stars

I. Interstellar Medium

II. Nebula

III. Protostar

IV. Main Sequence

V. Red Giant

VI. Supernova

V. White Dwarf

_____________ _____________ is the total mass of the gas and dust between the stars.

Interstellar Medium

_____________ a dense cloud of dust and gases.NEBULA

The nebula begins to contract due to __________ and the pressure and temperature increase and becomes a ________________.

GRAVITYPROTOSTAR

When the temperature gets hot enough, _______________ begins and a _______ ____________ star is born.

FUSIONMAIN SEQUENCE

A star loses ____________ during fusion as energy is released. This decreases the star’s gravity. A star will expand, becoming a _________, when the outward force of __________ is greater than the inward force of ___________.

massRED GIANT

fusiongravity

As the fuel runs out in a star, _________ slows down. When the ______________ force of fusion is less than the ____________ force of gravity, the star will shrink in size, becoming a _________ _________.

fusionoutward inward

WHITE DWARF

A SUPERNOVA is an EXPLOSION that marks the end of a very massive star’s life.

Small and medium stars become __________________ once they die.

Larger stars become novae and die as: ____________NEUTRON STAR

BLACK DWARVES

Hertzprung-Russell Diagram

BRIGHTNESS• Variables which affect a star’s

brightness:• Star size• Distance from Earth• Star temperature

• Apparent Brightness: The amount of light received on Earth from a star.

• Actual Brightness: How large and hot a star is in relation to other stars.

• A star’s temperature can be determined by its color.• All objects will glow a different color when heated differently• Colors hottest to coolest: Blue/white yellow orange red.

GALAXIES

• Galaxy: A large group of stars, gas, and dust held together by gravity.

• Milky Way: Our galaxy which contains about 200 billion stars and many nebulas

Spiral Galaxies

• Galaxies are grouped together in clusters.

• The cluster the Milky Way belongs to is called the Local Group.

• Three types of galaxies:

• Cluster of galaxies

Elliptical Galaxies

• Elliptical Galaxies: Most common type of galaxy; large three-dimensional football shaped galaxies.

-Contain mostly older and dimmer stars.

Spiral Galaxies

• Spiral Galaxies: Circular galaxies that have arms curve outward from a central hub.– Arms are made up

of stars and dust

• Two spiral galaxies!!

More Spiral Galaxies

• Barred spiral galaxies: Have two spiral arms extending out.

Irregular Galaxies

• Irregular Galaxies: Come in many different shapes and are smaller and less common than elliptical or spiral galaxies.