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The life cycle of star

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The document discusses the life cycle of stars from their birth in clouds of gas and dust to their death. As stars age, nuclear fusion in their cores produces heavier elements. Lower mass stars end as white dwarfs, while higher mass stars explode as supernovae, leaving behind neutron stars or black holes. Stars are found in clusters of varying densities and ages formed from the same gas clouds.

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08/20/15 1 THE LIFE CYCLE OF STAR SOMETHING CHALLENGE VIDHATE G.B.

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08/20/15 2 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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08/20/15 3 Topics of Discussion  LIFE CYCLE OF STARS.

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08/20/15 4 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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08/20/15 5 * NUCLEOSYNTHESIS ** NUCLEOSYNTHESIS *  Chemical elements are created insideChemical elements are created inside stars by nuclear reactions.The processstars by nuclear reactions.The process called nucleosynthesis,stars bycalled nucleosynthesis,stars by converting hydrogen to helium.Aconverting hydrogen to helium.A sequence of reactions at higher & highersequence of reactions at higher & higher temperatures produces heavier &temperatures produces heavier & heavier elements.The heaviest producesheavier elements.The heaviest produces is iron.Most stars complete only part ofis 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 positiveare smashed together.Two positive particles escape,converting the twoparticles escape,converting the two protons into neutrons.protons into neutrons.

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08/20/15 6 # 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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08/20/15 7 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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08/20/15 8 ! 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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08/20/15 9 ! 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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08/20/15 10 # 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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08/20/15 11 Neutron Stars & Pulsar After 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) across Pulsar 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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The life cycle of star

  • 1. 08/20/15 1 THE LIFE CYCLE OF STAR SOMETHING CHALLENGE VIDHATE G.B.
  • 2. 08/20/15 2 Introduction  OUR SCIENCE IS DISSCUSS ABOUT JUST VISIBLE OBJECT ON EARTH.  STAR HAS ALSO A LIFE.  WHAT MEANT OF BLACK HOLE.
  • 3. 08/20/15 3 Topics of Discussion  LIFE CYCLE OF STARS.
  • 4. 08/20/15 4 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.
  • 5. 08/20/15 5 * NUCLEOSYNTHESIS ** NUCLEOSYNTHESIS *  Chemical elements are created insideChemical elements are created inside stars by nuclear reactions.The processstars by nuclear reactions.The process called nucleosynthesis,stars bycalled nucleosynthesis,stars by converting hydrogen to helium.Aconverting hydrogen to helium.A sequence of reactions at higher & highersequence of reactions at higher & higher temperatures produces heavier &temperatures produces heavier & heavier elements.The heaviest producesheavier elements.The heaviest produces is iron.Most stars complete only part ofis 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 positiveare smashed together.Two positive particles escape,converting the twoparticles escape,converting the two protons into neutrons.protons into neutrons.
  • 6. 08/20/15 6 # 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.
  • 7. 08/20/15 7 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.
  • 8. 08/20/15 8 ! 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.
  • 9. 08/20/15 9 ! 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.
  • 10. 08/20/15 10 # 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.
  • 11. 08/20/15 11 Neutron Stars & Pulsar After 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) across Pulsar 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.