110 likes | 328 Views
LIFE CYCLE OF A STAR. Astronomy 7 th Grade Chapter 2.2. The Beginning and End of Stars. A star enters the first stage of its life cycle as a ball of gas and dust. As this ball of gas becomes denser, it gets hotter and changes to helium – __________________.
E N D
LIFE CYCLE OF A STAR Astronomy 7th Grade Chapter 2.2
The Beginning and End of Stars • A star enters the first stage of its life cycle as a ball of gas and dust. • As this ball of gas becomes denser, it gets hotter and changes to helium – __________________. • As stars age, they lose some of their material. • When a star dies, they could explode in the form of a ____________________.
DIFFERENT TYPES OF STARS • Stars can be classified by their: • Size • Mass • Brightness • Color • Temperature • Spectrum • Age
PROTOSTAR: A Star is Born • Born in a Nebula: an _____________and other _______________. • A Baby Star • ________ in Color • Forms over _______ of years
MAIN SEQUENCE • Second and ____________ stage of a star’s life cycle • Energy is generated in the core of the star. • Hydrogen atoms fuse into Helium atoms. • This process releases an ENORMOUS amount of Energy.
GIANTS and SUPERGIANTS • Third Stage of Life Cycle • RED GIANT: a star that _________ and ___________once it uses all of its hydrogen. • The loss of hydrogen causes the center of the star to _________________. • The atmosphere of the star grows very _______ and _______________ to form this RED GIANT! • Red Giants: 10x bigger than the Sun. • Super Giants: 100 x bigger than the Sun
WHITE DWARFS • FINAL stage of a star’s life cycle. • Has same mass as the sun or smaller • White Dwarf: small, hot star that is the leftover center of an older star • NO _______________ LEFT! • NO LONGER CAN GENERATE __________ by fusing hydrogen atoms into _____ atoms. • Can shine for _____________of years even after they die.
SUPERNOVAS • Supernova: A gigantic ____________in which a massive star collapses and throws its outer layers into space. • This explosion powerful that it could be brighter than an entire galaxy for days!
NEUTRON STARS • After a Supernova, the center of the collapsed star contracts to form a new star. • The mass of the new star is about 2x the mass of the Sun – WOW! • A star has collapsed under gravity to the point where all the star particles are NEUTRONS.
PULSARS • If a neutron star is ____________, it is called a PULSAR. • A PULSAR sends out a beam of __________. • The beam is detected on Earth by telescopes as rapid clicks, or pulses (hence – PULSAR).
BLACK HOLES • If the center of a collapsed star has a mass more than 3x the mass of the sun, the star may contract. • The 3x star contracts because of the strength of its gravity. • The force of the contraction CRUSHES the dense center of the star. • It leaves a BLACK HOLE. • BLACK HOLE: An object that is so massive that light cannot escape its gravity. WOOH!