tidal disruption event

Far away in the constellation Cancer, 3.5 billion light-years from Earth, a pendulum clock is ticking. The pendulum is a secondary black hole orbiting a much more massive primary.

In active galactic nuclei, supermassive black holes are surrounded by a dense ring of dust that acts like a curtain: it hides everything happening at the center. If a star ventures too close to the black hole, tidal forces tear it apart, and the resulting flare is usually visible in optical and X-ray light.

In active galactic nuclei, supermassive black holes are surrounded by a dense ring of dust that acts like a curtain: it hides everything happening at the center. If a star ventures too close to the black hole, tidal forces tear it apart, and the resulting flare is usually visible in optical and X-ray light.

A million orbits: the same score. Nine dark matter halos: nine orchestras without a conductor. All musicians play from the same notes, but in each hall the music sounds different: sometimes in tune, sometimes out of sync. Likewise, satellite galaxies falling into a host halo follow orbits that depend not only on mass but also on the shape of the invisible stage.

A balloon that lets out air in bursts zips around the room — the jet blasts first one way, then another. A dying star behaves the same way as it sheds its bloated shell. Only instead of air, it's superheated gas, and instead of a balloon, it's a future white dwarf (the dense stellar remnant about the size of Earth).

The merger of two neutron stars is not just a collision. Even before they touch, they deform each other through tidal forces, and this deformation depends on how 'soft' or 'stiff' the matter inside is. Stiff matter resists more; soft matter changes shape more easily.

The birth of a moon is a cosmic car crash. Two young planets collide, and a cloud of scorching debris swirls around the surviving world. From this disk, like clay on a potter's wheel, a satellite gradually takes shape. That's probably how our Moon came to be.

The cosmic detective story began with a quiet flash in the optical band. AT2019wzc slowly brightened and faded like a smoldering ember. But hidden inside was something more energetic — repeating soft X-ray bursts that astronomers call quasi-periodic eruptions. These eruptions last minutes to hours and repeat every few hours or days.

The cosmic detective story began with a quiet flash in the optical band. AT2019wzc slowly brightened and faded like a smoldering ember. But hidden inside was something more energetic — repeating soft X-ray bursts that astronomers call quasi-periodic eruptions. These eruptions last minutes to hours and repeat every few hours or days.

A cosmic object spins, but its shadow isn't round. Astrophysicists examined a black hole in an unusual version of gravity — the so-called brane world (where our universe is a three-dimensional surface in a space of higher dimensions).

The ocean bulges toward the Moon in a tidal hump. But some objects do the opposite — instead of stretching matter, the tide presses a dent into it. These are boson stars: invisible clumps of boson particles that can all collapse into a single quantum state. Normal matter is propped up by heat; boson stars are held together by quantum pressure.

A star circles a rotating black hole like a figure skater at the center of a rink. While it is far away and can be treated as a point, the dance remains predictable: the orbit follows clear laws, like music that is easy to glide to. But as it approaches, gravity begins to act unevenly.

A gas disk with a mass of four hundred thousand suns encircles the black hole at the center of the Milky Way. Its gravity works like a gravitational rudder: slowly but inexorably turning the orbits of binary stars, driving them into the region where tidal forces tear the pair apart.

A gas disk with a mass of four hundred thousand suns encircles the black hole at the center of the Milky Way. Its gravity works like a gravitational rudder: slowly but inexorably turning the orbits of binary stars, driving them into the region where tidal forces tear the pair apart.

Two neutron stars whirl in a close dance, each feeling the tidal field of its partner. It's like the Moon raising oceans on Earth, but here it's spacetime itself and the star's matter that deform. Astrophysicists call this tidal deformation — a measure of how much an object 'bends' under the gravitational pull of its companion.

A branch falls into a whirlpool. It gets spun and broken, but sometimes a powerful fountain of water bursts from the center. Similarly, a black hole tears apart a passing star, and occasionally a blinding plasma jet, a jet, shoots into space.

A campfire burns steadily and long. But when the wind blows, the flame flickers out, leaving only embers. A similar story plays out with the gravastar — a hypothetical object that was supposed to replace the black hole. An ordinary black hole hides a singularity — a point where the laws of physics break down.

A star runs out of fuel and rapidly collapses under its own gravity. According to classical ideas, it collapses into a point of infinite density — a singularity. But what if nature abhors infinities? In models of regular black holes, instead of a singularity, a dense core of unknown matter forms at the center.

