WHAT IS WHITE DWARF?
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We all know about stars I.e. sun and etc.But there are many types of stars different by their brightness of emitted light.In stellar structure we shall now illustrate about white dwarf.White dwarf stars occupy a key position in astrophysics.The conception of these type of stars come from statistical mechanics.A white dwarf Sirius B whose existence was proved by the quantum-statistical theory of electron gas by scientist Fermi and Dirac .If a plot is made between brightness and the wavelength of the emitted light,then most of the stars fall within a linear strip,which indicates that the brightness is proportional to the wavelength.These sequence is called 'main sequence'.And there are two other type of stars exist.They are known as "Red giants" and "White Dwarf".Red giants stars are huge and abnormally bright.The white dwarf stars are highly under luminous.The white dwarf Sirius has a mass almost equal to sun but it's luminosity is only 0.03 times of sun.Hydrogen is the main thing in stellar surrounding.70 percent of mass of ordinary stars are made by hydrogen.From "Bethe's calculation of rates of thermonuclear reaction ,it is shown that white dwarfs have exhausted their thermonuclear energy sources and among the terminal states of stellar revolution,
.White Dwarfs have stellar masses but much smaller diameters and hence is very dense.The gravitational red shift of light predicted by Einstein's general theory of relativity and measured in the white dwarf Sirius B confirmed the small size and high density for this star.Some if the properties are given below of Sirius B with sun.Yhe properties will assure you about it's size,mass, luminosity etc.
Fig-graph of star's brightness versus wavelength
Fig-comparison of sun and Sirius B
We all know about stars I.e. sun and etc.But there are many types of stars different by their brightness of emitted light.In stellar structure we shall now illustrate about white dwarf.White dwarf stars occupy a key position in astrophysics.The conception of these type of stars come from statistical mechanics.A white dwarf Sirius B whose existence was proved by the quantum-statistical theory of electron gas by scientist Fermi and Dirac .If a plot is made between brightness and the wavelength of the emitted light,then most of the stars fall within a linear strip,which indicates that the brightness is proportional to the wavelength.These sequence is called 'main sequence'.And there are two other type of stars exist.They are known as "Red giants" and "White Dwarf".Red giants stars are huge and abnormally bright.The white dwarf stars are highly under luminous.The white dwarf Sirius has a mass almost equal to sun but it's luminosity is only 0.03 times of sun.Hydrogen is the main thing in stellar surrounding.70 percent of mass of ordinary stars are made by hydrogen.From "Bethe's calculation of rates of thermonuclear reaction ,it is shown that white dwarfs have exhausted their thermonuclear energy sources and among the terminal states of stellar revolution,
.White Dwarfs have stellar masses but much smaller diameters and hence is very dense.The gravitational red shift of light predicted by Einstein's general theory of relativity and measured in the white dwarf Sirius B confirmed the small size and high density for this star.Some if the properties are given below of Sirius B with sun.Yhe properties will assure you about it's size,mass, luminosity etc.
©:Debanjan Jana
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