The Ultimate Guide To The Sun

What Is The Sun?

The Sun is a star that is located at the center of the solar system and all planets revolve around this star. It is the largest ball of hot plasma in the solar system that contains more than 99.8% of the total solar system’s mass. 

The Sun is about 70% hydrogen, 28% helium, and everything else amounts to less than 2%. It is by far the most important source that radiates energy, mainly ultraviolet light, visible light and infrared radiation on the Earth. When it comes to its size, the diameter of the Sun is about 109 times of the Earth or 139 million kilometers. 

Structure Of The Sun:

When it comes to the structure of the Sun, it contains the following mentioned layers:

• Core: It is the innermost 20% to 25% radius of the Sun and acts as the source of all its energy. The core has a very high temperature and due to high pressure, the material it is composed of is very dense. It is in the core of the Sun, where nuclear reactions take place.

• Radiative Zone: It is the transferring of radiation that allows the transport of energy from the core of the Sun to the regions surrounding it. This is how it travels from the Sun’s center to its outer regions and is hence named “radiative zone”.

• Convective Zone: It is between 70% of the radius of the Sun and a point nearby to the visible surface, where the Sun is cool and thus, enough is diffused for the convection to take place. This becomes the primary means of transferring heat outwards.

• Photosphere: It is the deepest part of the Sun and can be directly observed with visible light.

• Chromosphere: It is the layer present above the photosphere and is much thicker compared to the same. Now that the layer has low density it is impossible to observe it without narrowband filters.

• Corona: It is recorded as the biggest structure of the Sun and has a very low density. 

What Are The Characteristics Of The Sun?

When discussing the Characteristics of the Sun, these are mainly classified into two categories:

Orbital Characteristics:

Following mentioned are the orbital characteristics of the Sun:

• The mean distance of the Sun from the Earth is 1 au (approximately 1.496 x 10^8 km). When measuring in terms of light speed, the mean distance is 8 min 19 sec

• The visual brightness (V) of the Sun is around -26.74 

• The Sun’s absolute magnitude is 4.83

• G2V is the spectral classification (G) of the Sun.

• The metallicity angular size of the Sun (z) is 0.0122

• The angular size of the Sun is measured as 31.6 – 32.7 minutes of arc or 0.527 – 0.545 degrees.

Physical Characteristics:

Following mentioned are the physical characteristics of the Sun:

• The equatorial radius of the Sun is measured as 695,700 km, 696,342 km, or 109 times the Earth’s equatorial radius.

• The equatorial circumference of the Sun is measured as 4.379 x 10^6 km or 109 times of the Earth’s equatorial circumference.

• The flattening surface area of the Sun is around 9 x 10^-6

• The surface area of the Sun is around 6.09 x 10^12 km or 12,000 times of the Earth’s surface area.

• The volume of the Sun is 6.09 x 10^12 km or 1,300,000 times of the earth’s volume.

• The mass of the Sun is 1.9885 x 10^30 kg or 332,950 times of the Earth’s mass.

• The average density of the Sun is 1.408 g/cm3 or 0.255 times the Earth’s average density.

• The center density of the Sun is 162.2 g/cm3 or 12.4 times the Earth’s center density.

• The equatorial surface gravity of the Sun is 274 m/s2 or 28 times the earth’s equatorial surface gravity.

• The Sun’s temperature in the Center is almost 1.57 x 10^7 K, Photosphere is almost 5,772 K and Corona is approximately 5 x 10^6 K 

• The age of the Sun is 4.6 billion years (4.6 x 10^9 years).

Mentioning The Photospheric Composition of the Sun:

The Photospheric Composition of the Sun (by mass) is:

• Hydrogen = 73.46%

• Helium = 24.85%

• Oxygen = 0.77%

• Carbon = 0.29%

• Iron = 0.16%

• Neon = 0.12%

• Nitrogen = 0.09%

• Silicon = 0.07%

• Magnesium = 0.05%

Sulphur = 0.04%

Conclusion:

The Sun is a hot star- a glowing ball of gas without which it is not possible for the living things to survive on the Earth. The Sun is already 4.5 billion years old and can continue to survive for another 5 billion years. Aspirants preparing for the NDA exam must know the basic details about the Sun. It is this article that composes every important detail that a candidate is supposed to know about the Sun.