metallicity

A thin film of neodymium nickelate, fifteen nanometers thick, sits on a neodymium gallate substrate. Below one hundred eighty kelvin it behaves as an insulator: electrons are locked inside their atomic cells and cannot move freely.

Imagine three witnesses who saw the same event. Two tell the same story, the third tells a different one. Whom do you believe? This is exactly the situation in astronomy when measuring carbon in the star J0815+4729, an ancient object with a record-low iron abundance (carbon is one of the key elements used to infer the properties of the…

Imagine three witnesses who saw the same event. Two tell the same story, the third tells a different one. Whom do you believe? This is exactly the situation in astronomy when measuring carbon in the star J0815+4729, an ancient object with a record-low iron abundance (carbon is one of the key elements used to infer the properties of the…

Forty light-years away lives a star that went unnoticed for a long time: TRAPPIST-1 emits two thousand times less light than the Sun. But it turned out to have seven Earth-sized planets, three of which orbit in the zone where water could remain liquid. Yet little was known about the star itself, about its chemical kitchen.

Forty light-years away lives a star that went unnoticed for a long time: TRAPPIST-1 emits two thousand times less light than the Sun. But it turned out to have seven Earth-sized planets, three of which orbit in the zone where water could remain liquid. Yet little was known about the star itself, about its chemical kitchen.

In a distant galaxy, light from hot gas should reveal its composition. The James Webb Telescope split that light into a spectrum, and astronomers saw: oxygen lines too weak.

In a distant galaxy, light from hot gas should reveal its composition. The James Webb Telescope split that light into a spectrum, and astronomers saw: oxygen lines too weak.

Faint galaxies scattered across the Perseus cluster are like ghosts among their bright neighbors. They are so diffuse that distant objects shine through them, and they contain hundreds of times fewer stars than our Milky Way.

Two stars, AF Lep A and ε Indi A, have become the focus of close attention. Using the GHOST spectrograph on the Gemini telescope, astronomers split their light into colors and, from absorption lines, determined how much carbon, oxygen, sulfur, and thirteen other elements are in the stars' atmospheres.

Two spinning tops whirl so close they nearly touch. One is scorching blue, the other dim white. Together they complete a full orbit in twenty hours. This is the pair Feige 64: a blue star with a mass of just a third of the Sun's, and a white dwarf, the cooled core of a former star, one and a half times heavier than our Sun. The blue star seems too hot for its mass.

A star is not just a distant sun. It's a cradle for planets, and its light carries the birth story of the entire system. The chemical composition of a star is its DNA. Astronomers peer into this DNA to understand why some stars host rocky worlds like Earth, while others host gas giants.

A sunspot, a dark island on the fiery surface, lives its own turbulent life. Beneath it, in invisible depths, giant magnetic loops drift like twisted cables. When such a loop emerges, it can discharge as a flare, and hurl clouds of charged particles into space. Scientists have long tried to understand what determines the strength and suddenness of these events.

The five-hundred-meter FAST radio telescope picked up a signal at the 21-centimeter wavelength — the telltale glow of cold hydrogen. The signal came from a cloud named Cloud-9. It hangs in space near the galaxy M94, but it contains not a single star.

In 1,433 pairs of galaxies scattered across the sky, astronomers noticed an unusual pattern. Neighbors located 'above' or 'below' a massive stellar system contain up to a quarter more oxygen than those lying in the plane of its disk.

The Sun is a giant cauldron where light struggles through a thick layer of scorching matter. On its way out, photons (light particles) constantly bump into atoms and lose energy. How strongly matter holds back light is called "opacity," and it determines how quickly heat escapes. Iron is one of the main culprits for opacity in the Sun's interior.

The star AB Aur is young, about 4 million years old. Around it swirls a dense disk of gas and dust. Recently, a long gas stream, a flow of material from the surrounding cloud, crashed into it.

15 175 107 stars. Each one got an age. But no number is free of uncertainty: a star's age isn't a nail hammered into the timeline: it's a probability cloud, a fog hiding the true value. For galactic evolution, such a timestamp is priceless: without it, the map of the Milky Way remains flat.

For thirteen billion years, light battled through cosmic emptiness. It bent around massive galaxy clusters that, as Einstein predicted, acted as giant lenses — amplifying and distorting the distant glow. In 2023, the NIRSpec instrument on the James Webb Space Telescope captured this light and spread it into spectra.

A star's age is the key to the galaxy's history. But prying that key from nature is no simple task: unlike a tree, a star doesn't grow annual rings. Yet, its atmosphere holds a chemical code — the ratio of elements that slowly shifted as generations of stars died and new ones were born.

In a giant cosmic cradle, the Tarantula Nebula, astronomers took a close look at 122 massive stars, each at least 30 times heavier than the Sun. They measured the nitrogen abundance in their atmospheres, and the picture turned out to be unexpected.

