BLACK HOLE

Black holes are formed by dying stars.

          Black hole is like a black body, which absorbs all the radiations, but emits none.

          Light cannot pass through it .

          It has very strong gravity and all the matter is squeezed into a tiny space.

          It is called "black" ,because it absorbs all the light that hits the horizon, reflects nothing, just like a perfect black body in thermodynamics.

          Black hole is bigger in size.

          The smallest black hole can be in the size of an atom, but it contains mass of a mountain!!!.

          The mass of the largest black hole is more than 1 million suns together!!!.

          Every galaxy contains a black hole.

          "SAGITTARIUS A" is a black hole present in the centre of our galaxy(Milky way).

SAGITTARIUS A

**What happens we fall into a black hole ?

          As we go towards the centre the tidal force becomes so intense that it rips us apart.

**When no radiation is emitted, how a black hole can be found ?

          Scientists have found a way out of this dilemma.

          Black holes exert enormous gravity on nearby objects.

          Although scientists cannot see a black hole,but they can able to see its effects on the surrounding matter.

          Binary star systems are the best for finding black holes.

          Astronomers have detected many binary star systems.

          A binary star is a star system consisting of two stars orbiting around their common center of mass.

          Sometimes astronomers can see only one star, orbiting around an unseen companion.

          This star is too dim to see from the Earth.

          It could also be a black hole.