By: Christina Stevens

A nebula is: cloudiness in the urine.

 This is any star lying on a diagonal band that extends from hot stars of high luminosity to cool stars of low luminosity; any stars in the Hertzsprung-Russell diagram from the upper left to the lower right of the diagram.

 Red Giant is a star in an intermediate stage of evolution, characterized by a large volume, low surface temperature, and reddish hue.

 Planetary Nebula is an expanding shell of thin ionized gas that is ejected from and surrounds a hot, dying star of about the same mass as the sun; the gas absorbs ultraviolet radiation from the central star and reemits it as visible light by the process of fluorescence.

 Only the hot core of the star remains from the planetary nebula. This core becomes a very hot young white dwarf, which cools down over the course of about billion years. Then when the billion years are over, it turns into a black dwarf. This is when it has cooled down enough that it no longer emits light.

 Instead of fusing the hydrogen much slower that the small and medium stars, it begins to fuse even faster for the high mass stars. This means that they live less longer than the smaller ones because it doesn’t fuse as slow in order to make more time to live. The massive sequence stars eventually turns into a Red Supergiant.

 When the fusion entirely stops, the star collapses and creates a huge explosion. When viewed from the earth, a person can see the explosion as a huge ray of light. The burst of radiation, or light, can shine out an entire galaxy. The supernovas are known as the most powerful explosion on the whole universe.  Smaller supernovas leave the super giant star’s core behind in the form of a neutron star. A neutron star spins rapidly, at about 600 times per second, and is exceptionally dense, packing about 1.4 times the mass of the sun into an area not much bigger than the city of Chicago in the United States. As a neutron star spins, it creates radio waves which have been detected on Earth. These rapidly spinning stars are often called pulsars.

 This is a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.