~ The Life and Death of Stars ~

Image credit: seasky.org

Life Cycle of a Star Interactive / Five Stages of a Supernova Explosion

Click here: Build Your Own Star Simulator / Supernova Creator Weavesilk

History Channel The Universe Series Part One / Full Documentary: Life and Death of Stars

Life Cycle of a Star Photo Gallery / News Article

Gas and Dust in a Stellar Nebula Above / Glowing Protostar Below

Star Formation / Stellar Nebula (Nursery) / Protostar Image Gallery

Main Sequence Stars: Blue Supergiant (Rigel), Medium Yellow Star (The Sun), Red Dwarf (Proxima Centauri)



Click here: The Life Cycle of a Star Like our Sun

Note: Our Sun is in the middle of it's Main Sequence Phase.

During this active phase, stars undergo nuclear fusion,

and release vast amounts of light and heat energy.

The Seven Stages of our Sun...


1) From a Stellar Nebula (recycled dust & gas cloud)...

2) to a Protostar (glowing, newborn star)...

3) to a Main Sequence star (active, shining star)...


4) to a Red Giant (cool, dying, swollen star)...

5) to a Planetary Nebula (colorful, emmision gas cloud)...

6) to a White Dwarf (hot, tiny, collapsed star)...

7) and finally to a Black Dwarf (cold, dead star remains).


FYI: 95% of all stars will end up as white, then black dwarfs.

Only 5% of stars are massive enough to explode as a supernova!


Star Birth / Star Death Movie Clips / Nova: Death Star

Death Star Pumpkin




~ The Hertzsprung-Russell Diagram ~

Surface Temperature vs. Luminosity (Absolute Brightness)

Learn about the H-R Diagram / Interactive Hertzsprung-Russell

Hertzsprung-Russell Video / Seventeen H-R Questions

Ejnar (ee-nar) Hertzsprung of Denmark and Henry Norris Russell of the USA

Note: Zero Kelvin is "Absolute Zero," or the temperature at which all matter stops moving.

Note: Zero Kelvin is equal to minus -272 degrees Celsius, and minus -459 degrees Fahrenheit.

Above: Star Color Examples in the Spring / Summer

Below: Star Color Examples in the Fall / Winter





~ Nuclear Fusion vs. Nuclear Fission ~


two (2) small atoms (Hydrogen & Hydrogen) smash, and FUSE together into one (1) larger atom (Helium)

( with a release of energy in the form of heat )


one (1) large radioactive atom (Uranium) SPLITS apart into two (2) smaller radioactive atoms (Barium & Krypton)

( with a release of energy in the form of heat )

Click here: Thermo-Nuclear Fusion in Stars

Shown Above: Tokamak Nuclear Fusion Reactor at MIT, Cambridge, MA

Main Sequence stars are made mostly of Hydrogen atoms in the form of a Plasma.

Click here: Plasma: The Fourth State of Matter




~ Giant Stars ~

Large-Sized Main Sequence Stars: (Blue Giants and Blue Supergiants)

Dying, Swollen Post-Main Sequence Stars: (Red Giants and Red Supergiants)

Click here: Learn about Red Giant Stars

Above: The Sun as a Main Sequence star

...compared to the size of the Sun as a Red Giant (amazing!)


Below: Red Supergiant star Betelgeuse

...compared to the size of our Solar System (amazing!)

Click here: Red Supergiant

During the stages of Nuclear Fusion Cycles in Red Giant Stars,

elements up to and including Iron (Latin: Ferrum) are created.

Elements Forged from Supernova Explosions - Elements in a Jar





~ Dwarf Stars ~

Click here: White Dwarf (dim, dying medium-sized star)

Click here: Planetary Emission Nebula (White Dwarf in center)

White Dwarfs eventually turn into Black Dwarfs...

Click here: Black Dwarf (dead star)

Click here: Red Dwarf (main sequence star < 40% mass of sun)

FYI: It is estimated that about 75% of all stars in our galaxy are small Red Dwarf stars.

Click here: Brown Dwarf (failed star) / Jupiter is a Brown Dwarf

( Dopey, Sneezy, Bashful, Sleepy, Happy, Grumpy, Doc )

Click here: Snow White and the Seven Dwarfs




Supernova Explosions!

Click here: Supernovae / Chandra Images / Supernova Remnant / Supernova Movie

Above: M95 Galaxy showing a (blue-hot) Supernova Explosion at Lower Right

Galileo Galilei
Johannes Kepler

The Italian scientist, Galileo Galilei,

witnessed the "Johannes Kepler" supernova explosion in the year 1604.

Click here: False Color Images

Above: Supernova Remnant Cassiopeia A in "false color"

Click here: Cassiopeia A - as seen by Hubble in Visible LIght

Click here: Birth of the Elements / Atoms & Elements

Note: All elements heavier than Iron (Fe) are created during Supernova explosions.




~ Neutron Stars and Magnetars and Pulsars ~

Click here: Neutron Stars


They are very, very, very DENSE objects.

One TEASPOON of a neutron star weighs as much as the EMPIRE STATE BUILDING!

MAGNETARS are neutron stars with a super strong magnetic field.

Magnetars release X-rays and Gamma Rays.

Click here: Pulsars

PULSARS are FAST-SPINNING neutron stars.

( They spin up to 600 REVOLUTIONS per SECOND! )

PULSARS release pulsing RADIO WAVES at their POLES, like a LIGHTHOUSE beacon.

Click here: Jocelyn Bell Burnell (discoverer of pulsars)

Click here: Info about Neutron Stars and Pulsars








~ Planetary Emission Nebula ~

(gases shed from a dying red giant star)

The following credited to: Planetary Nebula Website

95% of all stars that we see in our own galaxy, the Milky Way, will
ultimately become "planetary nebulae." This includes the Sun.

Planetary nebulae are formed when a red giant star ejects its outer layers as clouds of
luminescent gas, revealing the dense, hot, and tiny white dwarf star at its core.

The other 5% of stars -- that is, those born with masses more than eight
times (8x) larger than our Sun -- end their lives as explosive supernovae.

FYI: The name "planetary nebula" is a misnomer (not a good name choice)...

The name "planetary nebula" arose
long ago when Sir William Herschel looked through his small,
poor-quality telescope and saw these objects as compact, round, green-colored
objects that reminded him of the view of his newly discovered planet, Uranus.

Planetary nebulae are not made of planets, and no planets are visible within them.

Rather, they are the gaseous and dusty material expelled by a small to medium-sized dying star.

A far better name for these objects would be "emission nebulae" because they emit gases in a small burst, sort of like a "burp" of gases suddenly thrown outward into space.

~ Planetary Emission Nebula Photo Gallery ~

Above: The Eagle Nebula

Click here: Nebula Images

Above: Horsehead Nebula

Above: Rotten Egg Nebula

Above and Below: Cat's Eye Nebula




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