The Dramatic Birth, Life, and Death of a Star STAR LIFE CYCLE The Dramatic Birth, Life, and Death of a Star

Nebula A nebula is a cloud of dust and gas, composed primarily of hydrogen (97%) and helium (3%). Within a nebula, there are varying regions when gravity causes this dust and gas

Proto Star Within a nebula, there are varying regions when gravity causes this dust and gas to “clump” together. As these “clumps” gather more atoms (mass), their gravitational attraction to other atoms increases, pulling more atoms into the “clump.”

The Main Sequence We now have reached STAR status. To be a star it much reach 6 million degrees C, and be able to do nuclear fusion. Stars spend most of their life as a main sequence star.

Nuclear fusion The reaction which occurs in stars. Through the combining of atoms of elements, such as hydrogen, a heavier element is created along with the release of a large amount of energy.

Main Sequence Star Continued The more massive stars the heavier the star the heavier the elements. Which is where most of the heavy elements in the universe are made. Throughout this whole process is that battle between gravity and gas pressure, known as equilibrium. It’s crucial to keep this battle in your mind when trying to understand how stars live and die.

Heavy element During the process of fusion in stars, atoms of hydrogen combine with other hydrogen atoms or different elements to form heavier elements.

Red Giant Star A Red Giant Star is a main sequence star that is not longer in equilibrium. There is a greater outward force than an inward force. Red Giants can increase a hundred times its size.

Question? Choose from the following hypotheses regarding length of star life: A. The bigger a star is, the longer it will live. B. The smaller a star is, the longer it will live. Now, for whichever hypothesis you chose, Write a 1-3 sentence explanation for why you think this is so.

Nova/ Super Nova Once the star becomes unstable the star will eventually explode which is called a Nova or Super Nova depending how massive the star is. The Bigger the Star the Bigger the Explosion!! The Bigger the Star the Shorter it will live.

What happens to the exploded star? After the Nova or Super Nova the gases and heavy elements produced through nuclear fusion are sent into space and become a new nebula were new stars and planet can form. There is also a left over core, and depending on the mass of the star depends on the name of size of the object produced.

The left over centers after the Nova or Super Nova Low Mass Stars ( Like our Sun): Become White Dwarfs then Black Dwarfs. Massive Stars: Become Neutron Stars Super Massive Stars: Become A Black Hole.

From Birth to Death…

The Star Life Cycle Compared to Human Life Cycle.