Tähdetä

Tähdetä is a Finnish word that translates to "star" in English. It is used to refer to a celestial body that is a luminous sphere of plasma held together by its own gravity. Stars are the most visible celestial objects in the night sky and are a common feature of many cultures' mythologies and folklore. They are primarily composed of hydrogen and helium, with trace amounts of heavier elements.

Stars vary greatly in size, temperature, and brightness. The Sun, our closest star, is a medium-sized star with a surface temperature of about 5,500 degrees Celsius and a diameter of about 1.4 million kilometers. Other stars can be much larger or smaller, with some being hundreds of times the size of the Sun and others being only a fraction of its size.

Stars are born from the collapse of massive clouds of gas and dust, a process known as stellar nucleosynthesis. Over time, stars generate energy through nuclear fusion, converting hydrogen into helium and other elements. This process releases a tremendous amount of energy, which is what makes stars shine.

Stars also play a crucial role in the universe's evolution. They are the primary source of light and heat, and their deaths, in the form of supernovae, distribute heavy elements throughout the cosmos, which are essential for the formation of planets and life.