https://padlet.com/446116/pggiaqixsbtt Allie Hannum en-us 2019-01-10 19:48:10 UTC 2026-01-20 18:27:22 UTC hello@padlet.com 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319447583 A stellar nebula is a large cloud of gas and dust that spreads out in a very large volume. Gravity pulls some of the gas and dust in a nebula together, forming a very hot ball of mass. This stage lasts until the cloud becomes dense enough to form a protostar. The protostar is not yet a star, just a growing mass that, over time, will become a star, just like a fetus is not yet a human, but over time it will grow into one.]]> 2019-01-10 19:52:06 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319447583 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319450451 A protostar is formed when the dense region in the nebula shrinks and warms up (the contracting cloud of a nebula). Due to the contracting gas and dust from the nebula becoming so dense and hot, nuclear fusion begins in this stage, but there is not yet a stable balance with it and gravity. This stage lasts about 1 million years. This is like when the star is officially "born" but it can't yet do normal star things like nuclear fusion, just like a baby is born but doesn't know how to do normal human things like talk, walk, etc.]]> 2019-01-10 19:57:08 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319450451 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319846412 A main sequence star is a star that is fusing hydrogen in its core (nuclear fusion) and has achieved a stable balance of outward pressure from the core nuclear fusion and gravitational forces pushing inward. This is the stage our Sun is currently in, as well as all stars we can see from Earth. This stage lasts about 5 billion years.  The star is capable of doing nuclear fusion, but still young, just like a child is capable of doing things but still young.  ]]> 2019-01-11 19:42:26 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319846412 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319847086 A red giant is a star with less mass, expanding and glowing red as it cools. It occurs when the star begins to run out of hydrogen fuel. As the amount of hydrogen decreases, the amount of nuclear fusion decreases, causing the star to cool. The outer layers expand as fuel is used. This stage lasts about 10 billion years. The star is still growing and still capable of doing nuclear of nuclear fusion and is expanding while still being relatively young just like a teen is capable of doing many things while still growing and being young.]]> 2019-01-11 19:44:08 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319847086 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319848231 A white dwarf is the exposed hot core of the star when it runs out of nuclear fuel. The blue-white hot core of the star that is left behind cools to become a white dwarf. It is very dense and its mass is the same as the Sun's, while its volume is the same as the Earth's. This stage lasts about 11 billion years.  The star is getting older and slowing down just like an adult is getting older and slowing down. ]]> 2019-01-11 19:46:32 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319848231 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319849651 A planetary nebula is formed when the outer layers of gas pull off of the star. As these layers drift into space, a cloud of gas is formed, creating it. These clouds are often in the shape of a ring or bubble. This stage lasts about 10 thousand years. A planetary nebula is breaking away from the star just like young adults are breaking away from their parents.  ]]> 2019-01-11 19:50:06 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319849651 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319850272 A white dwarf cooling is the stage where the white dwarf becomes even cooler as it radiates its energy. It's color changes from whitish blue to reddish. Over a very long time, it will cool and its material will crystalize. This stage lasts until the star has no more fuel and "dies". The white dwarf cooling star is starting to shrink a little bit and almost run completely out of fuel just like an elder will shrink and start to get very tired. ]]> 2019-01-11 19:51:36 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319850272 446116 https://padlet.com/446116/pggiaqixsbtt/wish/319850663 A black dwarf is the stage when the star has used up all its fuel and has completely crystalized. It no longer is able to emit light or heat. Since this stage takes longer than 14 billion years to reach, it is thought that no black dwarfs exist because the universe itself is only about 13.8 billion years old. The oldest white dwarves still radiate heat and have not yet burned out. A black dwarf has completely run out of fuel and no longer does nuclear fusion at all, just like when somebody dies they stop breathing, their heart stops beating and there is no more life left in them]]> 2019-01-11 19:52:34 UTC https://padlet.com/446116/pggiaqixsbtt/wish/319850663 446116 https://padlet.com/446116/pggiaqixsbtt/wish/320612374 A star is a really hot ball of gas/plasma with hydrogen fusing into helium in its core. A yellow dwarf is made up of six layers, three interior and three exterior. The interior layers are the core where nuclear fusion occurs, the radiation zone where energy travels through, and the convection zone where energy moves by convection. The exterior layers, which are part of the atmosphere, are the photosphere which is very thin and emits most of the light (the one we see on earth), the chromosphere which is the middle layer in the atmosphere (seen on earth only during a solar eclipse), and the corona which is the outermost, layer the "crown" of the star (also seen on earth only during a solar eclipse). ]]> 2019-01-15 04:08:25 UTC https://padlet.com/446116/pggiaqixsbtt/wish/320612374