Knowra Galaxy Galaxy A galaxy is a gravitationally bound system of stars, stellar remnants, gas, dust, and dark matter. Its structure and evolution reflect gravity, matter, and energy acting across immense scales.
Star : A self-gravitating object that produces energy through nuclear fusion in its interior. Stars supply most of a galaxy’s visible light and accumulate into its stellar component.
Galaxy formation : The assembly of galaxies from matter in the expanding universe, shaped by gravity and cosmic gas flows. It describes how the first galactic systems emerged from early density fluctuations.
Milky Way : The barred spiral galaxy that contains the Solar System. It is the galaxy whose stars and structure can be studied from within.
Spiral galaxy : A galaxy with a flattened rotating disk and prominent spiral arms. Its organized disk contrasts with the smoother appearance of elliptical systems.
Galaxy cluster : A gravitationally bound collection of galaxies, hot gas, and dark matter. Clusters show how galaxies assemble into larger gravitational systems.
Interstellar medium : The gas and dust between stars within a galaxy. This material provides the raw matter from which new stars form.
Galaxy evolution : The changes in a galaxy’s stars, gas, structure, and activity over cosmic time. Star formation, accretion, and interactions continually reshape galaxies.
Andromeda Galaxy : A large spiral galaxy about 2.5 million light-years from the Milky Way. Its approaching motion and scale make it a key example of a neighboring large galaxy.
Elliptical galaxy : A galaxy with a smooth, rounded shape and little cold gas compared with typical spiral galaxies. It represents a common galaxy form with less ongoing star formation.
Cosmic web : The universe’s large-scale network of matter arranged in filaments, sheets, and voids. Galaxies trace dense regions of this underlying cosmic structure.
Show all 27