Notes using the foldable Life Cycle of a Star Notes using the foldable

How long a star lives depends on the mass Life Cycle of a Star The smaller the stars, the longer the life because they use up their fuel more slowly Nebula Protostar Main Sequence Stars Red Dwarf Yellow Star Blue Giant Red Super Giant Red Giant Supernova White Dwarf Black Dwarf Black Hole Neutron Star

Nebula All stars begin as parts of nebulas A large cloud of gas and dust large amount of gas in a small volume, very dense

Different Masses mean different types of stars Protostar The 1st stage of a star’s life A contracting cloud of gas and dust Pressure and heat start nuclear fusion Different Masses mean different types of stars

Mass of star How long a star lives depends on how much mass it has A small mass star uses less fuel so it lasts longer so . . . The smaller the mass the longer it lasts

Main Sequence Stars More than 90% of all stars are found in the main sequence. In the main sequence, surface temperature increases as brightness increases. Main sequence stars are stars that are fusing hydrogen atoms to form helium atoms in their cores. These stars can range from about a tenth of the mass of the sun to up to 200 times as massive.

Red Dwarf A small mass star Can last up to 200 billion years

Yellow Star A medium mass star Our sun is a yellow star Lives for 10 billion years

Blue Giant A large mass star 10-15 times larger than the sun VERY hot Short lives because they have used up a lot of fuel

Red Giant The star runs out of fuel outer parts expand, then the core shrinks It turns red as it is cooling This phase will last until the star exhausts its remaining fuel. The pressure of the nuclear reaction is not strong enough to equalize the force of gravity so the star will collapse.

Red Super Giant The star runs out of fuel The core shrinks and the outer parts expand It turns red as it is cooling This phase will last until the star exhausts its remaining fuel. The pressure of the nuclear reaction is not strong enough to equalize the force of gravity so the star will collapse.

White Dwarf No more fuel left Faint glow from left over energy Outer parts drift out into space Small blue white hot core is left About the size of Earth

Supernova As the core shrinks, pressure increases Results in an explosion

Black Dwarf When the white dwarf stops glowing it is dead\very dense

Black Hole Remains of explosion collapse into a black hole Most large mass stars turn into black holes

Neutron Star After explosion some material left behind Forms a neutron star Dense and small

Life Cycle of a High-Mass Star Life Cycle of a Low-Mass Star Life Cycle of a High-Mass Star

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