The heaviest known object in the universe is a matter of ongoing scientific research and discovery. However, the heaviest known objects in the universe are supermassive black holes that reside at the centers of galaxies.
These black holes have incredibly large masses, ranging from millions to billions of times the mass of our Sun. For example, the black hole at the center of our own Milky Way galaxy, called Sagittarius A*, has a mass of about 4 million times that of the Sun.
It's important to note that our understanding of the universe is constantly evolving, and new discoveries can be made. So, the knowledge regarding the heaviest known object in the universe may have been updated since then.