Every star is a living archive, and its spectrum a multilayered manuscript. Over billions of years, the history of the galaxy is written into it: the galactic chemical evolution of the Milky Way leaves a smooth trace in elemental abundances.

For years, the Sun teased astrophysicists. In its atmosphere, refractory elements, like spices in a basic recipe, were slightly less abundant than in nearly identical twin stars. Suspicion arose: could our star be modest, skipping the planetary "dessert" that others devour with gusto?

At the center of attention are tiny stellar cities: ultra-faint dwarf galaxies. They resemble sparse swarms of fireflies circling within a vast invisible cloud. This cloud is a halo of ultralight dark matter. Its particles are so light that they behave not like billiard balls but like waves.

Imagine a forest planted in a single day. At first glance, all trees look alike, but their cross sections tell different stories: some grew on clean soil, others on the ashes of ancient fires.

In the scorching core of a star, two helium nuclei approach each other like two dancers on a crowded stage. Their dance is alpha scattering, the basis of stellar helium burning. How smoothly they twirl determines how quickly the star burns its fuel. Previously, this dance was described in simplified terms.

Deep beneath our feet, in the scorching mantle, iron leads a double life. It can be divalent or trivalent, like a coin that lands heads or tails. Which side dominates determines how much oxygen stays in the planet's rocky shell and how much sinks into the core.

A chef doesn't waste ingredients cooking the whole dish to check the taste: they just taste a drop of sauce. The same logic underlies the "information matching" method for predicting metal strength. Instead of expensive calculations of every atom's behavior, scientists "taste" only simple indicators linked to plasticity — a metal's ability to bend without breaking.

In astrophysics, some numbers seem random yet recur with the persistence of a spell. One such number is the ratio of X-ray brightness to H-alpha hydrogen emission in turbulent gas tails. From galactic winds to ‘jellyfish’ slicing through clusters, this ratio steadily holds at around three.

Elliptical galaxies are quiet stellar metropolises in retirement. By all rights, their light should be calm, reddish, like a sunset. But their spectra scream otherwise: in the far ultraviolet, these old-timers blaze like holiday lights. For three decades, astronomers have puzzled over this 'ultraviolet upturn' (UV upturn).

The search for extraterrestrial intelligence is like panning for gold in an endless river. For decades, SETI has been listening to the hum of the Galaxy, but the ether is silent. It’s not about antenna sensitivity — it’s that we don’t know where to dip our pan.

Astronomers using the JWST (James Webb Space Telescope) have for the first time studied in detail the atmosphere of a young exoplanet, V1298 Tau c. This super-Earth, a planet more massive than Earth but less so than gas giants, is only 23 million years old.

Toss a handful of coins on a table: each one lands heads or tails on its own. Now imagine the coins start flipping over, nudging each other. That's roughly how neutrinos behave in a very dense environment.

An archaeologist holds in their hands not a clay shard but an actual star — a living snapshot of the era when the universe was just learning to produce anything heavier than lithium. That is exactly the kind of find astronomers describe in a new study. They spotted four dim stars so ancient and pristine in composition that their matter is barely diluted by the 'cosmic dust' of later generations.

A chef pours hot sugar syrup onto a cold table, and it sets into crystals. That's roughly how engineers pictured metal solidification: the liquid instantly becomes a scatter of crystalline grains. But close-up imaging revealed an extra stage wedged between liquid and solid.

When the interstellar comet 3I/ATLAS approached the Sun, its tail lit up with a metallic sheen, as if a tin can full of nickel and iron had burst open. By breaking down its light into colors, astronomers detected the lines of these metals using spectral analysis.

A tiny grain of sand, older than Earth, was found in the meteorite Meteorite Hills 00526. It measures about one thousandth of a millimeter. It consists of three parts: a silicate with magnesium and calcium, aluminum oxide, and a speck of titanium oxide.

Steel is not a monolith but a mosaic of microscopic grains fused together. Their seams, the grain boundaries, are the most vulnerable spots: this is where cracks begin. Impurity atoms, even in negligible amounts, accumulate at these seams like sand between gears, and they can either lubricate the mechanism or jam it completely.

Two lamps in a shop window: one glows with a cool, bluish light, the other a bit warmer and yellower. That's roughly how the two types of supernovae, Ib and Ic, look when astronomers view them through a telescope.

There is something wildly generous about a garden where the first flowers don't just bloom but immediately scatter their seeds far beyond the fence. Something similar was happening in the young universe.

The halo of our Galaxy is a huge, sparse cloud of old stars that envelops the familiar disk. It holds the story of how the Milky Way grew by gobbling up neighboring dwarf galaxies.