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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
New findings using data from NASA’s IXPE (Imaging X-ray Polarimetry Explorer) mission offer unprecedented insight into the shape and nature of a structure important to black holes called a corona.
A corona is a shifting plasma region that is part of the flow of matter onto a black hole, about which scientists have only a theoretical understanding. The new results reveal the corona’s shape for the first time, and may aid scientists’ understanding of the corona’s role in feeding and sustaining black holes.
This illustration of material swirling around a black hole highlights a particular feature, called the “corona,” that shines brightly in X-ray light. In this depiction, the corona can be seen as a purple haze floating above the underlying accretion disk, and extending slightly inside of its inner edge. The material within the inner accretion disk is incredibly hot and would glow with a blinding blue-white light, but here has been reduced in brightness to make the corona stand out with better contrast. Its purple color is purely illustrative, standing in for the X-ray glow that would not be obvious in visible light. The warp in the disk is a realistic representation of how the black hole’s immense gravity acts like an optical lens, distorting our view of the flat disk that encircles it. NASA/Caltech-IPAC/Robert Hurt Many black holes, so named because not even light can escape their titanic gravity, are surrounded by accretion disks, debris-cluttered whirlpools of gas. Some black holes also have relativistic jets – ultra-powerful outbursts of matter hurled into space at high speed by black holes that are actively eating material in their surroundings.
Less well known, perhaps, is that snacking black holes, much like Earth’s Sun and other stars, also possess a superheated corona. While the Sun’s corona, which is the star’s outermost atmosphere, burns at roughly 1.8 million degrees Fahrenheit, the temperature of a black hole corona is estimated at billions of degrees.
Astrophysicists previously identified coronae among stellar-mass black holes – those formed by a star’s collapse – and supermassive black holes such as the one at the heart of the Milky Way galaxy.
“Scientists have long speculated on the makeup and geometry of the corona,” said Lynne Saade, a postdoctoral researcher at NASA’s Marshall Space Flight Center in Huntsville, Alabama, and lead author of the new findings. “Is it a sphere above and below the black hole, or an atmosphere generated by the accretion disk, or perhaps plasma located at the base of the jets?”
Enter IXPE, which specializes in X-ray polarization, the characteristic of light that helps map the shape and structure of even the most powerful energy sources, illuminating their inner workings even when the objects are too small, bright, or distant to see directly. Just as we can safely observe the Sun’s corona during a total solar eclipse, IXPE provides the means to clearly study the black hole’s accretion geometry, or the shape and structure of its accretion disk and related structures, including the corona.
“X-ray polarization provides a new way to examine black hole accretion geometry,” Saade said. “If the accretion geometry of black holes is similar regardless of mass, we expect the same to be true of their polarization properties.”
IXPE demonstrated that, among all black holes for which coronal properties could be directly measured via polarization, the corona was found to be extended in the same direction as the accretion disk – providing, for the first time, clues to the corona’s shape and clear evidence of its relationship to the accretion disk. The results rule out the possibility that the corona is shaped like a lamppost hovering over the disk.
The research team studied data from IXPE’s observations of 12 black holes, among them Cygnus X-1 and Cygnus X-3, stellar-mass binary black hole systems about 7,000 and 37,000 light-years from Earth, respectively, and LMC X-1 and LMC X-3, stellar-mass black holes in the Large Magellanic Cloud more than 165,000 light-years away. IXPE also observed a number of supermassive black holes, including the one at the center of the Circinus galaxy, 13 million light-years from Earth, and those in galaxies NGC 1068 and NGC 4151, 47 million light-years away and nearly 62 million light-years away, respectively.
Stellar mass black holes typically have a mass roughly 10 to 30 times that of Earth’s Sun, whereas supermassive black holes may have a mass that is millions to tens of billions of times larger. Despite these vast differences in scale, IXPE data suggests both types of black holes create accretion disks of similar geometry.
That’s surprising, said Marshall astrophysicist Philip Kaaret, principal investigator for the IXPE mission, because the way the two types are fed is completely different.
“Stellar-mass black holes rip mass from their companion stars, whereas supermassive black holes devour everything around them,” he said. “Yet the accretion mechanism functions much the same way.”
