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If the Sun is a medium sized star, then what is the size and name of the largest size star and the smallest?

One of the largest (in physical size) stars is the red supergiant Betelgeuse in the constellation Orion. It has a diameter 500 to perhaps 750 times that of the Sun. One of the most massive stars is the variable star called Eta Carinae, with a mass of about 200 solar masses. The Guiness Book of World Records lists a white dwarf named L362-81 as the smallest star in size; its diameter is estimated to be only about 3500 miles, or about the same size as the planet Mercury. The star with the smallest mass (again, according to Guiness) is designated RG 0058.8-2807; its mass is only 0.014 solar mass (it is also the faintest known star).

RC Winther

The Sun is an "average" star and is 332,946.0 times as massive as the Earth. If you really mean "size", then the radius of the Sun is a little more than 100 times the radius of the Earth (695,990 km compared to 6378 km).


This is actually a hard question. It is difficult to determine the size of a star. If you mean the star with the biggest radius then it could be a star like Beutelguese in Orion which is a red giant that is nearing the end of its life. If you meant the amount of mass that the star has, it could be a black hole that is very massive, but not big in size. To determine the radius of a star we need to measure the brightness, the distance to the star, and the color. It is hard to know all of these. The color of the star is a measure of its part in the life cycle of stars.

Samuel P Bowen

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