How did we learn about the Sun?

We have sent several solar missions into space to study the Sun and its characteristics. The first detailed observations were made by NASA’s Pioneer missions that were launched between 1959 and 1968. The Solar Maximum mission of 1980 made a detailed study of solar flares. The Solar and Heliospheric Observatory (SOHO) launched in 1995, has been continuously collecting data regarding the Sun for the last ten years.

The Sun takes about 26 days on average to rotate on its axis. Since it is made up of gas, different parts of the Sun rotateat different speeds. The surface closest to the equator rotates faster than that closest to the polar regions. The Sun’ssurface near the poles takes almost 36 days to complete one rotation.

Is the Sun really a star?

The Sun is a medium-sized star known as a yellow dwarf. It is younger and smaller than most stars in the universe, but is very bright and extremely hot. In about five billion years, when all the hydrogen in its core has been used up, the Sun will change into a red giant star. After that, the Sun will evolve into a white dwarf before finally dying out.

What is a solar flare?

Sometimes the Sun produces a huge amount of magnetic energy that sends out jets of gas into space. These jets of gas arecalled solar flares and cause a sudden increase in the brightness of the Sun. Solar flares are often followed by the release of electrically charged particles like protons and electrons. These are called solar winds and are known to travel at a speed of about 500 kilometres (300 miles) per second.

What is a solar eclipse?

A solar eclipse occurs when the Moon comes between the Sun and the Earth, blocking the Sun from our view. In a total solar eclipse, the Moon blocks out the Sun from our view completely. In a partial eclipse, however, a part of the Sun is visible. During an annular eclipse, we can see a small ring of the Sun glowing around the Moon. When the Moon is nearer to the Earth it appears larger and therefore covers the Sun completely, although it is actually much smaller than the Sun. However, in an annular eclipse the Moon is too far away from the Earth to block the Sun out totally and therefore a ring of sunlight is seen.

How was the Sun created?

Before it was formed, the Sun and the rest of the solar system was a huge mass of hot gas and dust called a solar nebula. This nebula spun faster and faster until the clouds of gases, dust and ice particles clumped together and exploded, forming the sun.

What is Sun?

Our solar system is made up of the Sun, eight planets, three dwarf planets and many asteroids, comets and other space rocksThe Sun is the largest object in the solar system and is located right at its centre. The planets, dwarf planets, asteroids and comets travel around the Sun in an ellipse. Our solar system was formed about 5 billion years ago, and the surface of the Sun is about 4.6 billion years old.

What are Heavenly pictures?

By drawing imaginary lines between the stars in the sky, you will notice the shapes of animals or objects familiar to you. You might see a crab, a dragon, a bear or other patterns. These star patterns are called constellations. Astronomers haveidentified 88 constellations in all. The more famous ones are the Great Bear, the Little Bear and Orion, also known as theHunter. The constellations also include characters from Greek mythology and the 12 signs of the zodiac.

What is a black hole?

Black holes are extremely compact space objects that were once massive stars. Sometimes a huge star begins to shrink until it is smaller than an atom. This is called a black hole. The centre of the black hole is called ‘singularity’.

The gravity near this point is so strong that any object that gets too close to the black hole is pulled into it. Even light gets sucked into it, which is why we can’t see a black hole. Scientists use special instruments to detect a black hole’spresence. They examine the effects it has on the objects near it.

Nobody can actually see a black hole, because the extremely strong gravity inside them does not even allow any light to escape, let alone anything else.This is an artist’s impression of what a black hole may be like.

What is a white dwarf?

A small star usually shrinks to form a dense white dwarf. The size of a white dwarf is similar to the size of Earth. There are many white dwarfs in our galaxy but they are too dim to be seen. Sirius B is one of them.

How long does a star live?

A star glows for millions of years until the gases in its outer layer begin to cool, and the hydrogen in the inner core is slowly used up. The cool outer layer starts to glow red. When this happens the star is called a red giant. The red giant continues to lose its brightness until it fades away. Depending on its size, a red giant may die in an explosion, get compressed to form a black hole or become a white dwarf.

What is a protostar?

Stars are born in clouds of dust and gases, mainly hydrogen. More and more gas is pulled together by gravity to form a cloud. After a while the cloud begins to spin. This makes the gas atoms bump into each other at high speeds, creating a great deal of heat. As the cloud becomes hotter a nuclear reaction takes place inside, and the cloud begins to glow. This glowing cloud is called a protostar. The protostar continues to contract until it becomes a star.

What is a Star?

A star is a huge ball of gas and dust that gives out both heat and light. When the gases in the star burn out, it dies. A star can live for millions, even billions, of years depending on its size. Each galaxy in the universe is made up of several billion stars.