UNIVERSE
THE SUN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It has a similar mass, but is much more dense
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it has a larger mass, but is less dense
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it has more mass, and is more dense
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it has less mass, and is less dense
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Detailed explanation-1: -A typical white dwarf is half as massive as the Sun, yet only slightly bigger than Earth. An Earth-sized white dwarf has a density of 1 x 109 kg/m3. Earth itself has an average density of only 5.4 x 103 kg/m3. That means a white dwarf is 200, 000 times as dense.
Detailed explanation-2: -Their small surface area means they radiate their heat away very slowly. It will take a white dwarf billions of years to cool down to temperatures near 10, 000 K. For comparison, the Sun’s surface temperature is around 6, 000 K.
Detailed explanation-3: -White dwarfs are very small (R = 0.01 Rsun = 1 Rearth) compared to a main sequence star, even though they have masses which are comparable to that of a main sequence star. Thus, white dwarfs must be very dense compared to an everyday main sequence star.
Detailed explanation-4: -The surface temperature of a white dwarf is higher than the surface temperature of the Sun. The more mass a white dwarf has the larger it is. A chunk of material from the interior of a white dwarf would weigh about 100 times more than an Earth rock of the same size.
Detailed explanation-5: -So what will happen to the Sun? In some 6 billion years it will end up as a white dwarf-a small, dense remnant of a star that glows from leftover heat. The process will start about 5 billion years from now when the Sun begins to run out of fuel.