Sun

The sun is a burning gas ball. Its radiation makes life on our Earth possible. It is also the closest star to Earth and is also the brightest object in the sky. The sun is in the centre of the solar system. The Earth always revolves around the sun in one year.

Place of the Sun in the Universe

The sun is about 27,000 light-years from the centre of our galaxy, the galaxy to which the Earth belongs, in the approximately 3,000 light-year-thick galactic disk and 1 AE (about 150 million kilometres) from Earth. The sunlight takes about 8 minutes and 20 seconds to reach the earth. The sun moves at a speed of about 220 km/sec in an orbit around the centre of our galaxy.

To get a picture: If we were to reduce the size of the solar system so that the sun is 1 metre in size, then the earth would be 9mm in size and 107 metres away from the sun.

Functioning of the sun

The Sun is a 4.6 billion-year-old star located in the galaxy of the Milky Way. It is a huge sphere of hot plasma. It consists of three parts: the core, the radiation zone and the convection zone. Nuclear reactions occur in the core. Hydrogen nuclei are converted into helium nuclei there. The energy moves in the form of photons, through the nucleus to the radiation zone. Photons are a form of electromagnetic radiation. Energy transport takes place in the convection zone.

The planets revolve around the sun. They each follow their own job.

Light from the sun

In the centre of the sun, atoms collide with each other, converting hydrogen into helium. This is called nuclear fusion.

Two hydrogen protons collide and then hydrogen is formed with a neutron and a proton. That's called deuterium (deux is two in French, so 2 particles). When deuterium collides with a hydrogen proton, helium 3 is formed. This releases a photon (in picture Gamma ray).

A gamma ray is actually a photon with a lot of energy. The photon already loses a lot of energy before it reaches the surface of the sun. The photons travel (at the speed of light) through space to Earth. Here we can see light

Characterize

Within the Milky Way it is an inconspicuous, more or less average star, on the other hand, the Sun is larger than 80% of all stars. This is because most stars are red-dwarf stars, and they are smaller than our Sun. It is the largest object in our solar system with an average diameter of about 1,392,000 kilometres and contains 99.87% of the mass of our entire solar system. On the surface of the sun, the temperature is about 5500 degrees (5800 Kelvin). There are also sunspots and it's a bit cooler there. In the core (the innermost) of the sun, it is much hotter, namely about 15 million degrees Celsius, or 15.5 million Kelvin.

The sun itself consists mainly of hydrogen, about 70%. The rest of the mass consists of helium (25%) and other particles (5%). Researchers can see which substances the remaining particles are. A ray of sunshine consists of different colours. When a sunbeam passes through a prism, you see the colours. A kind of rainbow. If these colours are visible side by side, there are all black lines between them and in the colours. When zooming in on the black lines, these are a kind of barcodes. These barcodes indicate substances. This way, researchers can see what other substances are in the sun.

Stars are divided into a number of categories. Our sun is a yellow dwarf.

Life cycle of the sun

Origin of the sun

The sun is said to have formed about 4.6 billion years ago by the contraction of an extensive cold, gaseous Or nebula. This happened due to the gravity that arose when the middle of the nebula got closer together. The whole process of contraction will have taken about 35 million years. Eventually, the pressure and temperature in the centre of the gas bulb became so high - millions of degrees - that nuclear reactions could begin there. The sun was born.

The sun as the main series star

Over a period of 12 billion years, the sun receives its energy from nuclear fusion. Due to the high pressure and temperature in the core of the star, the hydrogen can be converted into helium (so-called hydrogen combustion'). In this process, energy is released. This is the sun as we know it now and is about 4.6 billion years old and is estimated to shine for about 7 billion years. The sun is a stable main sequence star during this period. The energy that radiates outwards is in balance with the gravity that works inward.

