A team of North American astronomers have discovered the two largest supermassive black holes yet found — each a nearly unfathomable 10 billion times the mass of Earth’s Sun — the Gemini Observatory announced on Monday.
“We see them only because of their gravitational pull on nearby orbiting stars,” said team leaer Chung-Pei Ma, an astronomy professor at the University of California, Berkeley, in a release from the Gemini Observatory.
“These black holes may shed light on how black holes and their surrounding galaxies have nurtured each other since the early universe,” said University of California, Berkeley grad student Nicholas McConnell, the first author of a paper on the find that will be published in the December 8 edition of the journal Nature, according to a
The new largest supermassive black holes are thought to be the similar to those that powered quasars, the most distant, brightest and among the most mysterious objects from the early days of the universe.
Both black holes were discovered using the Gemini North telescope on Mauna Kea, Hawaii.
One clocks in at an estimated 9.7 billion “solar masses” and was found in the elliptical galaxy NGC 3842, located 320 million light years from Earth in the Leo galaxy cluster, the University of Michigan reported. See a hi-res illustration of the size of that black hole here.
The second supermassive black hole might be even larger, up to 21 billion times the mass of Earth’s sun, the New York Times reported, and was found in the elliptical galaxy NGC 4889, located 336 million light years away from Earth in the Coma cluster.
Both galaxies are part of the Coma supercluster and can be viewed with amateur telescopes, the Gemini Observatory reported.
For comparison, one solar mass, the size of Earth’s Sun, is roughly equivalent to 330,000 times the mass of the Earth.
Moreover, the event horizons for the black holes — the region at which no light is able to escape getting sucked into the black holes — are far larger than the entirety of our Solar System, with each event horizon extending five to ten times as large as Pluto’s orbit.
“This means we need exquisite observing conditions and the latest technology to have any hope of seeing what’s going on around the black hole,” McConnell said in the Gemini release.
Supermassive black holes are those millions or billions of times the mass of Earth’s sun. Previously, the largest known was found at the center of the galaxy M87, measuring 6.6 billion solar masses, also measured using the Gemini North telescope.
All large galaxies are thought to have a supermassive black hole at the center, including our own, the Milky Way. That black hole, Sagittarius A Star, is thought to be at least 2.6 million solar masses and up to 4 million solar masses.
And many more questions have been sparked by the finding of the new black holes, chief among them: How did they get so large? Either due to sucking up stellar gas, which they are no longer doing, or from the merging of two galaxies into one larger galaxy.
“For an astronomer, finding these insatiable black holes is like finally encountering people nine feet tall, whose great height had only been inferred from fossilized bones. How did they grow so large?” Ma said. “This rare find will help us understand whether these black holes had very tall parents or ate a lot of spinach.”
Also, are these two black holes rare giants or just the first of a whole crowd of previously unknown supermassive black holes?
Those answers are still floating out there in space.
The team’s research was funded by the National Science Foundation, the National Aeronautics and Space Administration, and UC Berkeley’s Miller Institute for Basic Research in Science.