White+Dwarfs+4A

__**WHITE** **DWARFS STARS**__ White Dwarfs are what stars like our Sun become after they have lost all of their nuclear fuel. The only part of the star that remains is the hot core. Many of the white dwarfs around have been noticed as soft X-rays. The size of a white dwarf is half the massive size of the Sun but slightly bigger than the earth. Which makes white dwarfs one of the densest forms of matter. The added gas causes the dwarf to ignite explosively. When the heats expand on the outer layer of the how dwarf it produces a nova. __**WHATS INSIDE A WHITE DWARF?**__ The density of an earth-sized white dwarf is 1 x 109 Kg/m3. Which means it is 200,000 times as dense as earth. The surface gravity is 100,000 times of the earth. There is a limit on the amount of mass that a white dwarf can have. Which is 1.4 times the mass of our Sun. Some people call it "Chandrasekhar limit"

__**THE TEMPERATURE OF A WHITE DWARF**__ When the star is in the begin stage it is hotter than 100,000 K (which is about 180,000 F). When it cools down, after billions of years it's temperature is 6,000 K, it can become cooler than the Sun. A white dwarf has no actual temperature. The first few that were discovered were actually white with temperatures near 10,000K. Which are the easiest to discover. The typical temperature of a white dwarf is around 10,000K. It takes tens to hundreds of billions of years for it to become a black dwarf.

__**DIFFERENT TYPES OF DWARF**__ There are several different types of dwarfs. The most rare "white dwarf" is the blue with a temperature of 50,000K. It is the most rare because they cool quickly. They say that red and yellow have a temperature cooler than 6,000K. They are really hard to discover. When a white dwarf cools down and does show light it is called a black dwarf.

__**HOW ARE WHITE DWARFS ARE FORMED**__ White dwarfs are formed when a star has burned all of its original hydrogen and helium fuel to which become elements such as carbon, nitrogen and oxygen.

__**DISCOVERY**__ The first white dwarf was discovered by Adriaan Van Maanen who also discovered Van Maanen's Star, an isolated white dwarf. The unusual faintness of white dwarfs was first recognized in 1910 by Henry Norris Russell, Edward Charles Pickering and Williamina Fleming. The name white dwarf came from Willem Luyten.

__**LUMINOSITY OF A WHITE DWARF**__ They have a really faint luminosity that comes from the emission of stored heat. Of all the the stars in the solar neighborhood they comprise roughly 6% or all the stars. Their fate luminosity or glow comes from the emission or stored heat.