Final answer:
The brightest type of active galactic nucleus is the quasar, with luminosities up to a hundred trillion times that of the Sun, far outshining other types of active galactic nuclei.
Step-by-step explanation:
The brightest type of active galactic nucleus is the quasar. Quasars are not just the most luminous types of active galactic nuclei, but they are also some of the most powerful and distant objects observed in the universe. They have luminosities reaching as much as a hundred trillion times that of our Sun (10¹⁴ Lsun), which is 10 to 100 times the brightness of even the most luminous elliptical galaxies. Quasars are known for their compact size and for being the energetic hearts of faraway galaxies. They can radiate energy across the electromagnetic spectrum, from radio waves to X-rays, and their energy output is believed to be powered by the accretion of material into supermassive black holes at their centers. While blazars, Seyfert galaxies, and radio galaxies are also types of active galactic nuclei, they lack the extreme luminosity characteristic of quasars.