tähien

Tähien is a Finnish word that translates to "stars" in English. The term is used to refer to the celestial bodies that are visible in the night sky, primarily those that are self-luminous and appear as points of light. These stars are part of the Milky Way galaxy and are composed primarily of hydrogen and helium, with trace amounts of heavier elements. They vary in size, temperature, and luminosity, ranging from small, cool red dwarfs to massive, hot blue giants.

Stars are the primary source of light and heat in the universe, and they play a crucial role in the formation and evolution of galaxies. They are born from the gravitational collapse of molecular clouds, a process that can take millions of years. Once a star reaches the main sequence stage, it fuses hydrogen into helium in its core, releasing energy that counteracts the force of gravity and maintains the star's stability.

The study of stars, known as stellar astronomy, involves observing their properties, such as their brightness, temperature, and spectral type, to understand their life cycles and the processes that govern their behavior. Stars can end their lives in various ways, depending on their mass. Low-mass stars, like the Sun, will eventually become white dwarfs, while more massive stars can explode as supernovae, leaving behind neutron stars or black holes.

Tähien have been a subject of fascination and inspiration for humans throughout history, appearing in mythology, literature, and art. They have also been used for navigation and timekeeping, with ancient civilizations developing complex systems to track the movements of the stars. Today, stars continue to be a focus of scientific research, with astronomers using advanced telescopes and instruments to study their properties and the role they play in the universe.