Life of a Star

SMALL STAR LIFE CYCLE

• Stage 1 - Born in region of high density Nebula
• Stage 2 - Begins to heat up and form Protostars
• Stage 3 - Nuclear reactions in which hydrogen fuses
• Stage 4 - Releases energy to form Main Sequence Star
• Stage 5 - Remains in Main Sequence for 10 billion years

Small Stars - The Life of a Star of about One Solar Mass

• Stage 6 - Helium core starts to contract, causing reactions
• Stage 7 - Expanding star is now called Red Giant
• Stage 8 - Helium core runs out... Planetary Nebula
• Stage 9 - Remaining core in final stages: White Dwarf
• Stage 10 - Stops shining: Black Dwarf

MASSIVE STARS - Life of a Star of 10 Solar Masses

• Stage 1 - Massive stars evolve similar to small stars until Main Sequence Stage
• Stage 2 - Becomes a Red Supergiant and starts off with helium core
• Stage 3 - In the next million years, series of nuclear reactions occur
• Stage 4 - Core collapses in less than a second: Supernova
• Stage 5 - What does the core contract into? Neutron Star, Black Hole

Fun Facts

• Small Stars have a mass of up to 1 1/2 times that of the Sun
• Massive Stars have a mass 3x that of the Sun
• Some are 50x that of the Sun
• All stars are born, mature, and eventually die
• As a star dies, it ejects matter out into space