Pluto did not meet the criteria to be defined as a full planet because of its size. Pluto met only two criteria that stop it from becoming a full planet. One of the criteria that almost made Pluto a planet orbit around the sun and it is round like a planet, but it did not clear the neighborhood orbit around it. The size is why Pluto was demoted to a dwarf planet.
Black holes are objects that are very hot and its surface gravity is so immense