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By NASA
2 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Heather Seagren grew up near NASA’s Stennis Space Center and visited for field trips as a child. Now, as a financial management specialist, Seagren coordinates work trips for NASA employees at the south Mississippi NASA center. NASA/Danny Nowlin A leap of faith for Heather Seagren eight years ago brought the Gulf Coast native to something new, yet also returned her to a familiar place at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.
Following graduation from Pearl River Community College, Seagren worked as an office manager at a pediatric office. Seagren anticipated a full career in the medical field until an opportunity at the south Mississippi NASA center “kind of fell in my lap,” she said.
The NASA Shared Services Center, located at NASA Stennis, was hiring for its travel department, so Seagren applied.
“There are many different roles here, and my biggest thing was, do not second guess your decisions,” she said. “It was a big change for me, and I made the leap and ended up where I am today, even though it was a completely different career field.”
A new career field, yes, but not a new place. Seagren grew up in Pearlington, Mississippi, less than 10 miles from the nation’s largest propulsion test site. Her grandfather, Grover “Shu-Shu” Bennett, retired from NASA Stennis as a tugboat captain, helping to deliver rocket propellants along the site canal system to the test stands at NASA Stennis.
Just as her grandfather ensured the rocket engine fuel made it to its destination on time, Seagren does the same for NASA employees by coordinating travel plans. She now is in a similar role as a NASA Stennis financial management specialist.
Working with astronauts, engineers, and many other NASA employees, no two trips are alike, which is a part of the job Seagren enjoys.
What is similar is the trips coordinated by Seagren align with NASA’s mission to explore the secrets of the universe for the benefit of all.
The Kiln, Mississippi, resident plays a vital role in the NASA mission by bringing together the details of booking flights, arranging accommodations, and managing schedules.
“The best thing about working at NASA Stennis is getting to experience everything,” she said. “It is always interesting to see what other projects and duties everybody is doing. The process kind of starts with the travel department. … It is a small step, but we are involved, making sure everybody is where they need to be, when they need to be there, so, I think that is pretty cool.”
Learn more about the people who work at NASA Stennis View the full article
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By NASA
“Trying to do stellar observations from Earth is like trying to do birdwatching from the bottom of a lake.” James B. Odom, Hubble Program Manager 1983-1990.
The third servicing mission to the Hubble Space Telescope, placed in orbit in 1990, occurred during the STS-103 mission in December 1999. During the mission, originally planned for June 2000 but accelerated by six months following unexpected failures of the telescope’s attitude control gyroscopes, the astronauts restored the facility to full functionality. During their eight-day mission that featured the first space shuttle crew to spend Christmas in space, the seven-member U.S. and European crew rendezvoused with and captured Hubble, and four astronauts in rotating teams of two conducted three lengthy and complex spacewalks to service and upgrade the telescope. They redeployed the telescope with greater capabilities than ever before to continue its mission to help scientists unlock the secrets of the universe.
Schematic showing the Hubble Space Telescope’s major components. Workers inspect the Hubble Space Telescope’s 94-inch diameter primary mirror prior to assembly. Astronauts release the Hubble Space Telescope in April 1990 during the STS-31 mission. The discovery after the Hubble Space Telescope’s launch in 1990 that its primary mirror suffered from a flaw called spherical aberration disappointed scientists who could not obtain the sharp images they had expected. But thanks to the Hubble’s built-in feature of on-orbit servicing, NASA devised a plan to correct the telescope’s optics during the first planned repair mission in 1993. A second servicing mission in 1997 upgraded the telescope’s capabilities until the next mission planned for three years later. But after three of the telescope’s six gyroscopes failed in 1997, 1998, and 1999, mission rules dictated a call up mission in case additional gyroscope failures sent Hubble into a safe mode. NASA elected to move up some of the servicing tasks from the third mission, splitting it into missions 3A and 3B, planning to fly 3A in October 1999 on Discovery’s STS-103 mission primarily to replace the failed gyroscopes. Delays to the shuttle fleet resulting from anomalies during the launch of STS-93 in July 1993 slipped STS-103 first into November and ultimately into December. Technical issues with Discovery itself pushed the launch date to mid-December, and raised concerns about having a shuttle in orbit during the Y2K transition. Once the launch had slipped to Dec. 19, mission planners cut the mission from 10 to eight days, deleting one of the four spacewalks, to ensure a return before the end of the calendar year. The servicing mission couldn’t come soon enough, as a fourth gyroscope failed aboard Hubble in mid-November, with Discovery already poised on the launch pad to prepare for STS-103. Controllers placed Hubble in a safe mode until the astronauts arrived.
