What is a supermassive black hole?

A supermassive black hole is characterized by its incredibly large mass, which ranges from millions to billions of times that of the Sun. These black holes are typically found at the center of galaxies, including our own Milky Way, and their immense gravitational pull plays a crucial role in the structure and dynamics of galaxies. The formation of supermassive black holes is still an area of active research, with theories suggesting that they may evolve from smaller black holes or form directly from the collapse of massive gas clouds in the early universe.

The other choices do not accurately describe a supermassive black hole. A black hole formed from a single star typically refers to stellar black holes, which are much smaller in mass. A black hole with the mass of a neutron star indicates a significantly lower mass than what defines a supermassive black hole. Lastly, a black hole containing no matter contradicts the fundamental nature of black holes, which are formed from collapsing masses, leading to the conclusion that supermassive black holes are, indeed, packed with immense gravitational energy due to their substantial mass.