Released in 2024, the polarized image of Sagittarius A* shows that the supermassive black hole at the center of the Milky Way exhibits powerful, spiraling magnetic fields.

The first image of Sagittarius A*—the supermassive black hole at the center of the Milky Way Galaxy—was revealed in 2022, almost 50 years after its discovery.

Invisible to direct observation, scientists determined the object at the center of the Milky Way—Sagittarius A*—was a supermassive black hole based on the orbits of fast-moving stars in the area.

The first image of a black hole was created from an international telescope network

The Event Horizon Telescope united radio observatories worldwide to image the supermassive black hole at the center of the Milky Way, known as Sagittarius A*. The team couldn’t transmit their massive dataset online, so they physically flew hundreds of terabytes of data to MIT aboard airplanes.

More than 40 quintillion black holes are estimated to exist in the universe, including about 100 million in the Milky Way, each with masses up to hundreds of times that of the sun.

The first-ever image of a black hole

The Black Hole at the center of galaxy M87 is ready for its close-up, becoming the first black hole to have its image directly captured. The Event Horizon Telescope caught the distant yet massive object—it's more than 55 million light years away—recording its gravity's effect on nearby hot gases.

Black holes can disrupt the formation of galaxies

A team of astronomers in Munich detected a gas cloud being stretched and torn apart by the supermassive black hole at the center of the Milky Way, preventing matter from coalescing into new stars. Energy released from siphoned gas produced warm winds that may also prevent surrounding gas from coalescing.

Black holes 101

At the center of our galaxy, a supermassive black hole churns. Learn about the types of black holes, how they form, and how scientists discovered these invisible, yet extraordinary objects in our universe. This three-minute video from National Geographic tutors the viewer on the basics regarding the universe's most mysterious residents.

Explaining the galaxy-sized gas bubbles hovering around the Milky Way

Depth perception is hard to achieve when looking out into space. For decades, two camps of astrophysicists have disagreed over the nature of the North Polar Spur, a radio-wave emitting arc above the Milky Way galaxy's plane. Was it close and relatively small? Or was it faraway and much more massive? New research utilizing X-ray mapping of the galaxy has helped clarify the existence of both so-called smaller Fermi bubbles and larger X-ray ones.

Research suggests that about 1% of all matter in the universe is locked inside black holes, millions of which are likely to lurk undetected near us in space.

Black holes are formed from massive stars collapsing under their own gravity

This creates a region where spacetime curves infinitely, known as a singularity. Black holes' intense mass and energy allow them to trap light, distort time and space, and present challenges with reconciling Einstein's theory with quantum mechanics.

New model replaces the Milky Way's central black hole with dark matter

A study published in Monthly Notices of the Royal Astronomical Society states that a dense core of fermionic dark matter, rather than a supermassive black hole, could explain both the rapid orbits of stars near the Milky Way's center and the galaxy's large-scale rotation detected in Gaia mission data.

Black holes do not 'suck' matter and energy in like a vacuum cleaner

Despite its immense magnitude, the force of gravity exerted by black holes acts in the same way as provided by stars and planets, allowing objects to maintain stable orbits around them. Even in cases where tidal forces and friction cause objects to change their orbit and fall towards a black hole, they are more likely to glance by, be whipped around, and get ejected rather than absorbed.

Massive objects can significantly bend light to produce gravitational lensing

The theory of general relativity posits that mass and energy bend space and slow down the passage of time. One consequence is that massive objects, such as black holes, curve spacetime to such an extent that light from background sources can loop around them, producing multiple images or ring-like patterns.

Attempts to 'fix' black hole physics have led scientists to theorize new types

Along with their spin and charge, mass is used to categorize black holes as supermassive, intermediate, or stellar-mass. However, ongoing research suggests various additional types may exist, including primordials that formed one second into the universe's birth, fuzzballs—tangles of vibrating strings—and gravastars, which have a shell of dense matter around repulsive vacuum energy.

Nearly 50 years before the first observational evidence, a soldier fighting on the Eastern Front in World War I found a mathematical solution to Einstein's equations that suggested the existence of black holes.

