FC: My Baby Rigel
2: Fetus (The Nebula Stage) Rigel was formed in a cloud of gas (hydrogen) and dust in space. His temperature was mainly cool. His mass was only a tiny | 100,000 to a few million solar units. He was very large at this point in time. He will become a protostar when eventually the gas clumps compress and start spinning due to gravity. A similar example of my little baby star, Rigel, is Orion's Nebula. He was very colorful and he wasn't very dense at all. Nebula are the places where stars are born and where my little Rigel began to take shape and began his wonderful life as a star!
3: Newborn Star (Protostar) This is where my Rigel was first born. Being a protostar is the early stage in the process of star formation. He formed by the contraction out of the gas of a giant molecular cloud. For one solar-mass this stage lasts about 100,000 years. In all this stage lasts from 100,000 to 10 million years but it all depends on the mass of the star. His temperature increased from when he was a Nebula and was cool, to 200 to 300K. In this process the core collapsed, nuclear fusion reactions began, and my baby star, Polaris, was born.
4: The terrible Twos (T TAuri star) Rigel is now a young, toddler star. In this stage of his life he is one of the youngest visible spectral type stars. My little Rigel would also be considered a pre-main sequence star because his surface temperature is similar to the temperature of a main sequence star of the same mass. However, | Rigel is much more luminous than a main sequence star. During this stage of my baby's life his central temperature is to low for fusion to occur. Instead he is powered by | gravitational energy released as he contracts toward the main sequence. Rigel we last in this stage for 100 million years before he reaches the next stage of his life as a star.
5: pressure from the hot core is pushing against inward gravitational pressure from outer layers. This is a constant battle to stay alive. If Rigel gives in to the inward gravitational pressure he would collapse. | Rigel hits Puberty (Main sequence star) Rigel is now beginning the main sequence stage of his life, This is where he will spend most of his life. Now he can begin the process of fusion. This is where he will fuse hydrogen into helium in his core to create energy. He will no longer be powered by gravitational energy like he has been powered by for the past 100 million years. Right now Rigel is experiencing hydrostatic equilibrium where outward thermal | of fusion. This is where he will fuse hydrogen into helium. He will no longer be powered by gravitational
6: Aging Star (Red Supergiant) At this stage my grown up boy, Rigel, runs out of protons or otherwise known as the nuclei of hydrogen atoms. All that is left in his core is alphas which are also known as the nuclei of helium atoms. However, my big boy is not completely | out of hydrogen atoms but they are in the outer layers of the star where it isn't hot enough to fuse. This causes him to start to cool down and to also contract. Then as the outer layers fall inward under gravity, they heat up. Then, the shell the surrounds the inner core finally becomes hot enough to fuse protons into alphas. Rigel, now having a new energy source, is now hotter than he was during his regular life. The heat now causes the outer regions of the star to swell, transforming Rigel into a supergiant. He then starts fusing heavier and heavier elements. When the iron builds up in the core of the star, the process stops. At this point it takes more energy to fuse iron than it creates.
7: Old Man (Supernova) When his darling little fusion has stopped he collapses into himself under the weight of gravity. The outer layer is then exploded out resulting in a supernova. My aging boy then shines so brightly that he can be seen for months during the day! He causes a burst of radiation that often outshines an entire galaxy. In this short interval of Rigel's life, he can radiate as much energy as the sun is expected to over its whole life time. This gigantic explosion expels the star's material at a velocity of 30,000 km (10% of the speed of light) driving out a large shock wave which sweeps up an expanding shell of dust and gas which is called a supernova remnant.
8: Dead Rigel (Black Hole) A black hole is a region in space in which nothing can escape, including light. It is caused by a very compact mass that results in a deformation in space time. Rigel gets the name black from black hole because | it absorbs all the light that hits it and reflects nothing back. Black holes are the endpoints of stars that are at least 10 to 15 times the mass of the Sun. They are created after a star goes through a supernova explosion. When it has no outward force to oppose the gravitational forces the stellar remnant will collapse on itself. When the star ultimately collapses to a point of infinite density and zero volume, then it is finally a black hole.