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”!!!!