Stars

Stars Our Sun is one type of star Create their own light Nuclear fusion generates energy

Atoms slam into each other at high temperatures and velocities to form larger heavier atoms

Classified based on: size brightness temperature luminosity (brightness)

Our Sun● Our Sun is merely a spec in the Milky Way

● the Sun and Earth are located ½+ away from center in one of the spiral arms

● Sun orbits Milky Way at about 235 km/s around the center of the galaxy

You are here!

Stars

Typesprotostarmain sequencedwarfgiantsuper giantneutron

Colorsblueblue-whitewhiteyellowred-orangered

Magnitudes of Stars use telescopes to

observe and measure light from stars

magnitude = brightness of a star

absolute – a measure of the light given off by a star

apparent – a measure of the amount of light received on Earth from a star

Stars: HR DiagramHertzsprung-Russell diagram organizes stars

by temperature, brightness and groups by color and type

“X-axis” = star temperature (reversed)

“Y-axis” = absolute

magnitude (brightness)

Star Types are grouped together

Stars: Life Cycle—small star (Sun)

1. nebula = large area of gas & dust where stars are born (Protostar)

2. main sequence = stable, longest stage

3. red giant = star grows, but cools

4. white dwarf = star shrinks (moon size), but heats up; dying process

5. black dwarf = dead star

Stars: Life Cycle—massive star

1. nebula = large area of gas & dust where stars are born (Protostar)

2. main sequence = stable, longest stage

3. red supergiant = star grows, but cools

4. supernova = star blows off outer portion of gasses

5. neutron star = very small, massive, hot star

Stars: Life Cycle—VERY massive star

1. nebula = large area of gas & dust where stars are born (Protostar)

2. main sequence = stable, longest stage3. red supergiant = star grows, but cools4. supernova = star blows off outer portion

of gasses5. black hole = so small and dense, that

even light cannot escape its gravitational pull

Life Cycle of a Star

Let’s Check…

1. Stars are classified by 4 major things: What are they?

2. What graphic do we use to compare stars?

3. The 6 major colors of stars are _?_.

4. Will our Sun go supernova? Why or why not?