Astronomers say they may have solved the decades-old mystery of why some galaxies stop creating stars, causing them to die.
From imaging black holes, rovers on Mars, chimeric embryos, and coming up with solutions to plastic pollution, 2021 has been an important year for science.
The discovery by astronomers could help us better understand how some black holes grow to such tremendous sizes.
"The flash was so powerful that it lit up the stream like a Christmas tree," said researcher Andrew Fox.
"Imagine condensing two-thirds of the Milky Way—which has a stellar mass equivalent to 60 billion suns—into a black hole and you have what we measured," said researcher Roberto Saglia.
"Up until now, such a concentration of three supermassive black holes had never been discovered in the universe," Peter Weilbacher, from the Leibniz Institute for Astrophysics Potsdam, said.
Black holes are dead stars that, after exploding as supernovae, have so much mass that nothing can hold them together, causing them to collapse into a singularity.
"Simulations and movies like these really help us visualize what Einstein meant when he said that gravity warps the fabric of space and time," the creator of the images said.
The star, named J0740+6620, has a mass more than two times that of our sun, but is just 18 miles wide.
Astronomers found a "runaway star," dubbed PG 1610+062, in the outer halo of the Milky Way.
The findings expand our knowledge of black holes and the galaxies within which they are often found.
Astronomers have spotted a black hole spewing out vast amounts of incredibly cold gas.
Scientists think that at the heart of nearly every galaxy lies a supermassive black hole (SMBH) with immense gravity.
The galaxy belongs to a recently discovered, rare and unusual class of stellar systems known as ultracompact dwarfs.
The image reveals in incredible detail a fiery region surrounding the supermassive black hole that lies at the heart of the Milky Way.
"It was surprising, but you like to be surprised in science."
The event horizon is the point of no return beyond which nothing, not even light, can escape the immense gravitational pull of the black hole.
The black holes surround the supermassive black hole at the center of the Milky Way.
The planets face supernovas, gamma-ray bursts and gravity-disrupting stars in the crowded center of the Milky Way.
They'e even predicting where the event is most likely to occur.
How supermassive black holes formed so quickly after the start of the universe has long baffled scientists.