black holes tagged posts

Chandra resolves why black holes hit the brakes on growth

Astronomers have an answer for a long-running mystery in astrophysics: why is the growth of supermassive black holes so much lower today than in the past? A study using NASA’s Chandra X-ray Observatory and other X-ray telescopes found that supermassive black holes are unable to consume material as rapidly as they did in the distant past. The results appeared in the December 2025 issue of The Astrophysical Journal.

Ten billion years ago, there was a period that astronomers call “cosmic noon,” when the growth of supermassive black holes (those with millions to billions of times the mass of the sun) was at its peak across the entire history of the universe. Between cosmic noon and now, however, astronomers have seen a major slowdown in how rapidly black holes are growing.

“A longst...

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Researchers solve mystery of universe’s ‘little red dots’

Red dots
The little red dots are young black holes, enshrouded in a cocoon of gas, which they are consuming in order to grow larger. This process generates enormous heat which gives little red dots their unique red colour. Photo: JWST/Darach Watson

Since the James Webb Space Telescope (JWST) went into operation, red dots in its images have puzzled researchers around the world. Now, researchers from the University of Copenhagen have explained these enigmatic findings, revealing the most violent forces in the universe concealed in a cocoon of ionized gas. The discovery is published in Nature.

Since December 2021, when the James Webb super telescope saw first light, some 1...

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Einstein’s theory comes wrapped up with a bow: Astronomers spot star ‘wobbling’ around black hole

An artist's impression depicts the accretion disc surrounding a black hole
An artist’s impression depicts the accretion disc surrounding a black hole, in which the inner region of the disc wobbles. In this context, the wobble refers to the orbit of material surrounding the black hole changing orientation around the central object. Credit NASA.

The cosmos has served up a gift for a group of scientists who have been searching for one of the most elusive phenomena in the night sky. Their study, presented in Science Advances, reports on the very first observations of a swirling vortex in spacetime caused by a rapidly rotating black hole.

The process, known as Lense-Thirring precession or frame-dragging, describes how black holes twist the spacetime that surrounds them, dragging nearby objects like stars and wobbling their orbits along the way.

Discovery of ...

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JWST uncovers hidden black holes devouring stars in dusty galaxies

The James Webb Space Telescope in front of a tidal disruption event, a black hole shredding a star
Caption:Astronomers at MIT, Columbia University, and elsewhere have used NASA’s James Webb Space Telescope to peer through the dust of nearby galaxies and into the aftermath of a black hole’s stellar feast. Credits:Credit: NRAO/AUI/NSF/NASA

Astronomers at MIT, Columbia University, and elsewhere have used NASA’s James Webb Space Telescope (JWST) to peer through the dust of nearby galaxies and into the aftermath of a black hole’s stellar feast.

In a study appearing today in Astrophysical Journal Letters, the researchers report that for the first time, JWST has observed several tidal disruption events—instances when a galaxy’s central black hole draws in a nearby star and whips up tidal forces that tear the star to shreds, giving off an enormous burst of energy in the process.

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