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Lone Black Holes Discovered Adrift in the Galaxy
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By NASA
5 min read
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The blazar BL Lacertae, a supermassive black hole surrounded by a bright disk and jets oriented toward Earth, provided scientists with a unique opportunity to answer a longstanding question: How are X-rays generated in extreme environments like this?
NASA’s IXPE (Imaging X-ray Polarimetry Explorer) collaborated with radio and optical telescopes to find answers. The results (preprint available here), to be published in the journal Astrophysical Journal Letters, show that interactions between fast-moving electrons and particles of light, called photons, must lead to this X-ray emission.
This artist’s concept depicts the central region of the blazar BL Lacertae, a supermassive black hole surrounded by a bright disk and a jet oriented toward Earth. The galaxy’s central black hole is surrounded by swirls of orange in various shades representing the accretion disk of material falling toward the black hole. While black holes are known for pulling in material, this accretion process can result in the ejection of jets of electrons at nearly the speed of light. The jet of matter is represented by the cone of light that starts at the center of the black hole and widens out as it reaches the bottom of the image. It is streaked with lines of white, pink and purple which represent helix-shaped magnetic fields. We can observe these jets in many wavelengths of light including radio, optical, and X-ray. NASA’s Imaging X-ray Polarimetry Explorer (IXPE) recently collaborated with radio and optical telescopes to observe this jet and determine how the X-rays are generated in these types of celestial environments.NASA/Pablo Garcia Scientists had two competing possible explanations for the X-rays, one involving protons and one involving electrons. Each of these mechanisms would have a different signature in the polarization of X-ray light. Polarization is a property of light that describes the average direction of the electromagnetic waves that make up light.
If the X-rays in a black hole’s jets are highly polarized, that would mean that the X-rays are produced by protons gyrating in the magnetic field of the jet or protons interacting with jet’s photons. If the X-rays have a lower polarization degree, it would suggest that electron-photons interactions lead to X-ray production.
IXPE, which launched Dec. 9, 2021, is the only satellite flying today that can make such a polarization measurement.
“This was one of the biggest mysteries about supermassive black hole jets” said Iván Agudo, lead author of the study and astronomer at the Instituto de Astrofísica de Andalucía – CSIC in Spain. “And IXPE, with the help of a number of supporting ground-based telescopes, finally provided us with the tools to solve it.”
Astronomers found that electrons must be the culprits through a process called Compton Scattering. Compton scattering (or the Compton effect) happens when a photon loses or gains energy after interacting with a charged particle, usually an electron. Within jets from supermassive black holes, electrons move near the speed of light. IXPE helped scientists learn that, in the case of a blazar jet, the electrons have enough energy to scatter photons of infrared light up to X-ray wavelengths.
BL Lacertae (BL Lac for short) is one of the first blazars ever discovered, originally thought to be a variable star in the Lacerta constellation. IXPE observed BL Lac at the end of November 2023 for seven days along with several ground-based telescopes measuring optical and radio polarization at the same time. While IXPE observed BL Lac in the past, this observation was special. Coincidentally, during the X-ray polarization observations, the optical polarization of BL Lac reached a high number: 47.5%.
“This was not only the most polarized BL Lac has been in the past 30 years, this is the most polarized any blazar has ever been observed!” said Ioannis Liodakis, one of the primary authors of the study and astrophysicist at the Institute of Astrophysics – FORTH in Greece.
IXPE found the X-rays were far less polarized than the optical light. The team was not able to measure a strong polarization signal and determined that the X-rays cannot be more polarized than 7.6%. This proved that electrons interacting with photons, via the Compton effect, must explain the X-rays.
The fact that optical polarization was so much higher than in the X-rays can only be explained by Compton scattering.
Steven Ehlert
Project Scientist for IXPE at Marshall Space Flight Center
“The fact that optical polarization was so much higher than in the X-rays can only be explained by Compton scattering”, said Steven Ehlert, project scientist for IXPE and astronomer at the Marshall Space Flight Center.
“IXPE has managed to solve another black hole mystery” said Enrico Costa, astrophysicist in Rome at the Istituto di Astrofísica e Planetologia Spaziali of the Istituto Nazionale di Astrofísica. Costa is one of the scientists who conceived this experiment and proposed it to NASA 10 years ago, under the leadership of Martin Weisskopf, IXPE’s first principal investigator. “IXPE’s polarized X-ray vision has solved several long lasting mysteries, and this is one of the most important. In some other cases, IXPE results have challenged consolidated opinions and opened new enigmas, but this is how science works and, for sure, IXPE is doing very good science.”
What’s next for the blazar research?
“One thing we’ll want to do is try to find as many of these as possible,” Ehlert said. “Blazars change quite a bit with time and are full of surprises.”
