LIFE OF A STAR BY: STACIA DEUTSCH AND RHODY COHON.

INTRODUCTION. Constellations are grouplings of stars. Stars gather in groups called galaxies. Our solar system is compromised of everything that orbits the sun like planets.

BIRTH OF A STAR The unaided human eye can see only a few thousand stars at a time. The spectral class types for stars are labeled O,B,A,F,G,K, and M. To sort stars, scientists look at their temperatures. Our sun is a class G yellow star.

BIRTH OF A STAR All stars begin a Nebula. Nebulas contain mainly hydrogen gas and a small amount of helium gas. Dark nebula clouds are often large.

PROTOSTAR During this phase a new star is called a protostar. The energy creates large, powerful jets of gas called bi-polar outflow. Sometimes stars form in clusters.

MAIN SEQUENCE OF A STAR. A star’s mass determines whether it moves on to the next stage. A main sequence star develops a core temperature of millions of degrees. As long as the star stays in equilibrium, it will remain a main sequence star.

PARTS OF A STAR It takes about 170,000 years for them to make it out of the star. Sunspots are dark, cool areas on the photosphere. Solar flares are sudden, violent explosions on the sun.

RED GIANT STAGE Most red giants are red but others can be orange or yellow. Aledebaran, a red giant is one of the brightest stars in the night sky. Some red giants may regain stability for a while.

CONVECTIVE ZONE. This layer is less dense and cooler than the radioactive zone. It takes a single photon only about ten days to reach the next level. These convection currents make the surface of the next level.

CORONA. The temperature of the corona averages 3.5 degrees. ☀ This is the collection of gases around the sun. It is much hotter than the core.

NUCLEAR FUSIONS. Nuclear fusion creates very light, nonelectric charges called neutrinos. By studying these neutrinos, scientists learn about fusion inside the stars. A proto star cannot begin nuclear fusion without enough mass or heat.

DEATH OF A STAR Star enters it’s final life stages as it runs out of fuel. Without, fuel a star cannot perform the same amount of nuclear fusion as it once did. It cannot stay in equilibrium.

WHITE DWARFS A white dwarf temperature slowly cools down over the next billion years. It emits very little light. At first, white dwarfs are so hot that they still glow.

BLACK DWARFS There are no known black dwarfs in our universe. All that will remain is a black lump of carbon, known as a black dwarf. Scientists think it takes so long for a while dwarf to cool, that no black dwarfs have been created yet.

RED SUPER GIANTS.. Red super giants begin to die like red giants do. Their gravity causes the outer layers to collapse inward. Unlike red giants, stellars winds are common and strong on a red super giant.

SUPERNOVAS A supernova is caused in the star’s cove. The iron is too heavy for fusion to continue. The energy is released as extremely bright supernova

QUESTIONS How do galaxies hold so many stars? (Ch 1-1)

QUESTIONS How do stars seem to twinkle?(Ch 1-2)

QUESTIONS Why do stars come in clusters? (Ch 1-3)

QUESTIONS Why does stars form in hot temperatures? (Ch 1-4)

QUESTIONS How does gravity pull stars closer??(Ch 2-1)

QUESTIONS Why can’t astronomers be sure why disk disappear? (Ch 2-2)

QUESTIONS Why can’t you be sure when you see a brown dwarf? (Ch 2-3)

QUESTIONS Why are sunspots cool? (Ch 2-4)

QUESTIONS Why is the collection of corona gases surrounded around the sun? (Ch 3-1)

QUESTIONS Why do scientists have to use a special measurement for long distances? (Ch 3-2)

QUESTIONS How do stars get there color? ( Ch 3-3)

QUESTIONS Why aren’t all giants red? (Ch 3-4)