The sun is a star of the Solar system around which all planets entering it rotate. At the same time in comparison with the planet Earth it is possible to call the sizes and mass of the Sun without exaggeration enormous.
Size of the Sun
The sun represents a star which temperature on a surface reaches several thousand degrees therefore its light, having even passed huge distance to Earth, remains too bright in order that it was possible to look at the Sun with a naked eye.
Therefore to the ordinary person to estimate the sizes and a form of the Sun rather difficult. At the same time, scientists-astronomers established that the Sun represents the sphere having almost regular shape. Therefore for assessment of the sizes of the Sun it is possible to use the standard indicators used for measurement of the sizes of a circle.
So, diameter of the Sun is 1.392 million kilometers. For comparison, diameter of Earth is only 12,742 kilometers: thus, on this indicator the size of the Sun exceeds the size of our planet by 109 times. At the same time the circle of the Sun on the equator reaches 4.37 million kilometers whereas for Earth it is an indicator is equal only 40,000 kilometers, in this measurement the sizes of the Sun appear more, than the sizes of our planet, in the same number of times. At the same time, thanks to huge temperature its size gradually decreases by the surfaces of the Sun which makes nearly 6 thousand degrees. The scientists researching solar activity claim that the Sun within each hour is reduced in the diameter at 1 meter. Thus, they assume, hundred years ago diameter of the Sun was about 870 kilometers more, than now.
Mass of the Sun
The mass of the Sun differs from the mass of the planet Earth even more considerably. So, according to the statements of astronomers, at present the mass of the Sun is about 1.9891*10^30 kilograms. At the same time the mass of Earth is only 5.9726*10^24 kilograms. Thus, the Sun is heavier than Earth almost in 333 thousand times. At the same time, thanks to high temperature on the surfaces of the Sun, the majority of the substances making it are in gaseous state, so, have rather low density. So, 73% of structure of this star fall on hydrogen, and the rest - on the helium borrowing in its structure about 1/4 and other gases. Therefore in spite of the fact that the volume of the Sun exceeds the corresponding indicator for Earth more than in 1.3 million times, density of this star nevertheless is lower, than at our planet. So, density of Earth is about 5.5 g/cm³ whereas density of the Sun - about 1.4 g/cm³: thus, these indicators differ approximately by 4 times.