The STS-103 crew of C. Michael Foale, left, Claude Nicollier, Scott J. Kelly, Curtis L. Brown, Jean-François A. Clervoy, John M. Grunsfeld, and Steven L. Smith. The STS-103 crew patch. The mission patch for the Hubble Servicing Mission-3A. To execute the third Hubble Servicing Mission, in July 1998 NASA selected an experienced four-person team to carry out a record-breaking six spacewalks on the flight then planned for June 2000. The spacewalkers included Mission Specialists Steven L. Smith serving as payload commander, John M. Grunsfeld, C. Michael Foale, and European Space Agency (ESA) astronaut Claude Nicollier from Switzerland. The addition in March 1999 of Commander Curtis L. Brown, Pilot Scott J. Kelly, and Mission Specialist ESA astronaut Jean-François A. Clervoy of France rounded out the highly experienced crew with 18 previous spaceflights among them. Brown earned the distinction as only the fifth person to fly in space six times. For Kelly, STS-103 marked his first spaceflight. Smith, Clervoy, and Grunsfeld each had flown two previous missions, Foale four including a long-duration mission aboard Mir, and Nicollier three. Smith participated in three spacewalks during the second Hubble Servicing Mission and Nicollier served as the Remote Manipulator System (RMS) or robotic arm operator during the first.
The STS-103 crew at the traditional prelaunch breakfast at NASA’s Kennedy Space Center in Florida. Suited up, the STS-103 astronauts leave crew quarters for the trip to Launch Pad 39B. Space shuttle Discovery on Launch Pad 39B, awaiting launch. Discovery arrived back to KSC at the end of the STS-96 mission on June 6, 1999, and workers towed it to the Orbiter Processing Facility the same day to begin readying it for STS-103. The vehicle rolled over to the Vehicle Assembly Building on Nov. 4, where workers mated it with its external tank and twin solid rocket boosters, before rolling the stack out to Launch Pad 39B on Nov. 13.
Liftoff of space shuttle Discovery on the STS-103 Hubble Space Telescope servicing mission 3A. The Hubble Space Telescope as Discovery approaches. The STS-103 crew berthing the Hubble into the payload bay. Beginning its 27th trip into space, Discovery lifted off from Launch Pad 39B at 7:50 p.m. EST on Dec. 19 to fix the ailing space telescope. Two days later, Brown and Kelly maneuvered Discovery to within range of Hubble so Clervoy operating the 50-foot-long RMS could grapple the telescope and berth it into the payload bay.
During the first spacewalk, astronauts John M. Grunsfeld, left, and Steven L. Smith replacing one of the Rate Sensor Units containing two gyroscopes. Smith gives a thumbs up with his image reflected in the Hubble Space Telescope. Smith and Grunsfeld conducted the mission’s first spacewalk on Dec. 22, the flight’s fourth day in space. The duo, aided by Clervoy operating the RMS from inside Discovery, completed two of mission’s highest priority objectives. They replaced the failed gyroscopes, installing three new Rate Sensor Units, each containing two gyroscopes, to return control to the ailing telescope. They also installed six Voltage/Temperature Improvement Kits to prevent the telescope’s batteries from overheating as they aged. The excursion lasted eight hours 15 minutes, at the time the second longest spacewalk.
During the second spacewalk, astronauts C. Michael Foale, left, and Claude Nicollier during the changeout of the fine guidance sensor. Foale at the end of the Remote Manipulator System services the Hubble Space Telescope. The next day, Nicollier and Foale conducted the mission’s second spacewalk. The main task for this excursion involved installing a new computer aboard Hubble, replacing the original 1970s vintage unit. The new radiation-hardened system ran 20 times faster and carried six times more memory while using one-third the electrical power. They also installed a fine guidance sensor before concluding the eight-hour 10-minute spacewalk.
