active region

The Sun breathes, and that breath has a magnetic rhythm. Every 27 days, the visible surface of the star makes a full rotation, and with it, its magnetic field, like an invisible ribbon wrapped around the star.

The solar corona lives its own turbulent life. Magnetic fields here are governed by the motions of the dense surface — the Sun's photosphere — but occasionally they rewrite the magnetic pattern themselves.

The Sun is constantly struck by blows — magnetic reconnection in the plasma releases energy, making the corona flare up. After each such blow, magnetohydrodynamic waves linger in the plasma loops, like the fading ring of a bell.

The Sun continuously scribbles magnetic fields across its surface. These patterns are not mere ripples but a handwriting in which nature has encoded warnings of flares. A flare is an explosion that releases the energy of billions of nuclear bombs in minutes, ejecting streams of plasma and radiation into space.

Active galactic nuclei (AGN) are the universe’s powerhouses: their X-ray coronae blaze millions of times hotter than stellar atmospheres. But what strikes the spark? A ten-day X-ray campaign by the XRISM and XMM-Newton satellites, aimed at NGC 3783, provided the answer: it’s actual thunderstorms.

Solar flares are powerful explosions on the Sun that can knock out satellites and blackout cities. Predicting them is complicated by the tangled magnetic fields in sunspots.

A sunspot cools, and above it a dark filament, a prominence, hangs for weeks. Inside it, like a compressed spring, hides the magnetic field. It can be laid out in neat arches, or it can be twisted into a tight rope.

The Sun is a boiling cauldron of hydrogen and helium, where scorching gas is caught in magnetic snares. When invisible ropes reconnect, energy comparable to billions of thermonuclear explosions is released. Where does it go?

Light passing by a black hole falls into a gravitational trap: its trajectory curves and the particle bounces along a nearly closed orbit, like a pinball.

In December 2011, Comet Lovejoy boldly raced through the searing corona of the Sun. Right after — a flare. Scientists checked whether the comet could have caused it. The atmosphere of the Sun is threaded with taut magnetic loops, like a drawn bowstring.

The ionosphere at an altitude of 70 kilometers acts like a giant mirror for radio waves. Ground antennas constantly beam signals into it and listen for the reflection. When a solar flare occurs on the Sun, a stream of X-rays reaches Earth in 8 minutes and compresses the lower layer of the ionosphere.

The Sun has regions that resemble an overheated boiler: magnetic fields there twist into tight ropes and store energy. Every so often, a rope snaps, and a flare erupts, a powerful explosion that hurls streams of charged particles into space. Such blasts can knock out satellites and disrupt communications on Earth.

A solar flare is like a giant rubber band that's been twisted and let go. Magnetic field lines on the Sun tangle, snap, and reconnect — a process called magnetic reconnection. At the break point, energy bursts out: particles accelerate, plasma heats up, and we see bright ribbons on the surface.

A cell about to divide first marks its waist. Beneath its membrane, in a thin gel of protein filaments, movement begins. The filaments flow like a slow river, and a belt forms in the middle of the cell. This belt tightens more and more until the cell is pinched in half. Scientists built a computer model of this process.

Neutron stars are the compressed cores of dead stars — city-sized objects with staggering density. Some of these stars become pulsars, cosmic lighthouses emitting strictly periodic radiation pulses.

The Sun sometimes produces giant clouds of plasma that try to escape into space. But often they fail: an invisible magnetic cage keeps them near the surface. Such failed eruptions are called "trapped." Scientists built a computer model to understand exactly how this cage works.

Scientists search for planets around distant stars by detecting a slight wobble in the star's motion: the planet tugs on the star, making its light shift slightly toward the blue and then toward the red. But stars have their own ripples — dark spots and bright faculae on their surfaces. These also shift the light, making it hard to tell them apart from a planet.

The Sun's surface is dotted with dark spots — regions of extremely strong magnetic fields that restrain the boiling of hot gas. From time to time, shock waves race through a spot's atmosphere, like a gust of wind compressing the air ahead of it. The gas briefly flares brightly, and astronomers call these events umbral flashes.

A neutron star the size of a city spins thirty times per second. Its magnetic field is trillions of times stronger than Earth's. Such conditions could spawn a cloud of axions around the star — light particles that no detector has caught yet, but which neatly explain the hidden mass of the Universe.

The Sun is not a calm sphere. Waves constantly ripple through its interior, like a bell after being struck. These oscillations reach the surface and reveal what's happening on the far, invisible side. Astronomers have long been able to 'listen' to this ringing and find large sunspot groups there.

The Sun constantly emits a stream of charged particles — the solar wind. Among them are many electrons, some of which fly back toward the Sun. But observations show that fewer electrons return than expected.

A solar flare is like a giant spring that gets twisted and twisted, and then suddenly snaps. The energy stored in the magnetic field is unleashed into space within minutes, heating plasma to millions of degrees.

A solar flare is like thunder on a clear day: a short but powerful burst of energy. The MeerKAT radio telescope in South Africa caught one such M1.3-class flare and examined it with unprecedented clarity. Ordinary instruments see either bright details or faint ones, but not both at once.

A solar flare is like a tightly coiled spring suddenly uncoiling. In the Sun's corona, energy accumulates in the twisted magnetic field, and then it is abruptly released, accelerating particles and heating plasma.

The Sun frequently launches narrow plasma jets, coronal jets, that resemble fountains of superheated gas erupting from the star's atmosphere. One such eruption, which occurred on November 10, 2022, caught scientists' attention: it was accompanied by a C1.1-class flare and had an unusually wide cone.

A solar flare is like an explosion in the atmosphere: bright, fast, with different 'voices.' X-rays come from electrons that have been accelerated and then abruptly slowed down, losing energy. But in 2017, detectors on the Fermi satellite caught a different signal — gamma rays that didn't fit this picture.

On October 1, 2024, a class X7.1 flare erupted on the Sun — one of the most powerful. Two spacecraft, HXI and STIX, watched it from different angles, like two eyes, and together with a computer model helped reconstruct the three-dimensional picture.

Two stars orbit so closely that their outer layers merge into a shared envelope. Matter flows from one to the other, like water spilling from an overfull cup into its neighbor. In this cosmic dance, where stars literally touch each other, astronomers have for the first time detected magnetic fields in large numbers.

The Sun doesn't rotate as a solid body: its equator spins faster than its poles. This difference in rotation speed creates layers that move at different speeds, like ocean currents at different depths.

The Sun is not just a ball — it's a magnetic mansion. Its invisible force lines, like electrical wiring, thread through space and control space weather. But until now, we've only seen this wiring from the landing — the plane of Earth's orbit. The attic and basement, the magnetic poles, remained a mystery.