Black Holes Archives

May 12, 2022February 1, 2023 by Matt Williams

This is it! Meet the Supermassive Black Hole at the Heart of the Milky Way

This is the first image of Sgr A*, the supermassive black hole at the center of our galaxy. A reanalysis of EHT data by NAOJ scientist suggests its accretion disk may be more elongated than shown in this image. Image Credit: EHT

On April 10^th, 2019, the international consortium known as the Event Horizon Telescope (EHT) announced the first-ever image of a supermassive black hole (SMBH). The image showed the bright disk surrounding the black hole at the center of the M87 galaxy (aka. Virgo A). In 2021, they followed up on this by acquiring an image of the core region of the Centaurus A galaxy and the radio jet emanating from it. Earlier this month, the European Southern Observatory (ESO) announced that the EHT would be sharing the results from its latest campaign – observations of Sagittarius A*!

This supermassive black hole resides at the center of the Milky Way Galaxy, roughly 27,000 light-years from Earth, 44 million km (27.34 million mi) in diameter, and has a mass of 4.31 million Suns. The campaign’s results were shared in an ESO press release and a series of live-streamed press conferences worldwide, including the ESO Headquarters in Munich, Germany. The team’s results (which were shared in six papers) were also published today in a special issue of The Astrophysical Journal Letters.

May 8, 2022May 8, 2022 by Brian Koberlein

A Supermassive Black Hole Just Flipped its Entire Magnetic Field

Artist illustration of the supermassive black hole in 1ES 1927+654 before the flare. Credit: NASA/Sonoma State University, Aurore Simonnet

Black holes are powerful cosmic engines. They provide the energy behind quasars and other active galactic nuclei (AGNs). This is due to the interaction of matter with its powerful gravitational and magnetic fields.

Technically, a black hole doesn’t have a magnetic field on its own, but the dense plasma surrounding the black hole as an accretion disk does. As the plasma swirls around the black hole, the charged particles within it generate an electrical current and magnetic field. The direction of the plasma flow doesn’t change spontaneously, so one would imagine the magnetic field is very stable. So imagine the surprise of astronomers when they saw evidence that a black hole’s magnetic field had undergone a magnetic reversal.

May 5, 2022May 5, 2022 by Paul M. Sutter

NASA Releases a Simulation of 22 Known Black Hole Binary Systems

Gaia BH1 is a Sun-like star co-orbiting with a black hole estimated at 10 times the Sun's mass. Credit: ESO/L. Calcada

Want to take a look at some black hole binary systems? Well then NASA’s got your back with this stunning visual showing 22 confirmed systems.

May 3, 2022May 3, 2022 by Matt Williams

A Space Telescope Could Reveal a Black Hole's Photon Ring

M87 black hole — This view of the M87 supermassive black hole in polarized light highlights the signature of magnetic fields. (Credit: EHT Collaboration)

Despite decades of study, black holes remain one of the most powerful and mysterious celestial objects ever studied. Because of the extreme gravitational forces involved, nothing can escape the surface of a black hole (including light). As a result, the study of these objects has traditionally been confined to observing their influence on objects and spacetime in their vicinity. It was not until 2019 that the first image of a black hole was captured by the Event Horizon Telescope (EHT).

This feat was made possible thanks to a technique known as Very-Long Baseline Interferometry (VLBI), which allowed scientists to see the bright ring surrounding the supermassive black hole (SMBH) at the center of the M87 galaxy. A new study by an international team of astronomers has shown how a space-based interferometry mission could provide reveal even more secrets hiding within the veil of a black hole’s event horizon!

May 3, 2022May 3, 2022 by Carolyn Collins Petersen

Astronomers Discover Eight Echoes from Black Holes

A black hole in an x-ray binary system pulls material away from its neigbor star and into its accretion disk. Credit: Aurore Simonnet and NASA’s Goddard Space Flight Center — A black hole in an x-ray binary system pulls material away from its neighbor star and into its accretion disk. Credit: Aurore Simonnet and NASA’s Goddard Space Flight Center

Black holes are the ultimate space-time sinks in the universe. Anything that wanders too close to one of these monsters gets sucked in, never to be seen again. That includes clouds of gas and dust from nearby stars. It all just disappears down the black hole’s insatiable maw. However, not all is lost. As the black hole feeds on the feast supplied by its neighbors, it gives off bright flashes of X-ray light. In a few places, the light bounces off the train of material spiraling into the black hole. That creates what astronomers call a black hole echo. Now, researchers have found eight of these systems relatively close to us in the Milky Way Galaxy.

May 2, 2022May 2, 2022 by Matt Williams

This is it! On May 12th we’ll see the Event Horizon Telescope’s Image of the Milky Way’s Supermassive Black Hole

This image contains a collage of ESO’s telescopes at various sites in Chile.