Astronauts Steven L. Smith, left, and John M. Grunsfeld begin their servicing activities during the third spacewalk. At the end of the third and final spacewalk, Grunsfeld, left, and Smith provide closing comments about the work the mission accomplished to service the Hubble Space Telescope. Smith and Grunsfeld ventured outside for a second time to complete the flight’s third and final spacewalk on Dec. 24, the first spacewalk conducted on Christmas Eve day. First, they replaced an old reel-to-reel tape recorder with a solid state unit providing a 10-fold increase in recording capability and replaced a failed data transmitter. They installed seven new covers on Hubble’s electronics bay doors for added protection of the telescope’s insulation. This third spacewalk lasted eight hours eight minutes.
The first space shuttle crew to celebrate Christmas in space, the STS-103 astronauts pose wearing Santa hats. The Hubble Space Telescope shortly after the STS-103 crew released it. The next day, the STS-103 astronauts earned the distinction as the first space shuttle crew to spend Christmas Day in space. Clervoy grappled Hubble, lifted it out of the payload bay and released it to continue its mission. Hubble Space Telescope Program Manager John H. Campbell said after the release, “The spacecraft is being guided by its new gyros under the control of its brand new computer. [It] is now orbiting freely and is in fantastic shape.” After deploying Hubble, the astronauts enjoyed a well-deserved Christmas dinner, with Clervoy providing French delicacies. The crew spent Dec. 26 readying Discovery for its return to Earth, including testing its reaction control system thrusters and aerodynamic surfaces and stowing unneeded gear.
Astronauts Steven L. Smith, left, Claude Nicollier, and John M. Grunsfeld complete their fluid loading protocol and put on their launch and entry suits prior to reentry. Space shuttle Discovery makes a perfect night landing at NASA’s Kennedy Space Center in Florida. The crew welcome home ceremony at Ellington Field in Houston. On Dec. 27, the astronauts donned their launch and entry suits and prepared for the return to Earth. They closed the payload bay doors and fired Discovery’s engines to bring them out of orbit. Just before landing, Kelly lowered the craft’s landing gear and Brown guided Discovery to a smooth night landing at KSC, concluding a flight of seven days, 23 hours, 11 minutes. They circled the Earth 119 times. The flight marked Discovery’s last solo flight as all its subsequent missions docked with the International Space Station. Workers at KSC began readying it for its next mission, STS-92 in October 2000.
The Hubble Space Telescope continues to operate today, far exceeding the five-year life extension expected from the last of the servicing missions in 2009. Joined in space by the James Webb Space Telescope in 2021, the two instruments together continue to image the skies across a broad range of the electromagnetic spectrum to provide scientists with the tools to gain unprecedented insights into the universe and its formation.
Watch the STS-103 crew narrate a video of their Hubble servicing mission.
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By NASA
5 Min Read NASA DAVINCI Mission’s Many ‘Firsts’ to Unlock Venus’ Hidden Secrets
The surface of Venus is an inferno with temperatures hot enough to melt lead. This image is a composite of data from NASA’s Magellan spacecraft and Pioneer Venus Orbiter. Credits:
NASA/JPL-Caltech NASA’s DAVINCI — Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging — mission embodies the spirit of innovation and exploration that its namesake, Leonardo da Vinci, was famous for.
Scheduled to launch in the early 2030s, DAVINCI will explore Venus with both a spacecraft and a descent probe. DAVINCI’s probe will be the first in the 21st century to brave Venus’ atmosphere as it descends from above the planet’s clouds down to its surface. Two other missions, NASA’s VERITAS and ESA’s (European Space Agency) Envision, will also explore Venus in the 2030s from the planet’s orbit.
The DAVINCI spacecraft will study Venus’ clouds and highlands during two flybys. It also will release a spherical probe, about 3 feet wide, that will plunge through the planet’s thick atmosphere and corrosive clouds, taking measurements and capturing high-resolution images of the Venusian surface as it descends below the clouds.
Here are some of DAVINCI’s coming “firsts” in Venus exploration:
Exploring Solar System’s One-of-a-Kind Terrain
The DAVINCI mission will be the first to closely explore Alpha Regio, a region known as a “tessera.” So far found only on Venus, where they make up about 8% of the surface, tesserae are highland regions similar in appearance to rugged mountains on Earth. Previous missions discovered these features using radar instruments, but of the many international spacecraft that dove through Venus’ atmosphere between 1966 and 1985, none studied or photographed tesserae.
Thought to be ancient continents, tesserae like Alpha Regio may be among the oldest surfaces on the planet, offering scientists access to rocks that are billions of years old.
