Transcript THE BIRTH AND DEATH OF A LOW/MEDIUM MASS STAR

THE BIRTH AND DEATH OF A
LOW/MEDIUM MASS STAR
Stars begin as NEBULAS, a large cloud
of dust and gas
Protostar
Gravity pulls the
dust and gases
together.
As they pull
together, the
atoms “fuse”
together.
This nuclear fusion
creates light!
The “star” begins
to glow.
MAIN SEQUENCE
STAGE
• THE STAGE WHEN A STAR IS IN IT’S
“BEST” LIFE CYCLE
• OUR SUN IS A MAIN SEQUENCE STAR
• MAIN SEQUENCE STARS HAVE MOSTLY
HYDROGEN.
• THE HYDROGEN EXPLODES, GIVING OFF
LIGHT AND HEAT
• AS IT EXPLODES, THE HYDROGEN TURNS
TO HELIUM.
• HELIUM IS LIGHTER THAN HYDROGEN.
• OUR SUN IS 4.6 BILLION YEARS OLD.
• IT WILL REMAIN A MAIN SEQUENCE STAR
FOR ANOTHER 4.4 BILLION YEARS.
RED GIANT
• WHEN THE MAIN
SEQUENCE HAS MORE
HELIUM THAN
HYDROGEN, IT EXPANDS
INTO A GIANT. HELIUM IS
LIGHT AND FLOATS
OUTWARD.
• THE CORE SHRINKS.
• THE STAR TURNS TO A
‘COOL’ RED BECAUSE IT
NO LONGER HAS MUCH
HYDROGEN TO MAKE
EXPLOSIONS OF LIGHT
AND HEAT.
• IT BEGINS TO ‘DIE’!
PLANETARY
NEBULA
• THE OUTER PART,
WHICH IS MAINLY
HELIUM, BEGINS
TO DRIFT INTO
SPACE.
• IT NO LONGER
HAS THE ROUND
SHAPE.
• THE CORE
REMAINS.
WHITE
DWARF
• THE OUTER PART
FLOATS INTO SPACE,
WHERE IT IS PULLED
BY GRAVITY WITH
OTHER GASES TO
FORM ANOTHER
NEBULA.
• THE REMAINING
CARBON CORE
GLOWS FROM
LEFTOVER HEAT, BUT
DOES NOT FORM
NEW HEAT.
• THIS IS A WHITE
DWARF.
BLACK
DWARF
• AFTER BILLIONS OF
YEARS, THE WHITE
DWARF WILL STOP
GLOWING.
• ALL ENERGY IS
GONE.
• THIS IS A BLACK
DWARF.
• OUR UNIVERSE IS
TOO YOUNG TO
ACTUALLY HAVE A
BLACK DWARF YET!!
• THE PICTURE IS AN
ARTIST’S DRAWING.
THAT WAS “WAY OUT”!!!!