ABSTRACT
The Sun is a gigantic element of the solar system. In actual terms, it is a sphere comprising, essentially, hot gaseous matter. The diameter of the Sun is equal to 1.39 × 109 m and is at a distance of 1.5 × 1011 from the Earth. The Sun has an effective black body temperature Ts of about 5777 K and it accounts for about 99.86% mass of the solar system. The mean distance of the Sun from the Earth is nearly 149.6 million km and sunlight covers this distance in about 8 min and 19 s. This distance changes across the year ranging from a minimum of 147.1 million km on the perihelion to a maximum of 152.1 million km on the aphelion. In terms of the gaseous composition, the Sun has hydrogen equivalent to around 74% of its mass or 92% of its volume, followed up by helium (about 24% of mass, 7% of volume). In addition, it has trace quantities of other elements such as iron, nickel, oxygen, silicon, sulphur, magnesium, carbon, neon, calcium and chromium. Importantly, many fusion reactions occur on the Sun’s surface with the most prominent of these being hydrogen (i.e. four protons). These react to form helium; the mass of the helium nucleus is lower than that of four protons.
