Black Holes Archives

November 21, 2024November 21, 2024 by Matt Williams

New Study Suggests Black Holes Get their “Hair” from their Mothers

This artist’s impression of a supermassive black hole and accretion disk, along with a relativistic jet emanating from its poles. Credit & ©: ESO/L. Calçada

Despite decades of study, black holes are still one of the most puzzling objects in the Universe. As we know from Einstein’s Theory of General Relativity, the gravitational force of these stellar remnants alters the curvature of spacetime around them. This causes gas, dust, and even photons (light) in their vicinity to fall inwards and form disks that slowly accrete onto their faces, never to be seen again. However, astronomers have also noted that they can produce powerful jets that accelerate charged particles to close to the speed of light (aka. relativistic jets).

These jets lead to powerful gamma-ray bursts (GRBs), which have been observed with black holes that have powerful magnetic fields. However, where these magnetic fields come from has remained a mystery to astrophysicists for some time. According to new research led by scientists from the Flatiron Institute, the source of these fields may have finally been revealed. Based on a series of simulations they conducted that modeled the life cycle of stars from birth to collapse, they found that black holes inherit their magnetic fields from the parent stars themselves.

November 20, 2024November 14, 2024 by Paul M. Sutter

Sun-Like Stars Around Black Holes: What Gives?

Illustration of star remnants after it is shredded by a supermassive black hole. Credit: NASA

Buried in the treasure trove of the Gaia catalog were two strange black hole systems. These were black holes orbiting sun-like stars, a situation that astronomers long thought impossible. Recently a team has proposed a mechanism for creating these kinds of oddballs.

November 19, 2024November 14, 2024 by Paul M. Sutter

The Biggest Black Holes May Start From The Tiniest Seeds

An artist's conception of jets protruding from a quasar. Credit: ESO/M. Kornmesser

The existence of gigantic black holes in the very early universe challenges our assumptions of how black holes form and grow. New research suggests that these monsters may have found their origins in the earliest epochs of the Big Bang.

November 14, 2024November 14, 2024 by Brian Koberlein

Two Supermassive Black Holes on the Verge of a Merger

A pair of monster black holes swirl in a cloud of gas in this artist’s concept of AT 2021hdr. Credit: NASA/Aurore Simonnet (Sonoma State University)

In March 2021, astronomers observed a high-energy burst of light from a distant galaxy. Assigned the name AT 2021hdr, it was thought to be a supernova. However, there were enough interesting features that flagged as potentially interesting by the Automatic Learning for the Rapid Classification of Events (ALeRCE). In 2022, another outburst was observed, and over time the Zwicky Transient Facility (ZTF) found a pattern of outbursts every 60–90 days. It clearly wasn’t a supernova, but it was unclear on what it could be until a recent study solved the mystery.

November 14, 2024November 14, 2024 by Brian Koberlein

Astronomers Map the Shape of a Black Hole's Corona for the First Time

Illustration of material swirling around a black hole highlights the corona, that shines brightly in X-ray light. Credit: NASA/Caltech-IPAC/Robert Hurt

If you were lucky enough to observe a total eclipse, you are certain to remember the halo of brilliant light around the Moon during totality. It’s known as the corona, and it is the diffuse outer atmosphere of the Sun. Although it is so thin we’d consider it a vacuum on Earth, it has a temperature of millions of degrees, which is why it’s visible during a total eclipse. According to our understanding of black hole dynamics black holes should also have a corona. And like the Sun’s corona, it is usually difficult to observe. Now a study in The Astrophysical Journal has made observations of this elusive region.

November 12, 2024November 12, 2024 by Mark Thompson

Early Black Holes Fed 40x Faster than Should Be Possible

This artist’s illustration shows a red, early-Universe dwarf galaxy that hosts a rapidly feeding black hole at its center. Using data from NASA's JWST and Chandra X-ray Observatory, a team of U.S. National Science Foundation NOIRLab astronomers have discovered this low-mass supermassive black hole at the center of a galaxy just 1.5 billion years after the Big Bang. It is accreting matter at a phenomenal rate — over 40 times the theoretical limit. While short lived, this black hole’s ‘feast’ could help astronomers explain how supermassive black holes grew so quickly in the early Universe.

The theory goes that black holes accrete material, often from nearby stars. However the theory also suggests there is a limit to how big a black hole can grow due to accretion and certainly shouldn’t be as large as they are seen to be in the early Universe. Black holes it seems, are fighting back and don’t care about those limits! A recent study shows that supermassive black holes are growing at rates that defy the limits of current theory. Astronomers just need to figure out how they’re doing it!

November 11, 2024November 11, 2024 by Evan Gough

How Did Supermassive Black Holes Get So Big, So Early? They Might Have Had a Head Start

An artist's illustration of a supermassive black hole (SMBH.) The JWST has revealed SMBHs in the early Universe that are much more massive than our scientific models can explain. Could primordial black holes have acted as "seeds" for these massive SMBHs? Image Credit: ESA

Supermassive Black Holes (SMBHs) can have billions of solar masses, and observational evidence suggests that all large galaxies have one at their centres. However, the JWST has revealed a foundational cosmic mystery. The powerful space telescope, with its ability to observe ancient galaxies in the first billion years after the Big Bang, has shown us that SMBHs were extremely massive even then. This contradicts our scientific models explaining how these behemoths became so huge.

How did they get so massive so early?

November 9, 2024November 9, 2024 by Brian Koberlein

Using Light Echoes to Find Black Holes

Light near a black hole can travel different paths to create echoes of a single flash. Credit: Wong, et al

The most amazing thing about light is that it takes time to travel through space. Because of that one simple fact, when we look up at the Universe we see not a snapshot but a history. The photons we capture with our telescopes tell us about their journey. This is particularly true when gravity comes into play, since gravity bends and distorts the path of light. In a recent study, a team shows us how we might use this fact to better study black holes.

November 8, 2024November 8, 2024 by Evan Gough

A Star Disappeared in Andromeda, Replaced by a Black Hole

This Illustration shows a failed supernova turning directly into a black hole without an explosion. Credit: NASA/ESA/P. Jeffries (STScI)

Massive stars about eight times more massive than the Sun explode as supernovae at the end of their lives. The explosions, which leave behind a black hole or a neutron star, are so energetic they can outshine their host galaxies for months. However, astronomers appear to have spotted a massive star that skipped the explosion and turned directly into a black hole.

November 5, 2024November 5, 2024 by Brian Koberlein

We Understand Rotating Black Holes Even Less Than We Thought

Illustration of an exotic black hole. Credit: Alex Antropov, via Pixabay

Black holes are real. We see them throughout the cosmos, and have even directly imaged the supermassive black hole in M87 and our own Milky Way. We understand black holes quite well, but the theoretical descriptions of these cosmic creatures still have nagging issues. Perhaps the most famous issue is that of the singularity. According to the classical model of general relativity, all the matter that forms a black hole must be compressed into an infinite density, enclosed within a sphere of zero volume. We assume that somehow quantum physics will avert this problem, though without a theory of quantum gravity, we aren’t sure how. But the singularity isn’t the only infinite problem. Take, for example, the strange boundary known as the Cauchy horizon.