Galaksija

Galaksija is a term used in astronomy to describe a vast, gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. Galaxies are fundamental building blocks of the universe, and billions of them are thought to exist. The term "galaxy" comes from the Greek word galaxias, meaning "milky," referring to our own Milky Way galaxy.

Galaxies vary greatly in size, shape, and composition. They can range from dwarf galaxies, containing only a few million stars, to giant galaxies with hundreds of trillions of stars. Their shapes are broadly categorized into spiral, elliptical, and irregular. Spiral galaxies, like our Milky Way, have a flattened disk with spiral arms emanating from a central bulge. Elliptical galaxies are smooth, featureless, and oval-shaped. Irregular galaxies lack a defined shape.

Within galaxies, stars are born, evolve, and die. These processes, along with the interactions between stars and gas clouds, shape the galaxy's structure and evolution over billions of years. Galaxies themselves can interact with each other, sometimes merging to form larger structures. The study of galaxies, known as extragalactic astronomy, is crucial for understanding the large-scale structure and evolution of the universe. Our Sun is just one of billions of stars in the Milky Way galaxy, which is part of the Local Group, a collection of galaxies that includes Andromeda and several smaller dwarf galaxies.