By studying these rocks from above Alpha Regio, DAVINCI scientists may learn whether ancient Venus had continents and oceans, and how water may have influenced the surface.
Photographing One of the Oldest Surfaces on Venus
The DAVINCI probe will capture the first close-up views of Alpha Regio with its infrared and optical cameras; these will also be the first photos of the planet’s surface taken in more than 40 years.
With surface temperatures reaching 900° F and air pressure 90 times that of Earth’s, Venus’ harsh environment makes exploration challenging, while its opaque atmosphere obscures direct views. Typically, scientists rely on radar instruments from Earth or Venus-orbiting spacecraft to study its terrain.
But DAVINCI’s probe will descend through the atmosphere and below the clouds for a clear view of the mountains and plains. It will capture images comparable to an airplane’s landing view of Earth’s surface. Scientists will use the photos to compile 3D maps of Alpha Regio that will provide more detail than ever of Venus’ terrain, helping them look for rocks that are usually only made in association with water.
Unveiling Secrets of Venus’ Mysterious Lower Atmosphere
The DAVINCI mission will be the first to analyze the chemical composition of Venus’ lower atmosphere through measurements taken at regular intervals, starting from approximately 90,000 feet above the surface and continuing until just before impact.
This region is critical because it contains gases and chemical compounds that may originate from Venus’ lower clouds, surface, or even subsurface.
For example, sulfur compounds detected here could indicate whether Venusian volcanoes are currently active or were active in the recent past. Noble gases (like helium or xenon), on the other hand, remain chemically inert and maintain stable concentrations, offering invaluable clues about Venus’ ancient history, such as the planet’s past water inventory.
By comparing Venus’ noble gas composition with that of Earth and Mars, scientists can better understand why these planets — despite forming from similar starting materials — evolved into dramatically different worlds.
Moreover, DAVINCI’s measurements of isotopes and trace gases in the lower atmosphere will shed light on Venus’ water history, from ancient times to the present, and the processes that triggered the planet’s extreme greenhouse effect.
State-of-the-Art Technology to Study Venus in Detail
Thanks to modern technology, the DAVINCI probe will be able to do things 1980s-era spacecraft couldn’t.
The descent probe will be better equipped than previous probes to protect the sensitive electronics inside of it, as it will be lined on the inside with high-temperature, multi-layer insulation — layers of advanced ceramic and silica fabrics separated by aluminum sheets.
Venus’ super thick atmosphere will slow the probe’s descent, but a parachute will also be released to slow it down further. Most Earth-friendly parachute fabrics, like nylon, would dissolve in Venus’ sulfuric acid clouds, so DAVINCI will have to use a different type of material than previous Venus missions did: one that’s resistant to acids and five times stronger than steel.
Read More: Old Data Yields New Secrets as NASA’s DAVINCI Preps for Venus Trip
By Lauren Colvin, with Lonnie Shekhtman
NASA’s Goddard Space Flight Center, Greenbelt, Md.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator institution for DAVINCI and will perform project management for the mission, provide science instruments, as well as project systems engineering to develop the in-situ probe flight system that will enter the atmosphere of Venus. Goddard also leads the overall science for the mission with an external science team from across the United States. Lockheed Martin Space in Denver, Colorado, will build the carrier/relay spacecraft. DAVINCI is a mission within the Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA’s IXPE (Imaging X-ray Polarimetry Explorer) has helped astronomers better understand the shapes of structures essential to a black hole – specifically, the disk of material swirling around it, and the shifting plasma region called the corona.
The stellar-mass black hole, part of the binary system Swift J1727.8-1613, was discovered in the summer of 2023 during an unusual brightening event that briefly caused it to outshine nearly all other X-ray sources. It is the first of its kind to be observed by IXPE as it goes through the start, peak, and conclusion of an X-ray outburst like this.
This illustration shows NASA’s Imaging X-ray Polarimetry Explorer (IXPE) spacecraft, at lower left, observing the newly discovered binary system Swift J1727.8-1613 from a distance. At the center is a black hole surrounded by an accretion disk, shown in yellow and orange, and a hot, shifting corona, shown in blue. The black hole is siphoning off gas from its companion star, seen behind the black hole as an orange disk. Jets of fast-moving, superheated particles stream from both poles of the black hole. Author: Marie Novotná Swift J1727 is the subject of a series of new studies published in The Astrophysical Journal and Astronomy & Astrophysics. Scientists say the findings provide new insight into the behavior and evolution of black hole X-ray binary systems.
