Scientist discover the two biggest ever observed black holes.

"They were found in the heart of two giant galaxies . They have a mass more than 10 billion times greater than the Sun and are located more than 300 million light years."

The two most massive black holes that were found so far were found in the heart of two giant galaxies, located at several hundred million kilometers from Earth, according to a study published Monday.

Black holes have a mass more than 10 billion times greater than the Sun, a record, the article published in the journal Nature.

So far, the largest known black hole has a mass of 6,300 million solar masses and belongs to the giant elliptical galaxy Messier 87, one of the largest among them are close to ours, the Milky Way.

Nicholas McConnell's team and Chung-Pei Ma, University of California, Berkeley, discovered the massive black holes after the measurement data from two nearby galaxies, reveals research.

They were found in the galaxy NGC 3842, located more than 310 million light years, NGC 4889 and to 330 million light years, and are much larger than expected U.S. researchers have discovered them, he said.

The galaxy NGC 3842 has a central black hole with a mass of 9,700 million solar masses and NGC 4889 has a black hole with a mass comparable or larger.