Twinkle Twinkle little star, how
I wonder what you are????
Ever
imagined what a Star is after high school?
Well it’s a fixed luminous point in the night
sky that shines brightly miles away. These huge giant spheres are made up of
very hot gases. These gases are mostly hydrogen and helium.
These lustrous elements shine by fusing hydrogen into helium. Miles
away from the earth, Stars appear to be so small. But actually they are much
bigger than the Sun itself. Many stars also come in pairs called binary stars.
The life cycle of stars can be classified into
4 parts:
·
Birth
·
Main sequence
·
Red Giant
·
Collapse phase
The formation of a star begins with
gravitational instability within a molecular cloud. Gravity forces the dust to
come together. When more and more dust bunches up, gravity gets stronger.Thus
increasing the temperature becoming and a protostar. Once the center has
sufficient amount of heat, nuclear fusion will begin and a young star is born.The
star in its youth (less than 10 million years old) is known as a Tauri star while those with greater mass
are Herbig stars.
The newly formed stars emit jets of superheated gases along their axis of
rotation.
Stars spend about 90% of their existence fusing
hydrogen into helium in high-temperature and high-pressure. Stars in this phase
are said to be on the main sequence, and are called Dwarf stars. Our Sun, the closest star to the earth is also a
dwarf star which is 4.5 billion years old. The time a star spends on the main
sequence depends primarily on the amount of fuel it has and the rate at which
it burns it. As stars exhaust their supply of hydrogen at their core, they
start to fuse hydrogen from a shell outside the helium core. This is when they are converted into Red Giants. Their outer layers expand
and cool in this phase. Eventually the core of the star will start to make ions.
This will cause the star to Collapse.
The future of the star is depended upon its size. The average star will become
a white dwarf star while the larger stars will create a huge nuclear explosion
called a supernova.
Stars are not scattered randomly through space.
They are gathered together into vast groups known as Galaxies. There are about
10 billion galaxies which can be observed. The number of stars in a galaxy on
an average is 100 billion. This makes a huge count of Shiners altogether.
The largest star that we know of is
called VY CanisMajoris while the smallest known star right now
is OGLE-TR-122b, a red dwarf star that's part of a binary stellar
system.
Amazing right? Keep Shining and following, the stars and us!
Ketaki Kardile
