What do scientists classify in the universe?

Scientists classify various celestial objects and phenomena in the universe, including stars, planets, galaxies, and nebulae, based on their physical properties, composition, and behavior. They also categorize these objects into broader groups, such as stellar bodies, dark matter, and cosmic microwave background radiation. Additionally, classifications extend to the study of cosmic events like supernovae and black holes, helping to understand the universe's structure and evolution. This systematic classification aids in the organization of knowledge and enhances our understanding of the cosmos.