Content tagged "galaxies".
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JWST has spotted the 'JWST Quintet' -- at least five galaxies merging just 800 million years after the Big Bang. Gas torn loose in the collision carried oxygen out beyond the galaxies themselves, catching the young universe in the act of distributing heavy elements.
We weigh galaxies by their light, but light comes almost entirely from a handful of massive stars. More than 70% of all stars, by number, are dim and smaller than the Sun. JWST observations now suggest early-universe galaxies could be 3 to 4 times heavier than we thought. SORABUMI explains.
Hubble stared at a patch of darkness one-tenth the size of the full moon for eleven straight days and dug up about 10,000 galaxies. TESS, meanwhile, sweeps the entire sky in one pass. Why does studying the cosmos require such opposite telescopes? SORABUMI breaks down the trade-off between field of view, resolution, and exposure time.
Sunlight left the Sun about eight minutes ago. Light from Proxima Centauri, our nearest star, is about 4.2 years old. The Andromeda Galaxy's light is roughly 2.5 million years old. Because light speed is finite, looking farther always means looking further back in time. SORABUMI translates this into everyday scale to explain why a single glance at the night sky holds hundreds of millions of years at once.
A galaxy in a photograph looks like a cluster of stars, but the real thing extends far beyond that: a diffuse cloud of gas, wider than the visible galaxy, that supplies the raw material for future stars. NASA's small satellite ASPERA is designed to catch this invisible gas in ultraviolet light, and SORABUMI explains how galaxies grow by inhaling and exhaling it.
Supermassive black holes are supposed to sit at the center of their galaxies. But astronomers just found a second one hiding about 2,600 light-years off-center in the same galaxy — roughly a tenth of the distance between the Sun and the Milky Way's core. Close to the center, but not quite there. Here's why.
Newborn star clusters are wrapped in gas cocoons and invisible in optical light. A team led by Stockholm University combed through thousands of clusters with Hubble and JWST and found that massive clusters break free in about 5 million years, while lighter ones take 7 to 8 million — and the heavier ones are the first to light up their galaxy. SORABUMI explains.
We picture black holes as cosmic vacuum cleaners, but the real problem is starvation: food has to come to them. JWST peered into the central 2,000 light-years (618 parsecs) of NGC 4696 and, for the first time, caught 100-million-degree gas condensing into threads that feed a rotating disk — a self-sustaining feeding loop.
Galaxies don't float around randomly. They line up along thread-like structures called filaments, tied together at knots called galaxy clusters. JWST's COSMOS-Web survey has now produced the highest-resolution map of this cosmic web ever made, reaching back to just one billion years after the Big Bang.
Stars, galaxies, gas — everything we can observe makes up just 5% of the universe. The other 95% is something we can't see. Dark matter and dark energy sit at the heart of modern cosmology, and we still don't know what either of them is.