The Sun is the most powerful star in our solar system. Its temperature is incredibly hot, reaching 27 million degrees Fahrenheit (15 million degrees Celsius) in the core.
This is where nuclear reactions, where hydrogen is fused to form helium, fuel the heat and light in the Sun. The Sun is also known for its many eruptions, such as solar flares and coronal mass ejections.
The Sun’s Size
The Sun is a massive ball of hydrogen and helium held together by its own gravity. It is 864,400 miles (1,391,000 kilometers) across and weighs 333,000 times as much as Earth.
It is the largest star in our solar system and, with an estimated lifetime of 4.5 billion years, it will continue to get bigger. As it ages, it will use up its hydrogen supply at its core and become a red giant, expanding beyond the orbit of Mercury, Venus and Earth.
This expansion will leave behind a dead core of carbon, oxygen and helium. It will then become a white dwarf star, which is about the size of Earth.
To illustrate how big the Sun is, students can build a model using an exercise ball and a small marble. Then they can walk the distance from the model to the Earth, which will give them a sense of how much smaller it is in reality than in their model.
You can also ask younger students to put their hands into a box full of 1 million earth balls and see how many they can fit inside the Sun. This will help them understand that the Earth is a tiny circle compared to the Sun, which is a very big sphere of hydrogen and helium.
The sun is also very hot, with temperatures exceeding 27 million degF (15 million degC). Its hottest part is its core, where nuclear reactions that fuse hydrogen to helium power the heat and light.
The Sun’s fusion reactions will last only about 5 billion years, at which point it will run out of fuel and shrink. When it does, it will puff up into a red giant, engulfing Mercury and Venus and possibly the Earth, before becoming a white dwarf.
The Sun’s Mass
The Sun’s mass is about 333000 times the mass of Earth (MEarth), or 1047 times the mass of Jupiter (MJ). It has a surface gravity of 274 m/s2 and a mean density of 1410 kg/m3, making it about 2.4 times heavier than water.
Astronomers use the mass of the Sun to calculate how strong its gravity is and to determine the orbital distance and speed of planets like Earth. The mass is also important for understanding how fast the solar wind blows away from the sun.
Scientists estimate that the sun loses around 4,000,000,000 kg per second to convert its energy into sunlight. This sounds a lot, but it’s actually a tiny fraction of the total mass.
For the most part, the Sun maintains its size by balancing its gravity on the inside with its fusion reactions at the core. As the sun gets closer to its end of life, however, it starts losing energy faster than it can replenish it. This leads to a loss of about 0.03% of the sun’s mass each year.
The sun’s energy is transferred from its core to the top of the Sun through a process called thermal radiation. This radiation is the result of photons released in the Sun’s core travelling a short distance, being absorbed by ions at the surface, and then being released again.
Another way that the Sun gets its energy is by releasing helium into space. This helium is then transformed into hydrogen by a process known as nuclear fusion.
This fusion is also the cause of the sun’s heat and its ability to radiate energy into space. This is why the sun’s atmosphere is so thick — it has to protect the sun from the intense radiation from the inside.
The Sun is made up of layers of hydrogen and helium gases. Each layer has a different purpose. For example, the outer layers are responsible for absorbing the UV light from the planets, while the inner layers act as a heat source and a fuel.
The Sun’s Radius
The Sun is a medium sized star that lies on the main sequence of stars in our Milky Way galaxy. It has a mass of 1.989 x 1030 kilograms and a radius of
The sun is also the dominant source of light and heat in our solar system. Its radiance supports almost all life on Earth and drives our climate and weather.
As a result, scientists often discuss the Sun’s size using the solar radius. This is a fundamental unit of size that astronomers use to classify stars.
Astronomers can calculate the sun’s radius by subtracting its distance from its center from its diameter, which is equal to
This density is then converted into a number of other units, including light-years. This is because light travels through space at a rate of 2.99792 x 108 metres per second, or about 149.6 million kilometers per hour.
Scientists also need to consider the sun’s gravity and its density. These factors affect the amount of energy that the Sun transfers to the solar system. The mass of the Sun is 1.989 x 1030 kg, while its surface gravity is 274 m/s2, which is 28.0 times that of the Earth.
Another factor that can impact the size of a star is its temperature. Many of the brightest and largest stars in our galaxy are G-type, which means they are cooler than our Sun.
These stars are much more stable than our Sun and have likely had planets orbiting them for a long time. These stars include UY Scuti, WHO G64, Mu Cephei and RW Cephei.
Some of the most massive stars in our galaxy are red hypergiants, which are very bright stars that have a very large size relative to the Sun. A star known as VY Canis Majoris, for example, is more than 1800 times the size of the Sun and has a radius of around 2.100 km. This star has been observed to host billions of planets, and it is possible that some of these planets may be able to support life.
The Sun’s Density
The Sun is a dense star, made up of primarily hydrogen and helium. Hydrogen is the lightest of the six elements and helium is about twice as heavy. The Sun’s density is about 1.41 g/cm3, making it a little less dense than the other planets in our solar system.
There are also seven other elements in the Sun: oxygen, carbon, neon, nitrogen, magnesium, iron and silicon. Each atom of a single element in the Sun has 98,000 helium ions, 850 oxygen ions, 360 carbon ions, 120 neon ions, 110 nitrogen ions and 40 magnesium ions.
A significant amount of energy in the Sun comes from nuclear fusion within its core, which generates neutrinos and solar radiation. At present, the Sun is in its main sequence phase and is converting about four million tonnes of matter into energy each second.
This rate of conversion is more than 200 times the mass of our Earth, and it’s one of the major sources of energy in the Solar System. It also creates a magnetic sphere called the heliosphere, which extends into interplanetary space.
As the Sun heats up, it radiates its energy as light and ultraviolet radiation. This is the most important source of energy for life on Earth.
The Sun’s temperature ranges from 6000 Kelvin (or 5700 degrees Celsius) at the top of its photosphere to almost 100 million Kelvin at its core. Temperatures vary a lot over time, and the Sun’s output of heat has changed a great deal since its formation 4.57 billion years ago.
Another important source of energy in the Sun is convection, which occurs throughout the outer 15% of its radius. Similar to water boiling in a pot or hot wax in a lava lamp, gases deep in the Sun’s convective zone are heated and then “boil” outward away from the core in thermal columns. When the gases reach their limits, they cool down and plunge back to the base of the convective zone.
In this experiment, students will learn how to work with large numbers by calculating how many Earth-sized balls would fit into the Sun if it were squeezed together and without space between them. They will be able to estimate that the number varies between 1.3 and 1 million, and they can use this information to build a model of the Sun that is filled with nearly 1 million Earth-sized balls.