How much does the sun weigh?

Hint: We need to understand that the sun is a star like the many other in the milky way galaxy and in other galaxies. These are huge bodies which can produce light and heat by nuclear fusion of light nuclei like the hydrogen and other elements.

Complete answer:
Sun is the star which controls and coordinates the solar system which includes the eight planets, their natural satellites, asteroid belts, comets and other dwarf planets. All these celestial objects are subject to gravitational force by virtue of the huge mass of the sun. The gravitational force keeps these planets without leaving the solar system.
The revolution of the planets around the sun is due to this strong gravitational force which dominates all other forces in the universe. The possibility of the life on earth is solely due to this gravitational force which is given by the Newton’s gravitational force as –
\[{{F}_{G}}=\dfrac{GMm}{{{R}^{2}}}\]
Where, G is the gravitational constant, M is the mass of the sun, m is the mass of the celestial object and R is the distance from the sun.
We can understand that the sun should be very huge as compared to the mass of the celestial bodies in order to have a force strong enough to hold the planets under its control
The mass of the sun is therefore,
\[M=1.989\times {{10}^{30}}kg\]
This is the mass of the sun which can keep all its planets under its force of gravity and thus forming the solar system.
This is the required solution.

Note:
The sun is a moderate star in the milky way galaxy. There are stars which are many folds larger than the sun that the sun is considered as small stars as compared to them. The large stars form black holes when they die, but the sun will just be a supernova.