Dese of the sun

In an estimated 5 billion years' time, hydrogen will run out in the sun. As a result, the outward energy is less and the gravity contracts the sun harder. Due to the pressure and rising temperature, it gets even hotter in the sun. Helium is also now beginning to fuse, in heavier elements such as carbon. The energy to the outside is now becoming extremely strong! This causes the sun to swell and become larger and shine much more brightly. The sun is now called a: Red Giant. The sun loses the balance between the outflow of energy and the inward gravity. The outer layers of the sun are blown away. What remains of the Sun is now compressed by gravity into a small sphere, about the size of the Earth: a White Dwarf (more or less the deep core of the sun that remains). All particles are so firmly on each other that a teaspoon of a White Dwarf weighs millions of kilos. The process from the current sun to White Dwarf takes millions of years.

The White Dwarf Sun shines with the last heat it has left. When the Sun has lost all heat (the Sun is then 0 kelvin) it becomes a black dwarf (the remnants of a star). The transition from a White Dwarf to a Black Dwarf can take hundreds of billions of years. That is also the reason that scientists think that there are currently no Black Dwarfs in our universe.

The previously blown away, outer layers of sun fly through space like a new nebula. This nebula can create new stars and even planets, just like our solar system almost 5 billion years ago.

Consequences for the earth when the sun dies

There are several theories about what will happen to the earth when the sun falls out. A number are explained here.

When the sun goes out, it gets completely dark on earth. In the following minutes it gets colder and colder and after half an hour the temperature will have already dropped by 1 to 2 °C. With no sun for 1 day, the temperature has dropped by 3 °C all over the world. This is especially bad for the plants. Plants need light for photosynthesis. They can no longer carry this out, the plants will die. After about 1 week the earth will have reached freezing, almost all crops will be dead. At about 1 year of the sun's death, the earth will have an armour of ice. The average temperature is about -73 °C and there is no more life on Earth.

Most researchers believe that the sun still has about 5 billion years to live. The dying process has a large impact on other planets in our solar system. Most planets are attracted to the sun as it is dying. Eventually, the planets are eaten by the sun. Except small rocky planets. These planets are likely to be pushed away from the sun when it is dying. It is different for the earth. The earth has a layered inner core, which makes it much more complex to achieve this. But the chance is that the earth will also be pushed away.

In addition, the sun can also get bigger and bigger during dying. As a result, he eats up the planets Mercury and Venus. This can also happen to the earth. However, researchers think that the earth will end up in a different orbit, so that we are not swallowed up. Researchers do not yet know whether we can still live on earth.

Influences of the sun

The sun as a source of energy

So nuclear fusion takes place in the core of the sun, releasing energy. We experience this energy mainly in the form of light and heat. This energy is important for a huge number of processes on Earth. The sun, together with the atmosphere, ensures that it is warm enough on Earth. Plants use the sun, for example, for photosynthesis, to create food. The water cycle also happens under the influence of the sun.

Today, man is trying to make the best possible use of the sun's energy, such as solar energy. This is an important option for renewable energy

The sun as God

Since the distant past, the sun has had an influence on people's lives. She realised that the sun was so important that they gave it divine powers. In many ancient cultures, such as those of the Egyptians, the Greeks, the Romans and the Germans, she had an important position as a Divine being in various myths.

Our solar system

The Earth and all other planets, which include both the earth planets and the gas giants, revolve around the sun, orbited by gravity. In terms of size and mass, the Sun is the dominant member; the mass is more than 330,000 Earth's masses, the volume is more than 1.3 million times that of the Earth. The entire orbit of the moon around the earth could be in the solar body in terms of size.

Other bodies that revolve around the sun include asteroids, meteoroids, comets, and dust.

Looking at the sun

If you want to look at the sun during a solar eclipse or in other situations, you should never do so with the naked eye. After a few seconds, damage to your eye will occur and if you are unlucky, it will be there for the rest of your life. Use welding glasses or specially made glasses. Other dark materials such as black slide or photo film can still pass through a lot of harmful infrared and ultraviolet light.

It goes without saying that you have to be much more careful when using binoculars or a telescope. If a burning glass can burn a piece of paper in a few seconds, it can also happen to your eyes. The safest way to observe with a telescope is to project the solar image on a piece of white paper, and thus indirectly view the sun.

You can see the sun with a Lunt telescope, which you can see at the observatory. With the Lunt telescope you can view the surface of the sun and you can see the colour codes of the sun.