Download Life Cycle of a Star

Cut and GLUE
Life Cycle of
a Star
Types of STARS
Life cycle of an
AVERAGE star:
Nebula: gas and
dust
(high mass stars are bigger)
• The center of the nebula
gets hotter as it shrinks,
b/c of friction.
• Nuclear fusion of H
begins at 14 million
degrees K.
Main Sequence Stage
• “Middle Age” This is
where stars spend
most of their lives.
• The larger the mass,
the SHORTER the life
span.
Low mass stars (Sun) then
become a RED GIANT
• The star expands up
to 100 times its
original size after its
hydrogen is depleted
• At this point the star
will collapse
Planetary nebula
At the end of the red
giant stage, the star
blows its outer layer
of ionized gases off
into space.
White Dwarf:
Eventually gravity
crushes the matter in
the star into a small
planet-sized core of
immense density that’s
very bright.
Black Dwarf: dead star
• Eventually a white
dwarf will cool down
and form a black
dwarf.
• A ball of gas which is
not capable of nuclear
fusion within its core.
The Fate of the
Sun/Earth
https://youtu.be/peNeE3qCMH8
Life cycle of a
MASSIVE star:
Nebula: gas and
dust
(high mass stars are bigger)
• The center of the nebula
gets hotter as it shrinks,
b/c of friction.
• Nuclear fusion of H
begins at 14 million
degrees K.
Main Sequence Stage
“Middle Age”
This is where
stars spend most
of their lives.
Are born on the main
sequence, but run out
of Hydrogen faster.
(MORE mass, MORE
hydrogen, MORE
energy.)
The violent death of a high
mass star, occurring when
nuclear fusion within the
star can no longer produce
the heat required for
equilibrium.
The star collapses and then
EXPLODES!!!!
If the collapsed core
of a supernova is 2X
the size of sun, it
shrinks to 20 km in
size with the density
of 1 tsp weighing 100
million metric tons!!!!
If the collapsed core is 3X or
more massive than the sun:
An incredibly dense object
whose gravity is so strong
that not even visible light
can escape from it forms.
Black holes seem to warp
space and time around
them.
Our Sun:
Is a low-mass star that will follow
the red giant, white dwarf, black
dwarf stages in approximately the
next 5 billion years….we will NOT
EXPLODE into a supernova!
Planet/Star Comparison
https://youtu.be/HEheh1BH34Q