“This outburst evolved incredibly quickly,” said astrophysicist Alexandra Veledina, a permanent researcher at the University of Turku, Finland. “From our first detection of the outburst, it took Swift J1727 just days to peak. By then, IXPE and numerous other telescopes and instruments were already collecting data. It was exhilarating to observe the outburst all the way through its return to inactivity.”
Until late 2023, Swift J1727 briefly remained brighter than the Crab Nebula, the standard X-ray “candle” used to provide a baseline for units of X-ray brightness. Such outbursts are not unusual among binary star systems, but rarely do they occur so brightly and so close to home – just 8,800 light years from Earth. The binary system was named in honor of the Swift Gamma-ray Burst Mission which initially detected the outburst with its Burst Alert Telescope on Aug. 24, 2023, resulting in the discovery of the black hole.
X-ray binary systems typically include two close-proximity stars at different stages of their lifecycle. When the elder star runs out of fuel, it explodes in a supernova, leaving behind a neutron star, white dwarf, or black hole. In the case of Swift J1727, the powerful gravity of the resulting black hole stripped material from its companion star, heating the material to more than 1.8 million degrees Fahrenheit and producing a vast outpouring of X-rays. This matter formed an accretion disk and can include a superheated corona. At the poles of the black hole, matter also can escape from the binary system in the form of relativistic jets.
IXPE, which has helped NASA and researchers study all these phenomena, specializes in X-ray polarization, the characteristic of light that helps map the shape and structure of such ultra-powerful energy sources, illuminating their inner workings even when they’re too distant for us to see directly.
Because light itself can’t escape their gravity, we can’t see black holes. We can only observe what is happening around them and draw conclusions about the mechanisms and processes that occur there. IXPE is crucial to that work.
/wp-content/plugins/nasa-blocks/assets/images/article-templates/anne-mcclain.jpg Alexandra Veledina
NASA Astrophysicist
“Because light itself can’t escape their gravity, we can’t see black holes,” Veledina said. “We can only observe what is happening around them and draw conclusions about the mechanisms and processes that occur there. IXPE is crucial to that work.”
Two of the IXPE-based studies of Swift J1727, led by Veledina and Adam Ingram, a researcher at Newcastle University in Newcastle-upon-Tyne, England, focused on the first phases of the outburst. During the brief period of months when the source became exceptionally bright, the corona was the main source of observed X-ray radiation.
“IXPE documented polarization of X-ray radiation traveling along the estimated direction of the black hole jet, hence the hot plasma is extended in the accretion disk plane,” Veledina said. “Similar findings were reported in the persistent black hole binary Cygnus X-1, so this finding helps verify that the geometry is the same among short-lived eruptive systems.”
The team further monitored how polarization values changed during Swift J1727’s peak outburst. Those conclusions matched findings simultaneously obtained during studies of other energy bands of electromagnetic radiation.
A third and a fourth study, led by researchers Jiří Svoboda and Jakub Podgorný, both of the Czech Academy of Sciences in Prague, focused on X-ray polarization at the second part of the Swift J1727’s outburst and its return to a highly energetic state several months later. For Podgorný’s previous efforts using IXPE data and black hole simulations, he recently was awarded the Czech Republic’s top national prize for a Ph.D. thesis in the natural sciences.
The polarization data indicated that the geometry of the corona did not change significantly between the beginning and the end of the outburst, even though the system evolved in the meantime and the X-ray brightness dropped dramatically in the later energetic state.
The results represent a significant step forward in our understanding of the changing shapes and structures of accretion disk, corona, and related structures at black holes in general. The study also demonstrates IXPE’s value as a tool for determining how all these elements of the system are connected, as well as its potential to collaborate with other observatories to monitor sudden, dramatic changes in the cosmos.
“Further observations of matter near black holes in binary systems are needed, but the successful first observing campaign of Swift J1727.8–1613 in different states is the best start of a new chapter we could imagine,” said Michal Dovčiak, co-author of the series of papers and leader of the IXPE working group on stellar-mass black holes, who also conducts research at the Czech Academy of Sciences.
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. 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 Dec 06, 2024 Related Terms
IXPE (Imaging X-ray Polarimetry Explorer) Marshall Science Research & Projects Marshall Space Flight Center Explore More
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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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