The second largest black hole in the Milky Way is discovered! Here's what the researchers say


The second largest black hole in the Milky Way is discovered! Here's what

Astronomers have discovered a black hole with a mass about 33 times that of the sun, the largest found in our galaxy known as the "Milky Way". Another supermassive black hole is at the center of our galaxy.

The newly identified black hole is located about 2,000 light-years from Earth, relatively close in cosmic terms, in the constellation Aquila and has a companion star orbiting it, researchers said Tuesday. A light year is the distance that light travels in one year, about 9.5 trillion km.

Black holes are part of the space in the universe where gravity is so strong that even light cannot escape, which makes them difficult to detect.

This black hole was identified through observations made by the European Space Agency's Gaia mission, as it caused the wobble of its companion star. The Gaia mission is compiling a major inventory of stars.

Data from the Chile-based European Southern Observatory's Very Large Telescope and other ground-based observatories were used to verify the black hole's mass.

"This black hole is not only very massive, but also very special in many ways. It's actually something we never expected to discover," says Pasquale Panuzzo, a research engineer at the French research agency CNRS, who works at the Paris Observatory. He is the main author of the study published in the journal "Astronomy & Astrophysics".

One of the features is that the black hole, called Gaia BH3, and its companion star are traveling within the galaxy in the opposite direction to the way stars normally travel in their orbits in the Milky Way.

Gaia BH3 probably formed after the breakup of a star that was about 40 times more massive than the sun, the researchers said.

Black holes that form from the disintegration of a single star are called stellar black holes. Gaia BH3 is the largest stellar black hole known so far, according to astronomer and study co-author Tsevi Mazeh of Tel Aviv University in Israel.

When the star in question exploded at the end of its lifespan, a phenomenon known as a supernova, some of the constituent materials were scattered into space, while the rest exploded violently to create the black hole. The universe is thought to be 13.7 billion years old.

The black hole's companion star, Gaia BH3, is as old as the other star that exploded and is about 76% the mass of the sun and slightly cooler, but has a luminosity about 10 times higher.

The star revolves around the black hole in an elliptical orbit at a distance of about 4.5 times that between the Earth and the Sun, a measurement called an astronomical unit, abbreviated AU and 29AU. By comparison, Jupiter orbits about five AU from the sun and Neptune about 30 AU.

"The surprising discovery for me was the fact that the chemical composition of this companion star does not show anything special, so it was not affected by the black hole supernova explosion," said astronomer and study co-author Elisabetta Caffau, who works with the Observatory of Paris.

Scientists aren't sure how big stellar black holes can be. "The maximum mass of a stellar black hole is a matter of active scientific debate," said scientist Panuzzo./VOA