What is a spiral galaxy?
Q: What is a spiral galaxy?
A: A spiral galaxy is a galaxy that has a flat, rotating disk with a bulge in the center and spiral patterns extending outward from the bulge.
Q: What does a spiral galaxy contain?
A: A spiral galaxy contains stars, gas, dust, dark matter, and a supermassive black hole at its center.
Q: What were galaxies long thought to be?
A: Galaxies were long thought to be nebulae.
Q: Who first described the spiral nebula as a type?
A: Edwin Hubble first described the spiral nebula as a type in his 1936 work The Realm of the Nebulae.
Q: What is a barred spiral galaxy?
A: A barred spiral galaxy is an important and common type of spiral galaxy.
Q: What are the three other kinds of spiral galaxies?
A: The three other kinds of spiral galaxies are grand-design spiral galaxies, multiple-arm spiral galaxies, and flocculent spiral galaxies.
Q: Where are spiral and irregular galaxies mostly found?
A: Spiral and irregular galaxies are mostly found in low-density parts of the universe and are rare in the centers of galaxy clusters.
