In a rare astronomical event, scientists have observed light from the merger of two black holes in the distant universe. The event is significant since black holes are known to not allow light to pass through them.

The new observation has opened a door for scientists to glimpse deep into the worst villains of the universe that dominate the development of galaxies. If confirmed, it could be the first known light flare from a pair of colliding black holes.

Nasa has released a conceptual visualisation of the event that shows a supermassive black hole surrounded by a disk of gas. Embedded in this disk are two smaller black holes that may have merged to form a new black hole.

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The observation was conducted using Caltech’s Zwicky Transient Facility (ZTF) located at Palomar Observatory near San Diego. Scientists are hopeful that this may be the first such scenario among many that could be observed in the future.

The merger of the two black holes was first spotted on May 21, 2019, by two gravitational wave detectors – the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory, or LIGO, and the European Virgo detector – in an event called GW190521g. Scientists looked for light signals from the merger at the location where the gravitational wave signal originated.

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Astronomers had in June observed light behind a black hole. In a research published in the journal Nature, astronomers reported the observations of X-ray flares emitted from around the supermassive black hole and its accretion disk.

The light was detected by coincidence when researchers were studying the feature known as the corona. It is a form of X-Ray light that is formed by materials falling into a supermassive black hole that can be analysed to map and characterise them.

What is a black hole?

Black Hole is formed from the death of a star with such a high gravitational field that the matter gets squeezed into the small space under it, trapping the light of the dead star. The gravity is so strong due to the matter being squeezed into a tiny space. Since no light can get out, people can’t see black holes. They are invisible.

Two main classes of black holes have been extensively observed. Stellar-mass black holes with three to dozens of times the Sun’s mass are spread throughout our Milky Way galaxy, while supermassive monsters weighing 1,00,000 to billions of solar masses are found in the centres of most big galaxies, including ours.