THE SUN

The Sun is 150 million kilometers (93 million miles) away from the Earth (this distance varies slightly throughout the year, because the Earth’s orbit is an ellipse and not a perfect circle).

The Sun is an average star – there are other stars which are much hotter or much cooler, and intrinsically much brighter or fainter. However, since it is by far the closest star to the Earth, it looks bigger and brighter in our sky than any other star. With a diameter of about 1.4 million kilometers (860,000 miles) it would take 110 Earths strung together to be as long as the diameter of the Sun.

The Sun is mostly made up of hydrogen (about 92.1% of the number of atoms, 75% of the mass). Helium can also be found in the Sun (7.8% of the number of atoms and 25% of the mass). The other 0.1% is made up of heavier elements, mainly carbon, nitrogen, oxygen, neon, magnesium, silicon and iron. The Sun is neither a solid nor a gas but is actually plasma. This plasma is tenuous and gaseous near the surface, but gets denser down towards the Sun’s fusion core.

Stars like the Sun shine for nine to ten billion years. The Sun is about 4.5 billion years old, judging by the age of moon rocks. Based on this information, current astrophysical theory predicts that the Sun will become a red giant in about five billion (5,000,000,000) years.

SIZE OF THE SUN

The size of the Sun compared to the largest known stars (red giants) is not very big. However, if compared to the most common type of star in the universe, the red dwarf, the Sun is quite a bit larger. Thus, the Sun is not the biggest type of star in the universe, but it is definitely larger than most.

As far as the Sun’s mass compared to other bodies found in our solar system, the Sun is easily the most massive. The Sun alone contains 99.8% of the total mass in the Solar System.

In terms of size, the Sun has a diameter of roughly 1.4 million kilometers (870,000 miles). To put this in perspective, this is almost 110 times the diameter of the Earth. What this means is that about one million Earth’s could fit inside the Sun.

WHAT TYPE OF STAR IS THE SUN?

Although we think of our Sun as a unique celestial body, it is, in fact, one of trillions of stars in the universe. On top of this, the Sun is rather ordinary as far as stars go. The official classification for our Sun is G V star (often referred to as a Yellow Dwarf star), which means that it is a main sequence star whose surface temperature is between 5027°C and 5727°C.

Some estimates for stars similar to the Sun in the Milky Waygalaxy alone are as high as 7 billion. If this number is correct, there could be over one trillion stars that are roughly the same as our Sun in the universe.

FACTS ABOUT THE SUN

The Sun accounts for 99.86% of the mass in the solar system. It has a mass of around 330,000 times that of Earth. It is three quarters hydrogen and most of its remaining mass is helium.
Over one million Earth’s could fit inside the Sun. If you were to fill a hollow Sun with spherical Earths, somewhere around 960,000 would fit inside. However, if you squashed those Earths to ensure there was no wasted space then you could fit 1,300,000 Earths inside the Sun. The surface area of the Sun is 11,990 times that of Earth.
One day the Sun will consume the Earth. The Sun will continue to burn for about 130 million years after it burns through all of its hydrogen, instead burning helium. During this time it will expand to such a size that it will engulf Mercury, Venus, and Earth. When it reaches this point, it will have become a red giant star.
The energy created by the Sun’s core is nuclear fusion.This huge amount of energy is produced when four hydrogen nuclei are combined into one helium nucleus.
The Sun is almost a perfect sphere. Considering the sheer size of the Sun, there is only a 10 km difference in its polar and equatorial diameters – this makes it the closest thing to a perfect sphere observed in nature.
The Sun is travelling at 220 km per second. It is around 24,000-26,000 light-years from the galactic centre and it takes the Sun approximately 225-250 million years to complete one orbit of the centre of the Milky Way.
The Sun will eventually be about the size of Earth.Once the Sun has completed its red giant phase, it will collapse. It’s huge mass will be retained, but it will have a volume similar to that of Earth. When that happens, it will be known as a white dwarf.
It takes eight minutes for light reach Earth from the Sun. The average distance from the Sun to the Earth is about 150 million km. Light travels at 300,000 km per second so dividing one by the other gives you 500 seconds – eight minutes and twenty seconds. This energy can reach Earth in mere minutes, but it takes millions of years to travel from the Sun’s core to its surface.
The Sun is halfway through its life. At 4.5 billion years old, the Sun has burned off around half of its hydrogen stores and has enough left to continue burning hydrogen for another 5 billion years. Currently the Sun is a yellow dwarf star.

DOES THE SUN HAVE ANOTHER NAME?

While our Sun does not have an official scientific name, it does have another common name: Sol. This name originates from the ancient Roman’s god of the Sun, Sol. This alternate name is where we get the term “solar system,” which literally means system of the Sun.