chandra

A spotlight beam cuts through the night fog. Part of the light we see comes directly from the lamp, and part from water droplets that scatter that light.

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.

At the heart of the giant galaxy Hydra-A, there's a hive of activity. A supermassive black hole shoots out two powerful plasma jets. They punch through the surrounding cloud of hot gas and inflate giant bubbles within it.

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.

A massive star doesn’t simply fade away — it blows up as a supernova, leaving behind an expanding remnant and a wildly spinning neutron star — a pulsar. In this cosmic storm, astonishing patterns emerge, and the 'Nimbus'–'Thunder' system is a dazzling illustration.

Dark matter detectors are essentially incredibly sensitive microphones, capable of hearing a whisper amid the roar of a rock concert. Their job is to catch the rare nudges from hypothetical dark matter particles, which are thought to occasionally collide with atomic nuclei of ordinary matter.

When a massive star dies, its core collapses, and a supernova explosion occurs. The cataclysm births streams of particles — like ripples from a thrown stone. The first to arrive are swift neutrinos, which pierce the Earth, hardly interacting. Then, hours later, ghost particles with a tiny charge appear.

Tiny invisible bullets pass straight through the Sun, barely noticing its matter. These are axions — hypothetical particles so light and elusive that they are often compared to ghosts.

A giant cauldron that barely smolders most of the time, but occasionally spits out showers of sparks. That is roughly how the supermassive black hole at the center of our galaxy — Sagittarius A*—behaves. It weighs four million times as much as the Sun and lies 26,000 light-years away.

The solar wind, a stream of charged particles from the Sun, slams into the tenuous gas that fills the space between the stars. The collision produces a faint X-ray glow. For astronomers, this is like fog in front of headlights: it obscures distant objects.

In 1987, astronomers saw a supernova flare up in a neighboring galaxy — the Large Magellanic Cloud. It was a rare gift: the explosion was close enough to catch not just light but also neutrinos, those nearly undetectable particles that pass straight through Earth.

The center of our galaxy is a crowded kitchen where several dishes are simmering at once, and their steam blends into a single cloud. X-rays from the exploded star's remnant, from the stellar wind around the supermassive black hole, and from hot gas between stars all overlap.

When a massive star dies, a supernova explosion occurs, so powerful that a single flash outshines an entire galaxy. In this fire, billions of axions are born — invisible particles that leave almost no trace. Every second, trillions of these tiny things fly right through each of us, completely unnoticed.

For half a century, astronomers puzzled over the nature of the powerful X-ray emission from Gamma Cassiopeiae — a bright beacon in its constellation whose X-ray glow didn't fit models of single stars. An invisible companion was suspected, but direct evidence was lacking.

At the center of the Milky Way, among dense clouds of gas and dust, lies a region called Sagittarius C. It's like a bustling crossroads: stars are born here, streams of matter collide, and the whole scene is illuminated by X-rays. For a long time, this glow remained a mystery.

The night sky is full of beacons, but some shine in a way that makes them nearly invisible. Astronomers have discovered a new class of objects: ultrasoft X-ray sources. They are so "cool" by X-ray standards that their emission falls at the boundary between ultraviolet and soft X-rays, where ordinary telescopes are almost blind.

Cosmic particles with energies millions of times greater than anything our accelerators can produce slam into the atmosphere and create a shower of secondary particles. This shower emits radio waves that antennas on the ground pick up. But the signal is weak: it's swamped by the radio noise of our galaxy and the receivers' own noise.

When an X-ray burst erupts on a neutron star, its atmosphere heats up to millions of degrees. The light we catch with telescopes passes through this dense layer of gas, and gets dramatically altered along the way. The spectrum no longer looks like that of an ideal radiator: some colors get amplified, others dim.

For years, an X-ray telescope in orbit recorded how binary systems shine, where an ordinary star orbits a black hole or a neutron star. Matter from the companion falls onto the compact object, heats up to millions of degrees, and emits X-rays.

When a massive star runs out of fuel, it collapses and explodes as a supernova. An instant before the catastrophe, neutrinos — ghostly particles — burst from the core. They rush through the star and interstellar space like the smell of smoke, heralding a fire that will only ignite minutes or even days later.

Twenty years ago, an X-ray image of the Arches cluster resembled a photo of a person in thick fog: the cluster itself was drowned in the glow of a neighboring cloud. The cloud acted like a mirror, reflecting hard radiation from the vicinity of the black hole, and that reflection swamped the faint signal from the stars.

As it travels through the Galaxy, the Solar System occasionally dives into thick interstellar clouds — clumps of tenuous hydrogen and dust.

An X-ray telescope points at a neighboring galaxy, and sees a point that wasn't there yesterday. A month later, it blazes hundreds of times brighter than the Sun, and a year after that, it fades again. Such points are called ultraluminous X-ray sources, and each one is a close pair: an ordinary star and a black hole or neutron star, whirling around each other.

A firefly blinks for one ten-billionth of a second somewhere above the Siberian taiga. Seeing such a thing is impossible, but the TAIGA-HiSCORE array, spread across a valley in the Tunkinsky district of Buryatia, tried to catch exactly such flashes — not from insects, but from the depths of space.