At the center of the Milky Way galaxy, nearly 26,000 light-years away, a cluster of stars circles close to the supermassive black hole known as Sagittarius A*. As these few dozen stars, called S-stars, approach the black hole—which is about four million times more massive than the sun—its immense gravitational force whips them around faster than 16 million miles per hour. In fact, the gravitational pull of Sagittarius A* is so intense that it warps the light from these stars when they stray too close, stretching the wavelengths toward the red part of the electromagnetic spectrum. Continue reading A Star Orbiting in the Extreme Gravity of a Black Hole Validates General Relativity
Less than two weeks after the gravitational wave detectors turned back on, they’ve already seen evidence of two pairs of colliding black holes. Continue reading Gravitational Wave Detectors Spot Two Potential Black Hole Collisions in a Week
At the center of a galaxy called Messier 87, about 55 million light-years away, about which all of the matter of the galaxy orbits, there lies a monster: a supermassive black hole. With about 6.5 billion times the mass of the sun, the black hole at the center of M87 is so dense that its escape velocity, or the velocity needed to escape the object’s gravity, is more than the speed of light. Accordingly, not even photons of light can escape once they wander too close.
Just months after discovering FarOut, the most distant known object in the Solar System, the same team of astronomers has detected the faint—but not yet confirmed—glimmerings of an object even farther away. Dubbed FarFarOut, the extreme dwarf planet is 13 billion miles away—a distance so far it takes nearly 20 hours for the Sun’s rays to reach it. Continue reading Extreme Dwarf Planet FarFarOut Could Be the Most Distant Known Object in the Solar System
Scientists are dreaming up ways to probe the nature of the Universe’s smallest bits—quarks—by observing ultra-dense neutron stars slamming into each other. Continue reading Neutron Star Collisions Could Reveal Mysterious Quark Matter
While inspecting a known globular cluster, a team of astronomers began to notice that some of its stars didn’t seem to belong. Investigating further, they realized the anomalous stars were part of a nearby galaxy—one previously unknown to us.
Science works in mysterious ways. Continue reading Astronomers Accidentally Discover a Hidden Galaxy Right Next Door
New research suggests that much of the material that made life possible on Earth arrived after a cataclysmic collision between our planet and a Mars-sized object billions of years ago—likely the same collision that produced the Moon, the scientists say. Continue reading A Collision With Another Planet May Have Seeded Earth With the Ingredients for Life