| Term: | Supermassive black holes |
| Definition: |
A black hole of tremendous mass, equivalent to those of millions or even billions of stars, which is believed to exist and occupy the centers of many galaxies. The supermassive black hole residing in the center of our Milky Way Galaxy is the object Sgr A* with a mass of 4 x 10^6 solar masses within a radius of 100 astronomical units. |