Galaxy | Definition, Formation, Types, Properties, & Facts | Britannica
The Mystery of Phantom Galaxies May Soon Be Solved - Scientific American
What is a galaxy?
What is a galaxy? | Live Science
What is a Galaxy? Definition and Types of Galaxies | Spiral Galaxies | BYJU'S
What is a galaxy? All you need to know
Stars and Galaxies Chapter 12. Stars Definition: a large ball of gas that emits energy produced by nuclear reactions in the star's interior Planets, comets, - ppt download
What Is a Galaxy? | NASA Space Place – NASA Science for Kids
Astronomers see galaxies in ultra-high definition - BBC News