THE BEGINNING OF A STAR'S LIFE...
STAR FORMATION NEBULA
A Nebula is the start of a star's life. It is a cloud of gas, dust, and other matter in space. Gravity brings the gas and dust in the cloud closer together. It also makes it warmer and shrinks it. While the cloud is getting tighter, it starts rotating fast in the form of a circle. Parts of the cloud starts to pile up to the center, and the center starts heating the cloud up using energy.
PROTOSTAR
A protostar is a fragment of a nebula that liquefies into a hot sphere. Gravity oppresses the nebula to heat it up and it eventually glows. Nuclear fusion will begin after the temperature and density accelerates. It is now leaving the protostar stage and forming into an actual star.
MAIN SEQUENCE STAR OR MASSIVE STAR
FROM A PROTOSTAR, IT EITHER TURNS INTO A MAIN SEQUENCE OR MASSIVE STAR
A main sequence star is the "adult" star. Our sun is a main sequence star. They fuse hydrogen atoms to form helium atoms inside their cores. This star can last five billion years or more because it makes four billion tons of hydrogen per second. If a main sequence star is blue or white, it is HOT. If it is red, it is COOL.
A protostar can also turn into a massive star. A massive star is eight times larger than a main sequence star like the sun. They fuse faster, are brighter, and collapse strikingly. It is rare for stars to become so massive.
RED GIANT OR RED SUPER GIANT
MAIN SEQUENCE STAR= RED GIANT; MASSIVE STAR= RED SUPER GIANT
When a main sequence star runs out of hydrogen atoms, it turns into a red giant. Gravity oppresses this star, making it smaller. Its flames have disappeared from its past stage. It is a dying star.
Red supergiant stars are the largest stars in the universe. They will go on as a red supergiant until their core reaches a high enough temperature to commence fusion helium into carbon and oxygen. They are not necessarily the largest stars in the universe by mass, only in volume and diameter.
PLANETARY NEBULA OR SUPERNOVA
RED GIANT= PLANETARY NEBULA; RED SUPERGIANT= SUPERNOVA
A planetary nebula forms when a star can't support itself anymore with fusion reactions. Due to its weakness with fusion reactions, a star's core will shrink quickly, causing gases to move outwards. The gases form a cloud, which heats up and eventually glows. That is how a planetary nebula is formed. They are made of fragments of a star that died.
A supernova is the explosion of a star, the biggest explosion that takes place in space. A supernova is caused by a sudden change in the center/core of a star. The center/core got too heavy due to a star running out of nuclear fuel, and their mass falls to the center/core.
BLACK HOLE OR NEUTRON STAR AND WHITE DWARF
SUPERNOVA=BLACK HOLE OR NEUTRON STAR
PLANETARY NEBULA= WHITE DWARF
PLANETARY NEBULA= WHITE DWARF
A black hole is a body in space with a consuming gravitational pull that nothing can ever escape from. No light or radiation can even escape! Once a star dies, all the mass is thrown in the center, causing an intense pull where both time and space stop.
A neutron star is a stellar object that is born from an explosive death of a star. The explosion causes the star's outer layer to blow off, leaving the core. Gravity pulls the core in so tightly that protons and electrons combine and make neutrons. It is now a neutron star.
AND
A white dwarf is basically a star composed of electron-degenerate matter. They are the last evolutionary state for stars who cannot be neutron stars. A white dwarf has no source of energy, so it slowly radiates away and cools down. Sooner or later, it will not produce any heat/light, and it will become a black dwarf
BLACK DWARF
A WHITE DWARF BECOMES A BLACK DWARF
A WHITE DWARF BECOMES A BLACK DWARF
A black dwarf is exactly the same as a white dwarf, but it does not emit any source of light/heat. It is called a black dwarf because it has no heat, not because it is actually the color black.