That’s an exciting prospect, Saade said, because it suggests that studies of stellar-mass black holes – typically much closer to Earth than their much more massive cousins – can help shed new light on properties of supermassive black holes as well.
The team next hopes to make additional examinations of both types.
Saade anticipates there’s much more to glean from X-ray studies of these behemoths. “IXPE has provided the first opportunity in a long time for X-ray astronomy to reveal the underlying processes of accretion and unlock new findings about black holes,” she said.
The complete findings are available in the latest issue of The Astrophysical Journal.
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 Marshall. Ball Aerospace, headquartered in Broomfield, Colorado, 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
NASA’s Marshall Space Flight Center
256-544-0034
lane.e.figueroa@nasa.gov
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Last Updated Oct 17, 2024 EditorBeth RidgewayLocationMarshall Space Flight Center Related Terms
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By European Space Agency
Video: 00:01:27 The ESA-led Solar Orbiter mission has experienced its second close encounter with the Sun. It is delivering more stunning data, and at higher resolution than ever before.
The moment of closest approach took place on 12 October at 19:12 UTC (21:12 CEST), when Solar Orbiter was just 29% of the Earth’s distance from the Sun. This movie comes from 13 October, when the spacecraft’s Extreme Ultraviolet Imager (EUI) returned the highest resolution movie of the quiet corona ever taken with any instrument.
Each pixel on this movie spans 105 km on the surface of the Sun. This means that if EUI were to look at the Earth from this distance, our entire planet would span just 120 pixels across. The movie itself contains 2048 across, meaning that 17 Earths would fit side by side across this image.
The corona is the Sun’s outer atmosphere. It is termed quiet when there is little appreciable solar activity such as flares or coronal mass ejections. This movie, and others taken during the encounter, show the dynamic nature of the Sun's million degree-hot corona. The electrically charged gas here, known as plasma, is in constant motion, guided and accelerated by changes of the Sun's magnetic field. The arches of bright plasma in the movie are being held in place by loops of magnetism that burst up into the corona from the Sun’s interior.
The Sun is currently ramping up for a peak in its activity levels, known as solar maximum, in 2025. So views of a quiet corona are likely to become rarer in the coming few years.
The Sun launches a solar wind of particles that streams out through the Solar System. It originates in the corona but the precise mechanism by which this happens is poorly understood. Investigating this phenomenon is a key focus for solar physicists, and one of Solar Orbiter’s main scientific objectives.
This particular encounter benefited from Solar Orbiter rapidly flying in the direction of Earth. This allowed much more data to be downlinked. It also allowed for coordinated observations of solar features to be made with Earth-based telescopes, from 21 October onwards.
“I am very much looking forward to data from all ten instruments being downloaded during the next few weeks, and then the world-wide science community will be very busy discovering new things using this unique data set,” says Daniel Müller, ESA Project Scientist for Solar Orbiter.
Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.
This movie was enhanced with Wavelet Optimized Whitening technique.
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By USH
Parker Solar Probe launched in 2018 to explore the mysteries of the Sun by traveling closer to it than any spacecraft before. Three years after launch and decades after first conception, Parker has finally arrived.
For the first time in history, a spacecraft has touched the Sun. NASA’s Parker Solar Probe has now flown through the Sun’s upper atmosphere – the corona – and sampled particles and magnetic fields there.
As Parker Solar Probe passed through the Sun's corona, the spacecraft flew by structures called coronal streamers. These structures can be seen as bright features moving upward and downward in the first video compiled from the spacecraft's WISPR (Wide-field Imager for Parker Solar Probe) instrument.
Such a view is only possible because the spacecraft flew above and below the streamers inside the corona. Until now, streamers have only been seen from afar. They are visible from Earth during total solar eclipses.
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By HubbleSite
A team of astronomers led by the University of Arizona has directly imaged with the SPHERE instrument on ESO's Very Large Telescope the first planet ever found in a wide orbit inside a triple-star system. The orbit of such a planet had been expected to be unstable, probably resulting in the planet being quickly ejected from the system. But somehow this one survives. This observation of the HD 131399 system suggests that such systems may actually be more common than previously thought. The results will be published online in the journal Science on July 7, 2016. The artist's impression shows a view of the triple-star system HD 131399 from the giant planet orbiting the system. The planet is HD 131399Ab and appears at the lower left of the picture.
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