Black holes: Objects formed when massive stars collapse due to gravity.
Supermassive Black Hole: Black Holes found in the center of galaxies. They are up to billions of times more massive than the sun
•There are 4 main types of galaxies: spiral, lenticular, elliptical, and irregular.
Spirals: have a bulge at the center and arms of stars, gas, and dust
Lenticular: spiral galaxies that contain a bulge, but lack arms (look like disks)
Elliptical: have a bright central region with a halo of gas and dust around it (spheroid or egg-shaped)
Irregulars: have no clearly defined shape (merging galaxies may exhibit irregularities)