Every 165 days, the giant planet dives toward its star, nearly grazing its fiery corona, then flies off into the icy void. This is TIC 241249530 b — an exoplanet with a record eccentricity of 0,94.

When a star ventures too close to a supermassive black hole, a cosmic requiem plays out — a tidal disruption event. Thanks to photometry and spectroscopy, astronomers discern every instrument in this orchestra.

The death of a massive star is not just the flash of a supernova, but also the birth of a black hole.

The cosmos is full of screams we can't hear. Every time a black hole tears a star apart, a blinding flash is born, and often — a narrow relativistic jet, shooting out thousands of light-years. But if that searchlight is aimed away from Earth, we see only a faint afterglow — a radio echo arriving with a delay.

Dwarf galaxies orbiting the Milky Way look as if they’ve survived a gravitational storm. Their stellar bodies are stretched, scattered by tidal tails, and heated from within.

In the centers of distant galaxies, X-ray 'beacons' sometimes light up. They don't flash randomly but on a strict schedule: every few hours or days. These bursts are called quasi-periodic eruptions (repeating at nearly regular intervals).

A black hole, like a spinning wheel, twists a cloud of light particles, axions, around itself. These particles are the leading candidates for dark matter. The cloud follows the laws of quantum mechanics, resembling a giant atom: there are levels, and there are transitions between them.

A black hole is like a spinning drop of viscous liquid. Normally, such a drop tends to stay whole: splitting would reduce its surface area, which contradicts the law of non-decrease of entropy (a measure of disorder, like a broken cup doesn't glue itself back together).

In the boundless night of space, galaxies come together in a slow gravitational dance, merging into one. Such collisions are not head-on impacts but rather like fingers moving slowly through water, leaving swirls and tails behind.

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.

When two neutron stars circle each other, they don't remain rigid spheres. The partner's gravity stretches each star, creating tidal bulges — much like the Moon raises ocean tides on Earth. But unlike water, here it's superdense matter that deforms: a teaspoon of this stuff weighs billions of tons.

The ocean bulges a full meter under the Moon: that's a tide. If a massive body sits near a black hole, the hole feels a tidal pull too. In ordinary Einsteinian gravity, it doesn't respond to such a static tide: its "tidal numbers" (measures of deformability) are zero.

On the periphery of the Solar System lurk thousands of objects comparable in size to an exoplanet — a body of planetary mass not bound to our star. Their orbits are chaotic, and from time to time the trajectory of such a wanderer crosses Earth's path.

When two superdense stars circle in a tight dance, the space around them shudders. This shudder, gravitational waves, is caught by giant detectors on Earth. But deciphering the signal is tricky: you need to figure out what exactly you're dealing with — a pair of black holes or neutron stars.

When a piano falls into an abyss, we think about the abyss. We don't think about the piano's cover. In much the same way, astrophysicists have for decades studied extreme close encounters between small bodies and massive black holes. They focused on the black hole itself and what orbits it. But what the 'bullet'—the small object heading toward doom — is wearing, almost no one asked.

A blob of cold helium swoops dangerously close to a black hole. But this isn't just a blob: it's a dead star the size of Earth, yet with a mass comparable to the Sun's.

A black hole is not an eternal vacuum cleaner. Left alone in the void, it slowly disappears, radiating energy like a puddle drying on asphalt. This process, predicted by Stephen Hawking, is called evaporation.

In the accretion disks that gird the nuclei of active galaxies (quasars, discovered by Maarten Schmidt way back in the 1960s) a river of incandescent gas and dust churns. In its backwaters, where turbulent flows subside, against all odds, planets are born.

The universe is full of the invisible. We know about dark matter from galaxy rotation and gravitational lensing, but its nature has eluded us for a century.

When two neutron stars, compressed to the size of a city, approach in their final dance, the spacetime around them comes alive, emitting gravitational waves.

Picture a tightrope walker balancing over an abyss. Every step changes the rope's tension, and the slightest shift in center of gravity can prove fatal. That's roughly what the dance of an ordinary sun-like star around a black hole of ten solar masses looks like when the orbit is highly elongated.

Eight hundred million years ago, in the main asteroid belt, a giant inkwell shattered. The parent body, over a hundred kilometers in diameter, made of primitive carbonaceous chondrites, suddenly broke apart near the J3:1 resonance with Jupiter.