Black Holes Archives

December 22, 2022December 22, 2022 by Evan Gough

A Star Came too Close to a Black Hole. It Didn’t End Well

A disk of hot gas swirls around a black hole in this illustration. The stream of gas stretching to the right is what remains of a star that was pulled apart by the black hole. A cloud of hot plasma (gas atoms with their electrons stripped away) above the black hole is known as a corona. Credits: NASA/JPL-Caltech

Black holes are confounding objects that stretch physics to its limits. The most massive ones lurk in the centers of large galaxies like ours. They dominate the galactic center, and when a star gets too close, the black hole’s powerful gravitational force tears the star apart as they feed on it. Not even the most massive stars can resist.

But supermassive black holes (SMBHs) didn’t start out that massive. They attained their gargantuan mass by accreting material over vast spans of time and by merging with other black holes.

There are large voids in our understanding of how SMBHs grow and evolve, and one way astrophysicists fill those voids is by watching black holes as they consume stars.

December 12, 2022December 12, 2022 by Carolyn Collins Petersen

Black Holes Shouldn’t be Able to Merge, but Dozens of Mergers Have Been Detected. How Do They Do It?

black holes in a globular cluster — This is an artist’s impression created to visualize the concentration of black holes at the center of globular cluster NGC 6397. Credit: ESA/Hubble, N. Bartmann

Who knows what lurks in the hearts of some globular clusters? Astronomers using a collection of gravitational wave observatories found evidence of collections of smaller black holes dancing together as binaries in the hearts of globulars. What’s more, they’ve detected an increased number of gravitational wave events when some of these stellar-mass black holes crashed together.

December 12, 2022December 12, 2022 by Evan Gough

A Black Hole has been Burping for 100 Million Years

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

Black holes are gluttonous behemoths that lurk in the center of galaxies. Almost everybody knows that nothing can escape them, not even light. So when anything made of simple matter gets too close, whether a planet, a star or a gas cloud, it’s doomed.

But the black hole doesn’t eat it at once. It plays with its food like a fussy kid. Sometimes, it spews out light.

When the black hole is not only at the center of a galaxy but the center of a cluster of galaxies, these burps and jets carve massive cavities out of the hot gas at the center of the cluster called radio bubbles.

December 10, 2022December 7, 2022 by Paul M. Sutter

A New Way to Produce Primordial Black Holes in the Early Universe

Exploding primordial black holes could be detected (credit: Wired.com)

Continue reading “A New Way to Produce Primordial Black Holes in the Early Universe”

December 1, 2022December 1, 2022 by Evan Gough

A Black Hole Consumed a Star and Released the Light of a Trillion Suns

A star is being consumed by a distant supermassive black hole. Astronomers call this a tidal disruption event (TDE). As the black hole rips apart the star, two jets of material moving with almost the speed of light are launched in opposite directions. One of the jets was aimed directly at Earth. Image credit: Carl Knox (OzGrav, ARC Centre of Excellence for Gravitational Wave Discovery, Swinburne University of Technology)

When a flash of light appears somewhere in the sky, astronomers notice. When it appears in a region of the sky not known to host a stellar object that’s flashed before, they really sit up and take notice. In astronomical parlance, objects that emit flashing light are called transients.

Earlier this year, astronomers spotted a transient that flashed with the light of a trillion Suns.

November 28, 2022November 28, 2022 by Carolyn Collins Petersen

The Second-Closest Supermassive Black Hole Might be in a Nearby Dwarf Galaxy

Leo 1 dwarf spheroidal galaxy has a supermassive black hole — Leo I appears as a faint patch to the right of the bright star, Regulus. Astronomers say it appears to have a supermassive black hole Credit: Scott Anttila Anttler

There’s a little galaxy in the Milky Way’s cosmic neighborhood called Leo 1. It’s a dwarf spheroidal that lies less than a million light-years away from us. Surprisingly, it has a supermassive black hole about the same mass as Sagittarius A* in our galaxy. That’s unusual in several ways, and astronomers want to know more about it.

November 6, 2022November 2, 2022 by Paul M. Sutter

When Black Holes Collide They Also Produce Neutrinos

Still image from a numerical simulation of an unequal mass binary black hole merger, with parameters consistent with GW190412. [Image credit: N. Fischer, H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetimes project]

Ever since astronomers first detected ultra high energy neutrinos coming from random directions in space, they have not been able to figure out what generates them. But a new hypothesis suggests an unlikely source: the mergers of black holes.

November 5, 2022November 10, 2022 by Brian Koberlein

A Black Hole’s X-Rays are Coming From a Region 2,000 km Away From the Singularity Itself

Artist’s conception of the Cygnus X-1 system. Credit: John Paice

In 1961 astronomers discovered a powerful x-ray source coming from the constellation Cygnus. Not knowing what it was, they named the source Cygnus X-1. It’s one of the strongest x-ray sources in the sky, and we now know it is powered by a stellar-mass black hole. Since it is only about 7,000 light-years away, it also gives astronomers an excellent view of how stellar-mass black holes behave. Even after six decades of study, it continues to teach us a few things, as a recent study in Science shows.

October 31, 2022February 17, 2023 by Matt Williams

Did Supermassive Black Holes Collapse Directly out of Giant Clouds of gas? It Could Depend on Magnetic Fields

This artist’s impression shows a possible seed for the formation of a supermassive black hole. Credit: NASA/CXC/M. Weiss

Roughly half a century ago, astronomers realized that the powerful radio source coming from the center of our galaxy (Sagittarius A*) was a “monster” black hole. Since then, they have found that supermassive black holes (SMBHs) reside at the center of most massive galaxies. This leads to what is known as Active Galactic Nuclei (AGN) or quasars, where the central region of a galaxy is so energetic that it outshines all of the stars in its galactic disk. In all that time, astronomers have puzzled over how these behemoths (which play a crucial role in galactic evolution) originated.

Astronomers suspect that the seeds that formed SMBHs were created from giant clouds of dust that collapsed without first becoming stars – aka. Direct Collapse Black Holes (DCBHs). However, the role of magnetic fields in the formation of DCBHs has remained unclear since none of the previous studies have been able to simulate the full accretion periods. To investigate this, an international team of astronomers ran a series of 3D cosmological magneto-hydrodynamic (MHD) simulations that accounted for DCBH formation and showed that magnetic fields grow with the accretion disks and stabilize them over time.

October 23, 2022October 23, 2022 by Matt Williams

A Black Hole is Hurling a jet of Material at its Neighboring Galaxy

It’s been a banner time for black hole research! In recent months, astrophysicists have announced the discovery of the most powerful gamma-ray burst ever recorded (due to the formation of a black hole), a monster black hole in our cosmic backyard, the frame-dragging effects of a binary black hole, and the remains of the 2017 Kilonova event (spoiler alert: it was a black hole). And with the help of citizen scientists, a team of astronomers recently discovered a unique black hole in a galaxy roughly one billion light-years away that’s hurling a relativistic jet at another galaxy.