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The night sky only looks black: telescopes reveal millions of galaxies, but some are so dim they blend into the background. Astronomers caught just such a "nearly invisible" one by chance while observing the Virgo Cluster with the two-meter telescope at Teide Observatory. The galaxy is named TTT J1237327+143535.

The galaxy cluster RXC J0528.9−3927 is like a city shrouded in fog: at its center, a radio halo shines brightly, but farther out, beyond the usual boundaries, astronomers have spotted a barely visible glow. It stretches for two million light-years — three times farther than the halo itself.

Galaxy NGC 5584 is a vast stellar city, where some neighborhoods are just being built while others are already marked by aging giants. To see both, astronomers used two very different flashlights. The ultraviolet telescope Swift lit up hot blue patches — stellar nurseries where massive stars have recently ignited.

Somewhere in the depths of space, two supermassive black holes are circling each other. Their dance is not smooth — the orbit is stretched, like a rubber band that alternately tightens and relaxes. Each revolution sends ripples through the fabric of spacetime — gravitational waves.

A gravitational wave from a black hole merger is like a bell tolling in the night. The loudness tells you how far away the source is. But to learn how fast the night itself, the cosmos, is expanding, you usually need a second signal: a flash of light or a catalog of galaxies. Both are rare to catch.

In a dark room, a whisper is barely audible. To make out the words, you need to get close, or set up many sensitive microphones. That's roughly the reasoning behind the new work: the authors place quantum "ears" right inside a resonator, where a high-frequency gravitational wave turns into an electromagnetic echo.

A noisy café. You're trying to make out two quiet conversations: one from the table by the window (black hole mergers), the other a barely audible whisper from the far corner (echoes of the universe's birth). But the hiss of the espresso machine and street noise (detector jitter) drown everything out. New work teaches a computer to separate these sounds.

Layer by layer, artifact by artifact — an archaeologist reconstructs the history of an ancient settlement. Similarly, astrophysicists sifting through 259 records from LIGO–Virgo–KAGRA saw a clear layered structure among merging black holes.

On November 23, 2023, LIGO detectors caught something strange. The gravitational wave signal from a black hole merger, designated GW231123, pointed to record masses—137 and 101 solar masses, and anomalously fast spin. That would be the most massive and fastest-spinning pair ever detected.

Space is full of invisible waves — ripples in the fabric of spacetime left behind by cataclysms like black hole mergers. An ordinary black hole swallows everything without a trace. But there are hypothetical exotic objects — ultradense clumps of matter without an event horizon (a surface from which not even light can escape).

A huge bowl of water. Drop a stone into it — ripples spread across the surface. The fabric of spacetime works much the same way: when two massive stars merge, they create ripples — gravitational waves. These waves travel to Earth and are picked up by giant detectors like LIGO and Virgo.

In August 2019, the LIGO and Virgo detectors picked up gravitational waves from the merger of two compact objects in a binary star. One weighed 23 solar masses — a standard black hole. The other came in at 2.5–2.67 M⊙.

A spinning top that makes a hundred turns per second suddenly starts losing speed dramatically — much faster than any known top. That's exactly what pulsar J0435+3233 is doing. It's a dead star, crushed to the size of a city, but whirling at a furious rate.

When two black holes merge far away, we receive a tremor of space — gravitational waves. Usually, they are described by Einstein's equations, but what if gravity works differently at the tiniest distances? The authors took one such hypothesis — Hořava–Lifshitz gravity.

In May 2020, the LIGO and Virgo detectors picked up a gravitational-wave burst known as GW200105. Among the many similar gravitational waves recorded, this one stood out for an oddity: the orbit of the colliding neutron star and black hole was not a perfect circle, but a stretched ellipse.

The Universe is humming, but our ears catch only the bass. LIGO hears the rumble of black hole mergers — the infrasound of space. Higher up, in the gigahertz range, the flutes and violins of primordial gravity ring out.

Gravitational-wave detectors are like sensitive microphones, listening for the whispers of distant cataclysms. But every now and then, a sharp crack bursts in — a brief noise spike known as a glitch.

Two neutron stars spiral closer and collide. The result: a gravitational wave, a ripple in spacetime, a short gamma-ray burst, and a faint glow astronomers call a kilonova. But sometimes the signal passes by a massive galaxy.

A low rumble coming from underground could be the noise of a distant construction site, or it could be the echo of an ancient earthquake. Astronomers faced a similar puzzle in 2023 when they detected ultra-low-frequency gravitational waves — the trembling of spacetime itself, rippling across the universe.

