Huge explosions recorded in space: what are their causes?

In September 2022, astronomers in Southern California, USA, noticed a bright blue flash of light in space. The light was at least ten billion times stronger than sunlight, and appeared to be coming from a galaxy a billion light-years away. But what is the reason for this unprecedented boom?

Flashes brightly for a short time

“We looked at the pictures and all we could think was: Is this really happening?” says Anna Hu, an astronomer at Cornell University. “We have never seen such a bright flash in space, and never before have we seen such a flash for such a short time.”

The scientific article she and her colleagues published about the phenomenon in a specialized journal nature It resolves a long-standing debate about the nature and origins of these mysterious explosions. Although much remains unclear, the discovery suggests that the flashes of light may be caused by an extremely massive object, such as a black hole or neutron star.

What is this flashing heavenly light?

By pointing a large number of telescopes at the flash of light, the researchers discovered that this phenomenon must be what is called a Luminous Fast Blue Optical Transient (LFBOT): a fast, bright burst of light that occurs mainly in the blue part of the galaxy. The electromagnetic spectrum, more of which has been observed in recent years. Three months after the new LFBOT was turned off, astronomers noticed another flash of light of the same brightness.

But what exactly the researchers saw remains a mystery. It is possible that the flashes are caused by bright light emanating from the source, such as the light from a lighthouse that travels across the ground as the lighthouse light rotates. The explosions could also be due to the irregular magnetic fields of a young neutron star. Or perhaps differences in the so-called accretion disk around a black hole: a disk around a celestial body in which material accumulates and can emit X-rays.

“We still don't know exactly what it is,” Ho says. “But the more we learn about LFBOT learning, the closer we get to the answer.”