The sun is the star around which the entire solar system revolves.It is about 149.6
million kilometres from our planet and its light takes about 8 minutes to reach the
earth.The Sun's mass is 333,400 times that of the Earth, while its diameter is 109
times that of our planet.
Its nucleus, a ball of fire with temperatures that reach 19 million degrees Celsius,
is a gigantic thermonuclear laboratory where 4 million tons of hydrogen per second
are transformed into energy that takes about 30 million years to reach the surface.
|The sun during an eclipse
It has been calculated that to exhaust the Sun's energy takes
5 billion years. Its visible surface, the photosphere, has a depth of 3,000 km and
its temperature reaches 5,600°C. Observed with the proper instruments, it appears
formed by a group of granules which seem to end in enormous fiery columns.
Some of these granules become dark, the famous " sun spots" at times visible
to the naked eye, and can reach dimensions of tens of thousands of kilometres. When
our star exhausts its stores of hydrogen inside its nucleus, it will begin to swell
and grow increasingly brighter, transforming into a gigantic red star.