Event Horizon Telescope Archives

December 22, 2024December 22, 2024 by Matt Williams

M87 Releases a Rare and Powerful Outburts of Gamma-ray Radiation

A Hubble Space Telescope image of the giant galaxy M87 shows a 3,000-light-year-long jet of plasma blasting from the galaxy's 6.5-billion-solar-mass central black hole. The blowtorch-like jet seems to cause stars to erupt along its trajectory. These novae are not caught inside the jet, but are apparently in a dangerous neighbourhood nearby. During a recent 9-month survey, astronomers using Hubble found twice as many of these novae going off near the jet as elsewhere in the galaxy. The galaxy is the home of several trillion stars and thousands of star-like globular star clusters. [Image description: A Hubble photo of galaxy M87, which resembles a translucent, fuzzy white cotton ball. The brightness decreases gradually out in all directions from a bright white point of light at the centre. A wavy blue-white jet of material extends from the point-like core outward to the upper right, about halfway across the galaxy. Stars speckle the background.]

In April 2019, the Event Horizon Telescope (EHT) collaboration made history when it released the first-ever image of a black hole. The image captured the glow of the accretion disk surrounding the supermassive black hole (SMBH) at the center of the M87 galaxy, located 54 million light-years away. Because of its appearance, the disk that encircles this SMBH beyond its event horizon (composed of gas, dust, and photons) was likened to a “ring of fire.” Since then, the EHT has been actively imaging several other SMBH, including Sagittarius A* at the center of the Milky Way!

In addition, the EHT has revealed additional details about M87, like the first-ever image of a photon ring and a picture that combines the SMBH and its relativistic jet emanating from its center. Most recently, the EHT released the results of its latest observation campaign. These observations revealed a spectacular flare emerging from M87’s powerful relativistic jet. This flare released a tremendous amount of energy in multiple wavelengths, including the first high-energy gamma-ray outburst observed in over a decade.

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.

September 4, 2024September 4, 2024 by Mark Thompson

Simulating the Accretion Disk Around a Black Hole

Supercomputer simulations reveals the nature of turbulence in black hole accretion disks

Black holes are by their very nature, challenging to observe and difficult to spot. It’s usually observations of the accretion disk that reveal properties of the hidden black hole. There is often enough material within the accretion disk to make them shine so brightly that they can often be among the brightest objects in space. A wonderful image has been released which shows the highest resolution simulation of a black hole accretion disk ever created.

July 23, 2024July 23, 2024 by Mark Thompson

Next Generation Event Horizon Telescope To Unlock Mysteries of Black Holes

Impact of scattering on the observed polarimetric spiral phase from one 345 GHz frame of the GRMHD simulation of Sgr A*

The prospect of actually resolving the event horizon of black holes feels like the stuff of science fiction yet it is a reality. Already the Event Horizon Telescope (EHT) has resolved the horizon of the black holes at the centre of the Milky Way and M87. A team of astronomers are now looking to the next generation of the EHT which will work at multiple frequencies with more telescopes than EHT. A new paper suggests it may even be possible to capture the ring where light goes into orbit around the black hole at the centre of the Milky Way.

June 30, 2024June 30, 2024 by Mark Thompson

What’s Next for the Event Horizon Telescope? Twelve Possible New Targets

Both the Milky Way and a galaxy known as M87 have supermassive black holes at their core. These are the two largest black holes we know about and the Event Horizon Telescope has just captured stunning images of their event horizons. A new paper looks at what we might expect from a next generation EHT and highlights twelve targets that should be top of the list.

May 29, 2024May 29, 2024 by Laurence Tognetti

Black Holes: Why study them? What makes them so fascinating?

Simulation of a black hole. (Credit: NASA/ESA/Gaia/DPAC)

Over the last few months, Universe Today has explored a plethora of scientific fields, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, radio astronomy, extremophiles, and organic chemistry, and how these various disciplines help scientists and the public better understand our place in the cosmos.

March 27, 2024March 27, 2024 by Alan Boyle

New View Reveals Magnetic Fields Around Our Galaxy’s Giant Black Hole

An image from the Event Horizon Telescope shows lines of polarization, a signature of magnetic fields, around the shadow of the Milky Way's central supermassive black hole. Astronomers want to know how massive black holes like this one formed early in cosmic history. (Credit: EHT Collaboration)

Fresh imagery from the Event Horizon Telescope traces the lines of powerful magnetic fields spiraling out from the edge of the supermassive black hole at the center of our Milky Way galaxy, and suggests that strong magnetism may be common to all supermassive black holes.

February 10, 2024February 10, 2024 by Brian Koberlein

The Event Horizon Telescope Zooms in on a Black Hole's Jet

The jet of the black hole in 3C 84 at different spatial scales. Credit: Georgios Filippos Paraschos (MPIfR)

Although supermassive black holes are common throughout the Universe, we don’t have many direct images of them. The problem is that while they can have a mass of millions or billions of stars, even the nearest supermassive black holes have tiny apparent sizes. The only direct images we have are those of M87* and Sag A*, and it took a virtual telescope the size of Earth to capture them. But we are still in the early days of the Event Horizon Telescope (EHT), and improvements are being made to the virtual telescope all the time. Which means we are starting to look at more supermassive black holes.

December 9, 2023December 9, 2023 by Mark Thompson

What Could a Next Generation Event Horizon Telescope Do?

Image of the M87 black hole by EHT and a CGI image photon ring. Image credit: EHT, Center for Astrophysics | Harvard & Smithsonian

Telescopes have come a long way in a little over four hundred years! It was 1608 that Dutch spectacle maker Hans Lippershey who was said to be working with a case of myopia and, in working with lenses discovered the magnifying powers if arranged in certain configurations. Now, centuries on and we have many different telescope designs and even telescopes in orbit but none are more incredible than the Event Horizon Telescope (EHT). Images las year revealed the supermassive black hole at the centre of our Galaxy and around M87 but now a team of astronomers have explored the potential of an even more powerful system the Next Generation EHT (ngEHT).

June 15, 2023June 15, 2023 by Matt Williams

Pulsars Could Help Map the Black Hole at the Center of the Milky Way

The Atacama Large Millimeter/submillimeter Array (ALMA) looked at Sagittarius A*, (image of Sag A* by the EHT Collaboration) to study something bright in the region around Sag A*. Credit: ESO/José Francisco Salgado.

The Theory of General Relativity (GR), proposed by Einstein over a century ago, remains one of the most well-known scientific postulates of all time. This theory, which explains how spacetime curvature is altered in the presence of massive objects, remains the cornerstone of our most widely-accepted cosmological models. This should come as no surprise since GR has been verified nine ways from Sunday and under the most extreme conditions imaginable. In particular, scientists have mounted several observation campaigns to test GR using Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.

Last year, the Event Horizon Telescope (EHT) – an international consortium of astronomers and observatories – announced they had taken the first images of Sag A*, which came just two years after the release of the first-ever images of an SMBH (M87). In 2014, the European members of the EHT launched another initiative known as BlackHoleCam to gain a better understanding of SMBHs using a combination of radio imaging, pulsar observations, astrometry, and GR. In a recent paper, the BHC initiative described how they tested GR by observing pulsars orbiting Sgr A*.