NASA captures image of ghostly cosmic hand

NASA's X-ray space telescopes, Chandra and the Imaging X-ray Polarimetry Explorer, have joined forces to study a hand-shaped structure in space, revealing the magnetic field "bones" of a pulsar wind nebula. Pulsars are rotating neutron stars with strong magnetic fields, creating extreme physics conditions. The combined data from these telescopes provide insight into how pulsars inject particles into space and shape their environment, with the magnetic field playing a crucial role.

Neutron star types, categorized by the presence of strong magnetic fields and radiation beams

Magnetars have magnetic fields about 1,000 times stronger than the average neutron star—roughly a trillion times stronger than Earth's. Pulsars emit beams of radiation from their magnetic poles, which appear as flickering radio wave signals as the object spins.

Mapping the universe's 1.3 million quasars

Quasars form the core of active galaxies where supermassive black holes devour unimaginable amounts of matter. You can see a map of all 1.3 million of these objects with this 3D map. It was assembled with data from the Gaia spacecraft and shows how the spread of dark matter across space matches that described by the Cosmic Microwave Background.

What lies inside a black hole remains one of the universe's greatest mysteries

At the center of black holes is a theoretical point of infinite density called a singularity. Alternatively, one theory suggests a black hole's core could form a Planck star—a mind-bogglingly tiny object just a trillionth trillionth trillionth of a meter in size.

Quasars are extremely luminous cores of distant galaxies, powered by supermassive black holes that consume as much as 100 Earth masses of gas and dust per minute.

Explaining pulsars, the cosmic clocks and lighthouses of the universe

As of 2023, over 3,000 of these rapidly rotating neutron stars have been discovered, which contain magnetic fields along which energized particles accelerate and emit light, including X-rays, gamma rays, visible light, and, most commonly, radio waves. The fastest of these, PSR J1748–2446ad, rotates 716 times per second, meaning its surface equator moves at about 24% the speed of light.

The edge of the Milky Way may be identified by its star-forming disk

Like Earth's atmosphere and its core, galaxies become more diffuse with increasing distance from their centers, making it hard to define where they end. However, one approach focuses on where gas concentrations are no longer dense enough to support measurable star formation.

The trajectory of particles in bubble chambers reveals their properties

The presence of magnetic fields produces spiraling paths in charged particles as they move across the field, with faster and more massive particles moving in wider turns. Gaps in the trails indicate the presence of short-lived particles that are undetectable until they decay.

Mars' orbit may provide evidence that dark matter is made of primordial black holes

Physicists at MIT have found that, statistically, one such microscopic black hole should pass through the solar system every decade, which they predict would introduce a detectable wobble in Mars' orbit. Such black holes would have formed in the early universe from collapsing gas clouds and scattered as the universe expanded.

TON 618, the largest black hole ever detected, has the mass of 66 billion suns

The supermassive black hole is 18 billion light-years away and emits radiation with the brightness of 100 trillion stars. It is so massive that light would take an entire week to travel from its edge to its center.

Differential rotation and density waves create the arms of spiral galaxies

Stars and gas near the galaxy's center complete an orbit in less time than objects farther out. Pressure waves cause material to bunch, lagging behind stars and gas that orbit closer to the center and forming the arms.

Watch a simulation of a collapsing star becoming a black hole

When a massive star can no longer release enough energy through fusion in its core to fight off gravitational collapse, the dense core collapses first, producing an event horizon that traps light within it, including some light produced within the star at the time of collapse. As more material falls into the growing event horizon, the star will appear to eclipse itself from the inside.

When they merge, black holes release multiple solar masses of energy

The energy emanates outward in the form of gravitational waves, which can be detected at observatories like LIGO. After merging, it is impossible to determine the characteristics of the two black holes that merged to create it.

Cygnus X-1 helped scientists confirm black holes are real and measurable phenomena

The 1964 discovery of Cygnus X-1 provided the first strong candidate, but it took decades—and a famous bet between Stephen Hawking and Kip Thorne—before scientists were certain it was a black hole. Hawking's thumbprinted concession was delivered after breaking into Thorne's office.

The structure of the Bullet Cluster—a collision between two clusters of galaxies—cannot be explained without dark matter, and serves as evidence for the existence of the invisible substance.

The mysterious origins of the universe’s biggest black holes

Think you know everything about black holes? You might be surprised. Thought of as massive vacuum cleaners sucking up everything in their cosmic path, black holes actually accrete matter at an incredibly slow pace. Yet, some black holes existed when the universe was only a few billion years young. Learn more in this BBC report.