What is a star?

A big ball of gas & nuclear fusion

• Nuclear fusion is the explosion of energy when atoms combine.

** Intense gravity fuses Hydrogen into Helium

Man made nuclear fusion

Star sizes

• The color of stars indicates the temperature of stars

- blue is hottest

- red is coolest

Binary star system is a star system with two stars

A scatter scatter graph that shows the relationshipbetween star’s absolute magnitudes and temperature of the stars. *** Known as a H-R Diagram

The Sun

The Sun• Is a middle size class G star.

Sun spots• Areas of the sun where the gas is cooler.

Coronal Mass Ejections• Large amounts of electrically charged gas are ejected suddenly from the Sun’s corona.

• Can cause disruption in satellite transmissions or even shut down all electro-magnetics.

Solar flares

•Explosion of gas from the Sun’s surface

Solar prominences•Loops of gas connecting sun spots.

Birth of stars

•The gas and dust are pressed together until nuclear fusion occurs.

•Stars are born when the dust and gas of a NEBULA are pulled together by gravity.

Proto star

• The earliest stage of a star.(Baby star)

Nebula

•Stellar cloud of gas and dust.

•The birthplace of stars

Birth of stars

Star death•A star dies when it runs out of fuel

How long a star lives depends on the amount of mass it has.

• Big stars burn fuel faster

• A light year is the distance light travels in one year.

is measured In light years.

Stars distance

How can we measure star distances?

Parallax

•The apparent movement of stars

•Based on the change in Earth’s position

• Uses the principle of triangulation.

Apparent magnitude• How bright a star appears to be

Absolute magnitude

• How bright a star actually is.

Fate of Stare

•Small and middle size stars expand out into red giants and then shrink into a White dwarf

•A white dwarf is a very small and cool, formed when middle size stars die

Giants and super giants can blow up into a supernova•An exploding star

The remains of a supernova can become either a neutron star or a black hole

Neutron star• Dense remains of a super nova that is smaller than a white dwarf

Black hole•A dense area of space where gravity is so strong that everything is sucked into it.

Our suns will expand out into a red giant and then collapse into a white dwarf.

Constellations

The arrangement of stars in patterns

Galaxies•A massive cluster of stars

Types of Galaxies

Shaped like a spinning pinwheelChart designation:"S" to stand for spiral galaxies

Spiral

Barred Spiral Galaxy

A spiral with a solid bar across the center.

Chart designation:"SB" to stand for barred spirals.

elliptical

Shaped like an oval disk

Chart designation:"E" to stand for elliptical galaxies.

Irregular

No definite shape    Galaxies that can't be classified as either spiral or elliptical are called irregular galaxies.

•Our galaxy is the Milky Way

•The Milky Way is a spiral galaxy

History of the universeThe universe is said to have begun with the Big bang

Big Bang Theory• All matter blow out from a beginning point

The universe is continuing to expand

It is thought that the universe will collapse into nothingness