In April of 2019, the international astronomical consortium known as the Event Horizon Telescope (EHT) made headlines worldwide when it announced the first-ever image of a black hole. Specifically, the image showed the glowing disk surrounding the supermassive black hole (SMBH) at the center of the M87 galaxy. In 2021, they followed up on this by acquiring an image of the core region of the Centaurus A galaxy and the radio jet emanating from it.

But in what is sure to be the most exciting announcement yet, the European Southern Observatory (ESO) and researchers from the EHT will announce the results of their survey that examined the SMBH at the center of our very own Milky Way Galaxy – Sagittarius A*! The results will be shared as part of a press conference on Thursday, May 12th, starting at 03:00 PM CEST (08:00 EDT; 05:00 PDT). The event will take place at the ESO Headquarters in Munich, Germany, and live-streamed via an ESO webcast.

April 27, 2022April 27, 2022 by Matt Williams

In Some Places, Black Holes are Tearing Apart Thousands of Stars at a Time

Close-up of star near a supermassive black hole (artist’s impression). Credit: ESA/Hubble, ESO, M. Kornmesser

At the heart of the more massive galaxies in the Universe, there are supermassive black holes (SMBHs) so powerful that they outshine all of the stars in their galactic disks. The core regions of these galaxies are known as Active Galactic Nuclei (AGN), or by their more popular-moniker “quasars.” The ongoing study of these objects has provided a testbed for General Relativity and revealed a great deal about the formation and evolution of galaxies and the large-scale structure of the Universe.

If there’s one thing astronomers have observed repeatedly, it is the fact that these massive black holes have massive appetites. In fact, a new survey of over 100 galaxies by the NASA Chandra X-ray Observatory has shown that some supermassive black holes can consume stars by the thousands! These results indicate that some SMBHs needed to consume amounts of stellar matter rarely (if ever) seen in the Universe to grow and reach the sizes that astronomers see today.

April 16, 2022April 16, 2022 by Matt Williams

An Ancestor of Supermassive Black Holes, Found at Cosmic Dawn

An international team of astronomers using archival data from the NASA/ESA Hubble Space Telescope and other space- and ground-based observatories have discovered a unique object in the distant, early Universe that is a crucial link between young star-forming galaxies and the earliest supermassive black holes. Current theories predict that supermassive black holes begin their lives in the dust-shrouded cores of vigorously star-forming “starburst” galaxies.

At the center of the more-massive galaxies in the Universe lie the intensely powerful and energetic phenomena known as supermassive black holes (SMBHs). This includes the SMBH at the center of the Milky Way, the mysterious radio source known as Sagittarius A*. The presence of these black holes causes the nuclei of these galaxies to become particularly energetic – aka., an Active Galactic Nucleus (AGN), or a Quasar – and causes them to outshine all of the other stars in the galactic disk combined.

For decades, astronomers have sought to learn more about SMBHs and their role in the evolution of the cosmos. A particularly burning question is how early SMBHs formed in the Universe, which would place constraints on how they have influenced galaxies over time. In a surprising discovery, an international team observed the ancestor of an SMBH for the first time. This black hole (known as GNz7q) existed during a period known as “Cosmic Dawn,” far earlier than expected.

March 16, 2022March 16, 2022 by Brian Koberlein

A new way to Confirm Hawking's Idea That Black Holes Give off Radiation

In honor of Dr. Stephen Hawking, the COSMOS center will be creating the most detailed 3D mapping effort of the Universe to date. Credit: BBC, Illus.: T.Reyes

Nothing can escape a black hole. General relativity is very clear on this point. Cross a black hole’s event horizon, and you are forever lost to the universe. Except that’s not entirely true. It’s true according to Einstein’s theory, but general relativity is a classical model. It doesn’t take into account the quantum aspects of nature. For that, you’d need a quantum theory of gravity, which we don’t have. But we do have some ideas about some of the effects of quantum gravity, and one of the most interesting is Hawking radiation.

March 3, 2022March 3, 2022 by Evan Gough

It Turns out, the “Closest Black Hole” System Doesn’t Contain a Black Hole At All

New research using data from ESO’s Very Large Telescope and Very Large Telescope Interferometer has revealed that HR 6819, previously believed to be a triple system with a black hole, is in fact a system of two stars with no black hole. The scientists, a KU Leuven-ESO team, believe they have observed this binary system in a brief moment after one of the stars sucked the atmosphere off its companion, a phenomenon often referred to as “stellar vampirism”. This artist’s impression shows what the system might look like; it’s composed of an oblate star with a disc around it (a Be “vampire” star; foreground) and B-type star that has been stripped of its atmosphere (background).

One thousand light-years away is pretty close for a black hole. When researchers discovered a black hole at that distance in 2019, it caught the attention of other astronomers and other interested people. It was the first black hole-hosting stellar system to be seen with the naked eye.

But new research shows that it isn’t there.