The Sun (Important Facts) {Part-12}

THE SUN IS THE STAR AT THE CENTRE of the Solar System. It is about 5 billion years old and will continue to shine as it does now for about another 5 billion years.

The Sun

 The Sun is a Yellow Main Sequence Star(explained in the Previous Blog Part-7) about 1.4 million kilometers in diameter. It consists almost entirely of hydrogen and helium. In the Sun's core, hydrogen is converted to helium by nuclear fusion, releasing energy in the process. The energy travels from the core, through the Radiative and Convective Zones, to the Photosphere (visible surface), where it leaves the Sun in the form of heat and light. On the Photosphere there are often dark, relatively cool areas called Sunspot, which usually appear in pairs or groups and are caused by the Cooling effect of Magnetic Field.

Internal and External Structure of the Sun

Other types of solar activity are Flares, which are usually associated with the Sunspots, and Prominences. Flares  are sudden discharge of high-energy radiation and atomic particles. Prominences are huge loops or filaments of gas extending into the solar atmosphere; some last for hours, others for months. Beyond the Photosphere is the Chromosphere (inner atmosphere) and the rarified Corona (outer atmosphere), which extends millions of kilometers into space. Tiny particles that escape from the Corona  give rise to the Solar Wind, which streams through space at hundreds of kilometers per sec. The Chromosphere and Corona can be seen from earth when the Sun is totally eclipsed by the Moon.

How a Solar Eclipse occrs

Total Solar Eclipse

Temperature of the Sun