TON 618: The Black Hole Lurking at the Very Edge of the Universe

Deep in the cosmos, billions of light-years away, lies TON 618, one of the most extraordinary objects ever discovered. Invisible to the naked eye, this cosmic giant is revealed through powerful telescopes as a hyperluminous quasar, fueled by a supermassive black hole that stretches the limits of our understanding of the universe.

TON 618 resides in the constellations Canes Venatici and Coma Berenices, far beyond the Milky Way. Despite its incredible distance, its immense brightness makes detailed observation possible for scientists.

TON 618 as a Quasar

TON 618 is classified as a quasar, the intensely bright and active center of a distant galaxy. Quasars shine because a supermassive black hole at their core pulls in surrounding gas and dust. As this material spirals inward, it heats up and emits vast amounts of energy.

This quasar is so luminous that it outshines the galaxy that hosts it, making TON 618 one of the brightest known objects in the universe.

The Black Hole at the Heart of TON 618

At the heart of TON 618 lies a black hole of staggering scale. Current estimates place its mass at roughly 66 billion times the mass of the Sun, making it one of the heaviest black holes ever discovered.

For comparison, the Milky Way’s central black hole, Sagittarius A*, is only about 4 million solar masses. TON 618’s black hole is roughly 16,500 times more massive. Its event horizon — the boundary beyond which nothing can escape — stretches around 1,300 astronomical units (AU). One AU is the distance from Earth to the Sun, meaning this black hole’s “edge” extends far beyond Neptune’s orbit.

The brightness of TON 618

TON 618 shines with an astonishing brightness of about 140 trillion times that of the Sun. This extreme luminosity arises as gas and dust accelerate toward the black hole, heating up and releasing enormous energy. It is precisely this energy that allows TON 618 to be visible across billions of light-years.

Astronomers determine the black hole’s mass by measuring the speed of gas orbiting the quasar: the faster the gas moves, the stronger the gravitational pull, and the more massive the black hole.