black hole accretion

At the center of an ultra-compact dwarf galaxy, a very dense stellar system spanning tens of light-years, there is a vacuum cleaner at work. But instead of dust, it sucks in gas shed by dying stars. This gas does not fly off in all directions; instead, it spirals into a funnel, a rotating disk that gradually settles onto the black hole.

A black hole paired with a star works like a pump: it pulls gas from its companion, swirls it into a glowing disk, and occasionally ejects some of that matter in two narrow jets. In 2021, the system 4U 1543-475 put on such a show.

In the furnace of star formation, the heat reaches 900 degrees Celsius, like a glowing blast furnace. It is in this hellish heat that cosmic crystals are born. Astronomers have for the first time caught the moment when crystalline dust appears right during an accretion flare (when the star gobbles up surrounding gas) at the very young star EC 53, still cocooned in dense gas.

May 2022. The space polarimeter IXPE, the spectroscope NuSTAR, and the monitor NICER simultaneously stared at one spot in the sky — at the black hole in the Cygnus X-1 system, where it orbits a blue supergiant in a close binary system with a period of 5.6 days.

A marathon lasting 13 billion years started with different weights. A hundred solar masses — lighter than some gas clouds. A hundred thousand — gravitational dominance, comparable to an elephant among kittens. That's what black hole seeds looked like, ones that by our time should have turned into supermassive giants.

A black hole is a place from which nothing can escape. But some theories allow that deep inside, at the quantum level, it might bounce and turn into its opposite — a white hole, which only spews out matter and light. A group of physicists built a computer model of such a transformation.

Water turns to ice at zero degrees — sharply, with no intermediate states. Something similar happens to complexity when we take a random quantum state of an entire system and look only at a part of it. As long as that part occupies less than half the system, its complexity grows smoothly. But as soon as the fraction crosses 50%, a jump occurs.

A swarm of tiny invisible particles, like a cloud of pollen, drifts through space. A black hole sits in its path. Some particles fall in and vanish forever; others swing around the trap and fly away. The physicists built a map showing exactly how much matter gets swallowed and how much survives.

Ten billion years ago, the universe was speckled with strange crimson sparks. The JWST spotted them in images at distant redshifts — compact sources blazing like entire galaxies yet no larger than a tiny central region. Astronomers nicknamed them “little red dots.” Their nature long defied explanation.

The early universe at redshift z>7 was an arena of rampant growth: black holes with masses up to a billion solar masses already blazed as quasars, devouring gas at monstrous rates. How these giants managed to grow in such a short time is one of astrophysics' sharpest puzzles.

A black hole is not a frozen void, but a living magnetic engine. Its 'heart'—the accretion disk, pulsates: inhale, matter spirals into the funnel, exhale — magnetic reconnection tears the field lines, and plasma shoots away from the horizon.

The heart of many galaxies is a supermassive black hole. It doesn't just sit at the center; it occasionally flares brightly as it swallows surrounding gas.

The James Webb Space Telescope has spotted astonishing objects in the depths of space — tiny red dots that shine so brightly it's as if a spotlight were hidden inside a small bulb. These dots are not stars or galaxies in the usual sense, but rather 'cocoons' around supermassive black holes greedily gulping down surrounding gas.

Water plunges into an abyss, but part of it shoots back up — churning and foaming at the very edge. That's roughly how gas behaves as it flows onto a supermassive black hole when its stream becomes too dense. In a new study, scientists traced this picture using computer simulations.

A powerful vacuum cleaner sucks in not only dust but also its own collection bag. That's roughly how a black hole behaves at the center of a 'red dot'—a distant galaxy where the glow comes not from the hole itself but from its dense gas shroud. This shroud is so thick it resembles a puffed-up cool star. And, like many stars, it has a magnetic field.

A sponge thrown into a bucket of water eagerly soaks up moisture and swells before your eyes. But if you keep adding water and squeeze and release the sponge, absorption becomes harder and takes longer. That's roughly how tiny black holes behaved at the very beginning of the universe.

A lantern shines through thick fog. Light scatters off water droplets, and the lantern appears blurred. Something similar happens around a black hole: hot gas, like fog, envelops it, while X-rays from the inner parts of the disk struggle through this cloud. Only here, the "droplets" are electrons, and the "fog" itself is called the corona.

A black hole is not just a dark sphere in space. If there is gas and dust nearby, they swirl into a flat, glowing disk that gradually falls inward. This disk acts like a lamp, illuminating the hole itself, and against the bright background you can see its shadow — a dark silhouette with sharp edges. But what if the disk is not flat but torn into pieces?

A bottomless well, but not quite. An ordinary black hole has a boundary, the event horizon, beyond which nothing returns. But what if you remove that boundary? That's exactly the kind of object, dubbed JMN-1, that astrophysicists modeled: a massive body born from stellar collapse, but without the impenetrable veil.

The night sky looks still, but sometimes one of the stars suddenly begins to brighten. That's what happened with the system AT 2019wey: it was spotted by the TESS telescope, which usually hunts for planets around other stars, but happened to be imaging that patch of sky every half hour.

In its youth, Earth resembled a beehive: it grew by sticking together from countless rocky chunks. When the main construction was over, a late swarm of meteorites rained down on the young planet — the so-called late veneer. These impacts, scientists thought, brought platinum, gold, and other rare metals to Earth's upper layers.

During its 2021 outburst, the black hole in the GX 339-4 system behaved like an actress changing costumes between scenes. In the hard state, it wore two coronas at once: a hot, rarefied one, and over it, a warm, dense one. In the soft state, only the hot corona remained.

In 2026, a black hole in the binary system GS 1354-64 woke up: it began pulling matter from its companion star, and a scorching disk swirled around it.

Not all water in a whirlpool goes down the drain: some splashes back up in narrow sprays. Gas near a black hole behaves similarly. It falls, heats up, collides with itself, and part of it is ejected back into space in two narrow jets that fly in opposite directions.

A black hole is not just the universe's trash can; it is more like a safe with a secret code. For decades, it was thought that any signal sent toward the event horizon would be partially reflected back: curved spacetime acts like a funhouse mirror, and some energy always escapes.

About 25,000 light-years from Earth, in the constellation Sagittarius, a dense veil wraps around the neutron star GX 13+1. It scatters X-ray photons the way fog scatters streetlight, and for a long time it hid the source's true power from astronomers.