Spiral nebulas, also known as spiral galaxies, are fascinating celestial bodies found throughout the universe. These nebulas are characterized by their swirling, spiral-like shapes, which are created by the gravitational pull of the stars and gas within them. Synonyms for spiral nebulas include spiral galaxies, spiral nebulae, and galactic spirals. Additionally, some scientists use the term "spiral arms" to refer to the swirling structures within a spiral nebula. These structures are often comprised of gas, dust, and young stars, which are constantly being born and dying within the galaxy. Overall, the study of spiral nebulas provides valuable insights into the formation and evolution of galaxies within our universe.