December 16, 2011

Objective: Construct a model of the life of a star

Agenda Notes Life of a Star Project Contact

Life Cycle of a Star

1st Stage of LifeBall of gas and dust that is pulled together by gravity

Nuclear fusion starts as gas cloud becomes denser and hotter

Nuclear Fusion hydrogen atoms fuse into heliumCreates the intense energy found in stars

Four types of stars make up the life of a starMain SequenceGiants Super GiantsWhite Dwarfs

Main Sequence (the Sun)2nd stageLongest stageHydrogen changes into helium which creates enormous amounts of energy

The size of the star does not change much

Giants and Supergiants3rd stageMain Sequence star becomes a red giant

Red giant star that expands and cools once is loses all its hydrogenCenter shrinks and atmosphere grows large and cools

White Dwarf small hot star that is the leftover center of an older starFinal stageCan shine for billions of years before they extinguish

Observe life of a star (link)

Age of starsAverage stars become red giants then white dwarfs

More massive stars explode into a variety of objects

Supernova gigantic explosion in which a massive star collapses Occurs after a massive star uses up its fuel source

Neutron Star a star that has collapsed to a point at which all particles are neutronsA neutron star that spins and sends out beams of radiation is called a pulsar

Black Hole an object that is so massive that light cannot escape its gravityRemnants of a supernova

Astronomers can detect black holes by using X-ray telescopes

Hertzprung-Russell DiagramShows the relationship between a star’s surface temperature and absolute magnitude

Used to study the lives of stars

Most stars lie along the main sequence portion of the diagram

Question 1

What kind of a star is the sun?

Answer

Main Sequence

Question 2

What is the H-R diagram?

Answer

A graph that shows the relationship between a star’s temperature and absolute magnitude

Question 3

What are the four main types of stars?

Answer

Main-SequenceGiants and Supergiants

White Dwarfs