSYNTHESIS ** NUCLEOSYNTHESIS *
Chemical elements are created inside Chemical elements are created inside stars by nuclear reactions.The process stars by nuclear reactions.The process called nucleosynthesis,stars by called nucleosynthesis,stars by converting hydrogen to helium.A converting hydrogen to helium.A sequence of reactions at higher & higher sequence of reactions at higher & higher temperatures produces heavier & temperatures produces heavier & heavier elements.The heaviest produces heavier elements.The heaviest produces is iron.Most stars complete only part of is iron.Most stars complete only part of the process in their lifetime.the process in their lifetime.
Four hydrogen nuclei (called protons) Four hydrogen nuclei (called protons) are smashed together.Two positive are smashed together.Two positive particles escape,converting the two particles escape,converting the two protons into neutrons.protons into neutrons.
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# STAR BIRTH # Stars are created from clouds of gas and
dust.the cloud spins,and the material inside condenses and splits form smaller clouds. These in turn in spin and condense.each is proto star,a star in the making.once material in the core of a proto star has reached a creatical density and temperature,nuclear reactions start and energy is produced.The STAR is born.
Stars are shine due to the energy. IT MEANS STARS ARE CRAETED
FROM THE LARGE CLOUD.
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TYPES OF STARS There are two types stars. 1) Orion Nebula :- an interstellar cloud
of gas & dust producing new stars.left of center are four young & bright stars known as the trapezium.
2) Double stars :- About half the stars are in a double star system.both were created together from the same cloud of material & force of each other`s gravity keeps them together.
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! STAR CLUSTER ! STAR CLUSTERS :- Group of stars living
together are called clusters.A group may contain anything between a few or many thousand of stars,all created from the same cloud of gas & dust.the stars will be roughly the same age,but each develops in its own way.
Globular cluster(Hercules cluster):- older stars are densely packed in globular cluster which are spherical in shape.the Hercules globular cluster contains several hundred thousand stars.
Open cluster(Pleiades cluster) :- young stars loosely bound in open clusters & will disperse eventually.the stars in the Pleiades cluster are still surroundedby cloud material left over from their formation.
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! STAR DEATH ! After billions of years,a star uses up its
gases in the nuclear reaction taking place at its core.the star is starting to die ,but death can still be billions of years away.the mass of star dictates how it dies.A star like sun gradually shed material from its outer layers.one with eight times the sun`s mass can end its life in a gigantic explosion,called supernova because the explosion looks like a bright new star.
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# White Dwarf #Stars with less than eeight solar masses end their lives as white dwarfs.some of their material has been cast off;the rest condense to form a compact star about twice the size of earth.A match box of material from a white dwarf would weight as much as an elephant.
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Neutron Stars & PulsarAfter the massive star explodes as a supernova,gravity forces the core to collapse with incredible force.The material is so densely packed that it is compressed into Neutrons.The result is a neutrons star,perhaps only 10-15 km (8-12 miles) acrossPulsar are Neutron stars that spin rapidly,sending out beam of radio energy. A pin head of pulsar material would weight more than the biggest supertanker.
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