Life Cycle of a Star Life Cycle Stars
- Slides: 14
Life Cycle of a Star Life Cycle: Stars are like humans. They are born, live and then die.
_______ Interstellar Medium _______ is the total mass of the gas and dust between the stars.
NEBULA _______: A dense cloud of gas and dust
The nebula begins to contract due to _____ and the pressure and temperature gravity PROTOSTAR increase and becomes a ________.
When the temperature gets hot enough, ________ fusion begins and a ____________ star is born. MAIN SEQUENCE
A star loses ______ mass during fusion as energy is released. This decreases the star’s gravity. A star will expand, becoming a ____________, when RED GIANT fusion the outward force of ________ is greater than gravity the inward force of _______.
fusion As the fuel runs out in a star, _____ slows down. When the _______ force of fusion is less than the ______ outward inward force of gravity, the star will shrink in size, becoming a WHITE______. DWARF _____ White Dwarf A ______ PULSAR is a rotating white dwarf emitting radio waves.
SUPERNOVA explosion A __________ is an _________ that marks the end of a very massive star’s life. When it occurs, the exploding star can outshine all of the other stars in the galaxy in total for several days and may leave behind only a crushed core.
The life cycle of stars depends on their mass. Small and medium stars become BLACK _________ DWARVES once they die. Larger stars become novae and die as: ______ NEUTRON STAR A neutron star is an imploded core of an exploded star made up almost entirely of neutrons. A teaspoon of their material would weigh more than all of automobiles in the U. S. together The most massive stars become supernovae and die as: ___________ BLACK HOLE A black hole is an extremely massive remnant from which light can not escape http: //chandra. harvard. edu/photo/2004/rxj 1242/index. html
Why do larger/hotter stars burn their fuel faster and live shorter lives than the Sun. Large, more massive stars have much more _______ gravity than the sun. This greater internal pressure causes fusion reactions to occur _____. This causes the largest stars to burn their quickly fuel, and eventually run out, much more _______. lives Larger stars live shorter _______. Bigger stars are brighter and hotter due to the rapid rate of fusion _____.
Where do we get the elements? ? All stars spend the majority of their lives fusing _____ the main hydrogen into ________: helium sequence. When all of the _____ hydrogen in the central regions is converted to helium, the star will begin to “burn” carbon helium into ________. sun Stars heavier than about 5 times the mass of the ______ hydrogen can do this with no problem: they burn _______, helium carbon and then ________, and then _______, oxygen ________, silicon, and so on…until Iron.
energy Iron is the lightest element that doesn’t release _____ when you attempt to fuse it together. You actually end up with less energy than you started with! So instead of generating pressure to hold up the outer layers, the iron fusion actually takes it out of the core. Thus, there is nothing left to combat ________ from the outer gravity layers. The result: ______! collapse This implosion (______) supernova happens very, very quickly: about 15 seconds. During the collapse, the nuclei in the outer parts of the star are pushed together, so close that Iron elements heavier than _____ are formed.
Summary Which type of Star is our Sun? ans. Average size i. e. smaller star Which last longer, our sun or a massive star? ans. Our sun What will be the fate of our Sun? ans. It will become a white Dwarf and a Black Dwarf Where does a Supernova come from? ans. a Super-MASSIVE RED GIANT