The nearest star to us, the Sun, is important in many ways. Not only does it help sustain life on Earth, but it also provides astrophysicists with information on how stars work. It is an average size star, and yet makes up 99.8% of the total mass of the Solar System. Studying it allows to determine the chemical composition of stars and understand the nuclear reactions that take place at the cores of stars.
At the center of the Sun, nuclear fusion takes place. Nuclear fusion reactions combust hydrogen into helium, providing the energy that the Sun radiates into space. However, this radiation does not happen immediately. Once hydrogen fusion happens at the core, energy travels to the outermost layer of the inside of the Sun, where hot gases carry all this energy towards the surface. All of this takes millions of years.
Stars bigger than the Sun don’t only burn hydrogen into helium. Red giants produce heavier elements by also burning helium and more, like carbon. A lot of elements are created this way. Up until Iron, all elements are produced at a star’s center. Our own star will one day also expand to become a red giant and start burning helium into heavier elements.
Solar Flares and sunspots
The Sun has a magnetic field that is very uneven, making the inside of the sun rotate faster than the surface. All of this movement causes phenomena like solar flares and sunspots. Solar flares are explosions happening at the surface due to concentrated magnetic energy. They usually happen near sunspots. Sunspots are dark spots caused again by a concentrated magnetic field at a particular point on the surface. They are colder than the rest of the surface, caused by all the irregularities in the magnetic field. There are also prominences, which is hot ionized gas around the surface trapped by the solar magnetic field. Prominences and sunspots can be seen during solar observations.
Even though we know that the Sun’s magnetic field is behind this, there are yet many things to uncover. For instance, sunspots have a periodicity of 11 years. This means that the number of sunspots observed has a solar cycle of 11 years. This has been observed and recorded many times, but we still do not know why. Why 11 years? And what causes this periodicity?
As can be seen, the Sun, even if it may seem like a mundane star compared to all the other stars in the Universe, has some very interesting features. Despite it being the nearest star and the easiest to study, we have many things to learn from it yet. There are still some things to figure out and study, as all of the questions have not quite been answered. This goes to show the extent of human knowledge, and how we have only scratched the surface of all the fascinating mysteries of the Universe.
Editor: Maria ‘Stefi’ Ticsa