Black holes are on a continuum of ultradense objects that form from the remnant cores of dead stars after they run out of fuel and collapse under gravity. White dwarfs form from stars up to about eight times the mass of the Sun, and have an upper mass limit of about 1.4 times the Sun's mass.

Two mighty beams of energy have been detected shooting in opposite directions from a supermassive black hole inside a distant galaxy - the largest such jets ever spotted, extending about 140 times the diameter of our vast Milky Way galaxy.