~ The Life Cycle of a Star ~
Picture from: seasky.org
~ THE LIFE CYCLE OF A STAR LIKE OUR SUN ~
Click here: The Life Cycle of a Star Like our Sun
Note: Our Sun is in the middle of it's active Main Sequence Phase.
During this phase, stars undergo nuclear fusion,
and release vast amounts of light and heat energy.
Click here: Main Sequence Stars
FYI: 95% of all stars will end up as white, then black dwarfs.
Only 5% of stars will explode as a supernova!
~ The Hertzsprung-Russell Diagram ~
Surface Temperature vs. Luminosity (Absolute Brightness)
Note: Zero degrees Kelvin is "Absolute Zero," or the temperature at which all matter stops moving.
Note: Zero degrees Kelvin is equavalent to -272 degrees Celsius.
Note: A star's "Luminosity-Brightness" and "Surface Temperature" are interrelated.
Above: Star Color Examples in the Spring / Summer
Below: Star Color Examples in the Fall / Winter
~ Nuclear Fusion vs. Nuclear Fission ~
NUCLEAR FUSION: (2) HYDROGEN ATOMS SMASH and FUSE into HELIUM with a RELEASE of ENERGY
NUCLEAR FISSION: (1) HEAVY ELEMENT SPLITS into (2) SMALLER ATOMS with a RELEASE of ENERGY
Click here: 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
~ Red Giants and Red Supergiants ~
Click here: Red Giant
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 (Fe) are created.
~ Dwarf Stars ~
Click here: Snow White and the Seven Dwarfs
Dopey, Sneezy, Bashful, Sleepy, Happy, Grumpy, Doc
Above: M95 Galaxy showing a (blue-hot) Supernova Explosion at Lower Right
The Italian scientist, Galileo Galilei,
Click here: False Color Images
Above: Supernova Remnant Cassiopeia A in "false color"
Note: All elements heavier than Iron (Fe) are created during Supernova explosions.
Neutron Stars and Pulsars
Click here: Neutron Stars
Click here: Pulsars (Spinning Neutron Stars)
Click here: Jocelyn Bell Burnell (discoverer of pulsars)
FYI: Neutron stars are very, very dense objects.
One teaspoon of a neutron star weighs as much as the Empire State Building!
Click here: Info about Neutron Stars and Pulsars
Click here: BLACK HOLES
The following credited to: Planetary Nebula Website
95% of all stars that we see in our own galaxy, the Milky Way, will
Much as a butterfly emerges when its chrysalis is ejected, planetary nebulae
The other 5% of stars -- that is, those born with masses more than eight
One final note: the name "planetary nebula" is a misnomer. The name arose
However, "planetary nebulae" are not made of planets, and no planets are
Rather, they are the gaseous and dusty material
A far better name for these
Think of ejection nebulae as a cloud of
THE REVOLUTION STARTED BY IMAGES FROM THE HUBBLE SPACE TELESCOPE
Above: Planetary Nebula and Companion Binary Star
Hubble Space Telescope images are generating some very creative ideas about Planetary Nebulae:
"One example is that a nearby companion star, or perhaps a large
~Planetary 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