More about IXPE
IXPE, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. IXPE is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama. BAE Systems, Inc., headquartered in Falls Church, Virginia, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder. Learn more about IXPE’s ongoing mission here:
https://www.nasa.gov/ixpe
Elizabeth Landau
NASA Headquarters
elizabeth.r.landau@nasa.gov
202-358-0845
Lane Figueroa
Marshall Space Flight Center, Huntsville, Ala.
lane.e.figueroa@nasa.gov
256.544.0034
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Last Updated May 06, 2025 EditorBeth RidgewayContactElizabeth R. Landauelizabeth.r.landau@nasa.govLocationMarshall Space Flight Center Related Terms
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Black Holes
Black Holes Black holes are among the most mysterious cosmic objects, much studied but not fully understood. These objects aren’t…
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By USH
Several days ago, a massive blackout swept across large parts of Spain, Portugal, and parts of southern France. Millions were left without power as the interconnected European energy grid experienced a rare and abrupt failure. While authorities quickly pointed to a "rare atmospheric phenomenon" as the cause, not everyone is convinced.
Here are some explanations of authorities as well as controversial theories:
According to REN, Portugal’s national electricity grid operator, the blackout was triggered by a fault originating in Spain’s power infrastructure. The disruption, they claim, was linked to "induced atmospheric variation", a term referring to extreme temperature differences that led to anomalous oscillations in high-voltage transmission lines. These oscillations reportedly caused synchronization failures between regional grid systems, ultimately sparking a chain reaction of failures across the European network.
What makes the situation even more intriguing is that just days before the blackout, Spain hit a historic energy milestone. On April 16, for the first time, the country’s electricity demand was met entirely by renewable energy sources - solar, wind, and hydro, during a weekday. It raises questions whether the outage was caused by a technical failure of this new renewable energy system.
While this achievement is noteworthy, it also exposes the fragility of a grid increasingly reliant on variable energy sources, especially solar, which can fluctuate dramatically with weather and atmospheric conditions.
Despite official explanations, some experts and observers remain skeptical. There were no solar flares or geomagnetic storms in the days leading up to the blackout, and solar activity had been relatively calm. Critics argue that while atmospheric disturbances may have played a role, they are not sufficient to explain such a widespread, synchronized failure.
Despite the fact that the blackout this time was probably not caused by solar flares or geomagnetic storms it has been proven that Earth’s magnetic shield is rapidly weakening, leaving us increasingly vulnerable to powerful solar storms. The magnetic north pole is accelerating toward Siberia, and the South Atlantic Anomaly continues to expand, ominous signs that a looming plasma event could bring consequences far beyond just technological disruption.
This has led to speculation that the blackout could have been intentional, possibly even a test run for handling future crises or threats to infrastructure.
Among the more controversial theories is the suggestion that this event might have involved the use of a graphite bomb, a non-lethal weapon designed to disable power grids. These devices disperse ultra-fine carbon filaments into high-voltage power lines, causing short circuits by creating conductive paths between lines. Such an attack would appear as a grid malfunction but could be devastating in scale.
Another controversial theory is that the outage has been caused by weather manipulation systems such as HAARP or the Ice Cube Neutrino observatory, constructed at the Amundsen–Scott South Pole Station in Antarctica.
Could this have been a covert drill or a demonstration of vulnerability? Some point to global forums, such as the World Government Summit, where figures like Klaus Schwab have warned about Black Swan: An unpredictable event that is beyond what is normally expected of a situation and has potentially severe consequences.
Whether the blackout was triggered by a rare natural event, a technical failure, or something more deliberate, it seems only a matter of time before we face a true Black Swan event. View the full article
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By European Space Agency
The European Space Agency's XMM-Newton is playing a crucial role in investigating the longest and most energetic bursts of X-rays seen from a newly awakened black hole. Watching this strange behaviour unfold in real time offers a unique opportunity to learn more about these powerful events and the mysterious behaviour of massive black holes.
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By NASA
Explore Hubble Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts e-Books Online Activities Lithographs Fact Sheets Posters Hubble on the NASA App Glossary More 35th Anniversary Online Activities 2 min read
Hubble Studies a Nearby Galaxy’s Star Formation
This NASA/ESA Hubble Space Telescope image features the picturesque spiral galaxy NGC 4941. ESA/Hubble & NASA, D. Thilker This NASA/ESA Hubble Space Telescope image features the picturesque spiral galaxy NGC 4941, which lies about 67 million light-years from Earth in the constellation Virgo (The Maiden). Because this galaxy is nearby, cosmically speaking, Hubble’s keen instruments are able to pick out exquisite details such as individual star clusters and filamentary clouds of gas and dust.
The data used to construct this image were collected as part of an observing program that investigates the star formation and stellar feedback cycle in nearby galaxies. As stars form in dense, cold clumps of gas, they begin to influence their surroundings. Stars heat and stir up the gas clouds in which they form through winds, starlight, and — eventually, for massive stars — by exploding as supernovae. These processes are collectively called stellar feedback, and they influence the rate at which a galaxy can form new stars.
As it turns out, stars aren’t the only entities providing feedback in NGC 4941. At the heart of this galaxy lies an active galactic nucleus: a supermassive black hole feasting on gas. As the black hole amasses gas from its surroundings, the gas swirls into a superheated disk that glows brightly at wavelengths across the electromagnetic spectrum. Similar to stars — but on a much, much larger scale — active galactic nuclei shape their surroundings through winds, radiation, and powerful jets, altering not only star formation but also the evolution of the galaxy as a whole.
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD
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Last Updated Apr 04, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Hubble Space Telescope Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Spiral Galaxies The Universe Keep Exploring Discover More Topics From Hubble
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Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
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