Paris - (AFP) - Scientists have succeeded in observing a very rare phenomenon that occurred 8.5 billion light-years away from planet Earth , in which a huge black hole appears to devour a star, then spits out the waste of its "meal" in the form of a luminous stream.

The black hole has a gravitational attraction that causes any star that approaches it to be torn apart, as the material that the star is made of disintegrates, then it rotates very quickly around the black hole before it swallows part of it forever.

This phenomenon called "tidal rupture" is rarely accompanied by the emission of a particle-based light flux, which comes from the star's matter and is transient and travels at a speed close to light.

Two studies published this week in the journals Nature and Nature Astronomy say the last time an event of this kind was observed was in 2012.

Since then, new monitoring methods have been invented, including a large-capacity camera installed at the Palomar Observatory in California, which allows “a survey of the sky,” Susana Fergani, a researcher affiliated with the National Center for Scientific Research at the Paris-PSL Observatory, told AFP.
The astrophysicist who participated in the research explained that this telescope, known as the wicky Transient Facility, "monitors every night dozens of bright streams in the sky and can choose the most prominent of them."

Indeed, one of these outbursts seemed out of the ordinary, as it was neither a supernova (an explosion of a star at the end of its life that produces unusual luminosity), nor was it a gamma-ray burst (the most powerful source of light in the universe).

And in an effort to provide a clearer view, a number of multinational astronomers have coordinated among themselves to arm instruments from all over the world to observe the phenomenon on a variety of wavelengths, from X-rays to radio waves.

These include the Northern extended millimeter array (NOEMA) radio telescope in the French Alps, and the spectrograph on the European Southern Observatory (ESO)'s Very Large Telescope in Chile.

Scientists have determined that the light stream originated an estimated 8.5 billion light-years from Earth, around a black hole likely lurking at the center of the host galaxy.

Dubbed AT2022cmc, the jet is "a billion times more powerful than our Sun's X-ray luminosity," said Susanna Fergani. Its duration is very short, 30 days. "The AT2022cmc stream is transient, unlike the jets from active galactic nuclei, which extend on much larger scales," the researcher added. This jet appears to have been caused by the black hole tearing apart the star.

It is unlikely that the jet comes from light swallowed by the black hole, since nothing can escape from these "cosmic goblins", but rather from the accretion disk surrounding the black hole spewing out particles at its ends. Just like a squeezed toothpaste tube, explains the European Observatory.

This phenomenon, which is still not well understood, could be caused by the speed of rotation of the black hole, as it rotates on itself at a speed that allows it to produce this jet. The future Large Synoptic Survey Telescope (LSST) being built in Chile should make it possible to observe other outbursts of this type, and thus better understand the extreme environments surrounding black holes.