tähti

Tähti is the Finnish word for star. In astronomy it denotes a luminous sphere of plasma that emits light and heat, produced by nuclear fusion in its core. In everyday speech, tähti also refers to a star-shaped symbol used in writing and typography, and to stars as symbols of fame, excellence, or guidance. The plural form is tähdet.

Most stars form in clouds of gas and dust when gravity causes collapse and the core heats up. Hydrogen fuses into helium, releasing energy that powers the star for millions to billions of years. Stars vary in mass, temperature, and color, from cool red dwarfs to hot blue giants. The Sun is a mid-sized, G-type star that anchors the Earth’s solar system.

Astrophysicists study stars to understand their life cycles, compositions, and the processes that create heavier elements. Distances to stars are measured in light-years, and nearby stars are mapped by stellar parallax. In galaxies, stars form in regions of star formation and end their lives as white dwarfs, neutron stars, or black holes, depending on initial mass.

Beyond science, tähti is used in everyday Finnish to describe ratings and achievements (for example, five stars). The symbol * is called asteriski in Finnish, a term used for the asterisk; the word tähti is also used colloquially to refer to the star-shaped symbol. Thus, tähti covers both the astronomical object and its symbolic representations in culture and communication.