The universe rewrites its history again and again. Where ordinary astronomy sees only a point, a black hole, gravitational waves peel back thin layers of the past, like an ancient palimpsest. The idea that black holes can grow by devouring each other, and their offspring can enter new unions, has been discussed by astrophysicists for half a century.

In the ocean of space, every storm of birth or merger of supermassive black holes generates ripples — gravitational waves traveling at the speed of light. Over billions of years, these waves superimpose, merging into a low-frequency hum, like a distant surf.

The universe speaks in the language of gravitational waves — ripples in the fabric of spacetime itself.

The cosmos sets its own lenses in the path of gravitational waves. When two black holes merge, the resulting ripple travels through the universe. If it encounters a massive galaxy cluster along the way, its gravity bends the path of the waves — much like glass focuses light.

LIGO and Virgo detectors catch ripples in spacetime, but some signals force us to rewrite the scripts of stellar death. GW190814 — the merger of a black hole of 23 solar masses with a compact object of 2.6 solar masses — is a discordant chord in the symphony of standard models.

A gravitational wave observatory is like a set of microphones scattered across the Earth. When a signal arrives from space (say, from a black hole merger or a supernova explosion) each microphone hears something slightly different.

A hum resonates across the universe. It is not sound, but a trembling of space itself — the gravitational wave background. It is produced by pairs of supermassive black holes circling each other at the centers of distant galaxies. Each pair is like a bass instrument in a vast orchestra.

In 2015, detectors caught a gravitational wave for the first time — a ripple in space that traveled from merging black holes. Since then, such signals have become a new window into the universe for astrophysics. But gravitational waves can do more: they carry the imprint of the very theory of gravity.

Waves sort pebbles on a sandy beach. Small stones lie close together, nearly identical in size. Farther from shore, there's a scatter of larger and more varied ones. And right at the waterline, where the surf is strongest, the biggest and most rounded fragments pile up. Nature sorts black holes by mass in much the same way when they merge in pairs.

When a distant galaxy sends us light, it dims with distance, and from that dimming, we can tell how far away it is. Gravitational waves work in much the same way: the farther their source, the weaker the ripple in space that detectors on Earth pick up.

At the heart of nearly every large galaxy lives a supermassive black hole — a silent giant around which stars, gas, and other, smaller black holes orbit. From time to time, one of these objects breaks free from its orbit and begins to fall toward the central monster in a tightening spiral.

At the center of the Milky Way, like a matryoshka doll within a matryoshka doll, lies a supermassive black hole, surrounded by a swarm of stars and an invisible shell of dark matter. This shell, or "spike," is expected to be extremely dense right at the horizon.

Two black holes spiraling toward each other resemble figure skaters in a pair spin: each rotates about its own axis, and together they weave a shared dance. This collective twist, the so-called effective spin, can be measured by astronomers from the gravitational waves rippling outward from the pair, like ripples on a pond.

Gravitational waves are ripples in the very fabric of spacetime, akin to vibrations of a giant cosmic string. Conventional detectors like LIGO and Virgo pick up low-frequency "notes"—disturbances from mergers of massive black holes of stellar masses.

Imagine an orchestra where each musician plays their own part, and the conductor tries to catch a faint rhythm common to all. That's roughly how astronomers search for gravitational waves from pairs of supermassive black holes (weighing billions of suns) circling each other in distant galaxies.

On May 14, 2019, LIGO detectors registered a gravitational burst that didn't fit the usual mold. Event GW190521 appeared as a collision of two black holes weighing 85 and 66 solar masses. The resulting hole of 142 solar masses landed right in the "forbidden" range — where stellar collapses leave almost no trace.

A neutron star is a super-dense remnant of a supernova explosion, where a teaspoon of matter weighs a billion tons. Many of them, as discovered back in 1967 by Jocelyn Bell Burnell, become pulsars — cosmic lighthouses that regularly flash in the radio band.

It was Edwin Hubble who discovered that galaxies are rushing apart, and Georges Lemaître linked this to the expansion of space. Today, the ΛCDM model, relying on dark energy and dark matter, asserts that the Universe is flat as a perfectly stretched canvas.

LIGO, Virgo, and KAGRA detectors act like giant microphones, listening in on gravitational waves — vibrations of space itself. The new GWTC-5.0 catalog recorded 161 black hole mergers, bringing the total count to 390 events.

Imagine a giant inflatable balloon with galaxies painted on it. As it inflates, the pattern stretches and neighboring dots move apart. The rate of that stretching is the Hubble constant. Astronomers usually catch light from distant stars and see how much it has reddened due to the stretching of space.

Gravitational waves are the very trembling of space, born when black holes or other massive bodies collide. Their main oddity isn't that they pass through us, but that they permanently alter the curvature of spacetime and the distances between everything they touch.