Types of Stars Stars are Huge hot balls

Types of Stars

Stars are… • Huge, hot balls of gas that are trillions of kilometers away from Earth • Astronomers study starlight to learn more about the stars

Stars generate heat. • Think about the light generated by a candle. • Based on what you know about flames, which star would be hotter- orange or blue?

Stars have layers • Inner layers are very dense and hot • Outer layers are cooler gases • Elements in the stars atmosphere absorb some of the light that radiates from a star • Different elements absorb different wavelengths of light, so…. • Scientists can tell what elements a star is made of when they observe the light of the star.

Differences in Brightness • Originally, scientists classified stars by brightness – First magnitude (brightest) to sixth magnitude (dimmest) – As technology improved, scientists added to their classification system, all the way up to the 29 th magnitude (extremely dim star)

Life Cycle of a Star • First: • Stars are born in nebulae. Huge clouds of dust and gas collapse under gravitational forces, forming protostars. These young stars undergo further collapse, forming main sequence stars.

Life Cycle of a Star: • Next: • Stars expand as they grow old. As the core runs out of hydrogen and then helium, the core contracts and the outer layers expand, cool, and become less bright.

Life Cycle of A Star • This is a red giant or a red super giant (depending on the initial mass of the star). It will eventually collapse and explode. Based on the original mass of the star; it will become either a white dwarf then a black dwarf, OR neutron star, or black hole.

Life Cycle of a Star

• Follow these links to help you study: • http: //www. enchantedlearning. com/subjects/ astronomy/stars/lifecycle/ • http: //www. kidsastronomy. com/stars. htm