What is the chemical composition of the Sun? How do astronomers identify the types of elements it contains?

Flora. Fauna. Marine and aquatic life. Biodiversity. And humanity. All these living beings would not exist without the Sun. There will be no life on Earth without it. The Sun for billion years, every day, the Sun is the primary source of power and energy and light on Earth.

It is known as the largest and most massive object in the Solar System. It is nearly 100 Earth’s wide and could theoretically fit all the planets inside, almost 600 times.  The Sun is the biggest star, and is an enormous ball of extremely hot, mostly ionized gas, shining in its power. Unlike Earth, the Sun has no solid surface, nor does it have a solid core. (click here for more details)

To better understand the formation, structure, and evolution of the Sun, it is essential to know about its chemical composition. It would be a vital reference standard against which the elemental contents of other astronomical objects are compared.

So what is inside the Sun, and do the contents help explain how it got its enormous energy?  We had a clearer understanding of the Sun’s massive energy output early in the 20th century.  In 1925, Cecilia Payne analyzed the spectra of stars using statistical atomic theories related to temperature, density, and composition. She found out that the stars are mostly composed of light elements – hydrogen and helium. But her conclusion was not generally accepted until it was confirmed four years later by the noted American astronomer Henry Norris Russell.  Nevertheless, Payne’s research was the first shown in the thesis on astronomy in 1925, and the first woman to get a Ph.D. in astronomy in the United States. (click here for more details)

As explained by Radiation and Spectra, a star’s absorption line spectrum can help determine what elements are present in the Sun, since Sun is a star. Astronomers found out that the Sun contains the same elements as Earth but not in equal proportions.

The Sun is mostly composed of light elements. Spectroscopy, a technique used by scientists to analyze the absorption spectrum of the Sun to determine its chemical structure.

Meanwhile, the Sun can be divided into six regions: Corona, Chromosphere, Photosphere, Connective zone, Radiative zone, Core. Based on the atom count, the Sun is about 91% hydrogen, 8.1 % helium, and .1% heavier elements such as carbon and nitrogen. Due to the Sun’s extremely high temperature, which can reach more than 27 million degrees Fahrenheit (15 million degrees Celsius), these elements stay at the gas-like phase called plasma.

Nuclear fusion takes place in the Core that converts the hydrogen into helium, thus releasing vast amounts of energy. This energy released comes in the form of solar radiation, electricity, solar wind, and life-giving heat, and light.

The Sun is mostly composed of elements in the form of atoms, also with a small number of molecules in gas forms The Sun is true to hot that no matter can survive, whether in liquid or solid form. Besides, the temperature of the Sun, the atoms become ionized that is, stripped of one or more of their electrons. It results in a large number of free electrons and positively charged ions in the Sun, making it an electrically charged environment.

During the nineteenth century, the scientists observed a spectral line at 530.3 nanometers in the Sun’s outer atmosphere, called the corona. The scientists assumed that the line was a result of a new element found in the corona since it had never been seen before. Then it was then named Coronium. Sixty years later, the astronomers discovered that this emission was, in fact, due to highly ionized iron with 13 of its electrons stripped off.

Some elements present in the Sun are Carbon, Nitrogen, Oxygen, Neon, Silicon, Chromium, Calcium, and Sulfur. Astronomers call these elements as metals because anything heavier than helium they call as such. Most of the Sun’s heavier metals were formed in other stars at the end of their lives. Elements like gold and uranium were formed as stars many times more massive; thus, the Sun detonated in supernova explosions. (click here for more details)

Despite its enormous power and size, the Sun will not live forever. After about 6.5 billion years, it will run out of hydrogen and enlarge to enclose some nearer planets such as Mercury, Venus, and Earth. After that, it will shrink into a small star known as a white dwarf. In the meantime, the Sun will continue to play a critical role in the entire Solar System.