Life Cycle of a StarLife Cycle of a StarA journey through it’s birth ‘til it’s death.A journey through it’s birth ‘til it’s death.

By Anna, Damon, Shannon, Jon, and PatriciaBy Anna, Damon, Shannon, Jon, and Patricia

ObjectivesObjectives How stars are formedHow stars are formed

What they are made What they are made up ofup of

What happens in the What happens in the middle of lifemiddle of life

Death of stars of Death of stars of different sizes different sizes

Birth of a StarBirth of a Star

Enormous clouds of Enormous clouds of gas and dustgas and dust

Gravity tries to pull Gravity tries to pull the materials togetherthe materials together

A giant ball formsA giant ball forms

Center of ball reaches Center of ball reaches 15 million degrees15 million degrees

Nuclear fusionNuclear fusionWhat is it?What is it?

Enormous pressure at center of ballEnormous pressure at center of ball

A plasma is createdA plasma is created

Nuclei crash together, then fuseNuclei crash together, then fuse

Midlife of a StarMidlife of a Star

Goal is to reach Goal is to reach equilibriumequilibrium

Main Sequence:Main Sequence:

1. Basic Reactions1. Basic Reactions

2. Hydrostatic equilibrium2. Hydrostatic equilibrium

3. Transport of energy3. Transport of energy

Hertzsprung-Russell (HR) DiagramHertzsprung-Russell (HR) Diagram

Death of a Star Death of a Star (depending on the mass of the star(depending on the mass of the star))

Sun-like stars Sun-like stars (mass under 1.5 times the mass of (mass under 1.5 times the mass of the Sun)the Sun)

Huge Stars Huge Stars (mass between 1.5 and 3 times the mass (mass between 1.5 and 3 times the mass of the sun)of the sun)

Giant Stars Giant Stars (mass over 3 times the mass of the Sun)(mass over 3 times the mass of the Sun)

Sun like stars Sun like stars (mass under 1.5 times the mass of the sun.)(mass under 1.5 times the mass of the sun.)

Become Red GiantsBecome Red GiantsAfter exhausting their After exhausting their hydrogen they burn hydrogen they burn HeliumHelium

Outer Layers Ejected to Outer Layers Ejected to Planetary NebulaPlanetary Nebula

Leaving a dense white Leaving a dense white dwarfdwarf

White Dwarf 1.4 White Dwarf 1.4

No fuel left to burnNo fuel left to burn

Radiates remaining HeatRadiates remaining Heat

Eventually becomes a Eventually becomes a

Black Dwarf if nothing Black Dwarf if nothing else effects starelse effects star

Red Super GiantRed Super Giant Rare due to short life spanRare due to short life span

2000 known in galaxy2000 known in galaxy

Made up of Helium, Hydrogen, Made up of Helium, Hydrogen, and carbonand carbon

8-10 times more massive then 8-10 times more massive then sunsun

Extremely bright for hundred Extremely bright for hundred thousand to a million yearsthousand to a million years

Implodes on itself ending in a Implodes on itself ending in a type II supernovatype II supernova

SupernovaSupernova Explosion of a star in spaceExplosion of a star in space

Occurs when nuclear fuel is exhaustedOccurs when nuclear fuel is exhausted

No longer supported by release of nuclear energyNo longer supported by release of nuclear energy

A rare event in our galaxy (last being seen in 1604)A rare event in our galaxy (last being seen in 1604)

Remnants can be seen for several weeksRemnants can be seen for several weeks

Supernova end phase is a neutron starSupernova end phase is a neutron star

Neutron StarNeutron Star Final stage in death of a starFinal stage in death of a star

May appear in supernova remnants, as isolated objects May appear in supernova remnants, as isolated objects or in binary systemsor in binary systems

About 20km and 1.4 times more massive then our sunAbout 20km and 1.4 times more massive then our sun

Posses gravitational field about 2 x 10^11 that of earthPosses gravitational field about 2 x 10^11 that of earth

Escape velocity is about half the speed of lightEscape velocity is about half the speed of light

Are electrically neutralAre electrically neutral

Death of Huge stars Death of Huge stars (mass between 1.5 to 3 times that of our sun)(mass between 1.5 to 3 times that of our sun)

Giant Stars Giant Stars (mass over 3 times the mass of the sun.)(mass over 3 times the mass of the sun.)

Red Super GiantsRed Super Giants

SupernovaSupernova

Black holesBlack holes

SummerySummery

Stars are made up of interstellar gasses, dust Stars are made up of interstellar gasses, dust and gravityand gravity

The goal of a star is to reach an equilibriumThe goal of a star is to reach an equilibrium

What a star turns into when it dies depends on What a star turns into when it dies depends on the size of the star whether it is smaller then our the size of the star whether it is smaller then our sun, the same size or larger then our sun sun, the same size or larger then our sun