A supermassive black hole 9 billion light-years away appears to have a companion black hole orbiting around it. As the orbit shrinks, the pair gets closer to merging.

Dual black holes are rare enough, but duelling black holes? Astronomers have discovered that two black holes 1.2 billion light-years from Earth are gearing up for a cataclysmic merger as soon as 100 days from now. The event, if it happens, would be momentous for astronomy, offering a glimpse of a long-predicted, but never witnessed mechanism for black hole growth. It might also unleash an explosion of light across the electromagnetic spectrum, as well as a surge of gravitational waves and ghostly particles called neutrinos that could reveal intimate details of the collision.

The technology to be used is the same that led to the verification of gravitational waves in 2016.

According to Encyclopedia Britannica, a black hole is “cosmic body of extremely intense gravity from which nothing, not even light, can escape. A black hole can be formed by the death of a massive star. When such a star has exhausted the internal thermonuclear fuels in its core at the end of its life , the core becomes unstable and gravitationally collapses inward upon itself, and the star’s outer layers are blown away.”

As with many statements recorded about astronomy, this one didn’t age well. Black holes do emit light, just not very much of it. Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole’s event horizon. This infrared emission is detectable, and black holes have since been visually observed.

Black hole pairs are rare and difficult to detect. Most are hundreds of light-years apart and unlikely to collide for hundreds of millenia. This pair of black holes could conceivably collide before summer.

AGNs= Active Galactic Nucleus

Supermassive black holes are thought to lurk at the heart of most, if not all, galaxies, but theorists don’t know how they grow so big. Some sporadically suck in surrounding material, fiercely heating it and causing the galaxy to shine brightly as a so-called active galactic nucleus (AGN). But the trickle of material may not be enough to account for the black holes’ bulk. They could gain weight more quickly through mergers: After galaxies collide, their central black holes become gravitationally bound and they gradually spiral together.

Scott Ransom of the National Radio Astronomy Observatory admitted AGNs “do all sorts of crazy things we don’t understand. We really don’t know what to expect.”

Black holes, in many ways, are still a scientific mystery. This collision will help astronomers solve that mysytery. Scientists all over the world, as well as scientists off-world, on the International Space Station, will be observing. We’ll share more information as soon as we have it.

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