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NASA’s Juno Finds Jupiter’s Winds Penetrate in Cylindrical Layers
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By NASA
4 min read
NASA’s Fermi Finds New Feature in Brightest Gamma-Ray Burst Yet Seen
In October 2022, astronomers were stunned by what was quickly dubbed the BOAT — the brightest-of-all-time gamma-ray burst (GRB). Now an international science team reports that data from NASA’s Fermi Gamma-ray Space Telescope reveals a feature never seen before.
The brightest gamma-ray burst yet recorded gave scientists a new high-energy feature to study. Learn what NASA’s Fermi mission saw, and what this feature may be telling us about the burst’s light-speed jets. Credit: NASA’s Goddard Space Flight Center
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“A few minutes after the BOAT erupted, Fermi’s Gamma-ray Burst Monitor recorded an unusual energy peak that caught our attention,” said lead researcher Maria Edvige Ravasio at Radboud University in Nijmegen, Netherlands, and affiliated with Brera Observatory, part of INAF (the Italian National Institute of Astrophysics) in Merate, Italy. “When I first saw that signal, it gave me goosebumps. Our analysis since then shows it to be the first high-confidence emission line ever seen in 50 years of studying GRBs.”
A paper about the discovery appears in the July 26 edition of the journal Science.
When matter interacts with light, the energy can be absorbed and reemitted in characteristic ways. These interactions can brighten or dim particular colors (or energies), producing key features visible when the light is spread out, rainbow-like, in a spectrum. These features can reveal a wealth of information, such as the chemical elements involved in the interaction. At higher energies, spectral features can uncover specific particle processes, such as matter and antimatter annihilating to produce gamma rays.
“While some previous studies have reported possible evidence for absorption and emission features in other GRBs, subsequent scrutiny revealed that all of these could just be statistical fluctuations. What we see in the BOAT is different,” said coauthor Om Sharan Salafia at INAF-Brera Observatory in Milan, Italy. “We’ve determined that the odds this feature is just a noise fluctuation are less than one chance in half a billion.”
A jet of particles moving at nearly light speed emerges from a massive star in this artist’s concept. The star’s core ran out of fuel and collapsed into a black hole. Some of the matter swirling toward the black hole was redirected into dual jets firing in opposite directions. We see a gamma-ray burst when one of these jets happens to point directly at Earth. NASA’s Goddard Space Flight Center Conceptual Image Lab GRBs are the most powerful explosions in the cosmos and emit copious amounts of gamma rays, the highest-energy form of light. The most common type occurs when the core of a massive star exhausts its fuel, collapses, and forms a rapidly spinning black hole. Matter falling into the black hole powers oppositely directed particle jets that blast through the star’s outer layers at nearly the speed of light. We detect GRBs when one of these jets points almost directly toward Earth.
The BOAT, formally known as GRB 221009A, erupted Oct. 9, 2022, and promptly saturated most of the gamma-ray detectors in orbit, including those on Fermi. This prevented them from measuring the most intense part of the blast. Reconstructed observations, coupled with statistical arguments, suggest the BOAT, if part of the same population as previously detected GRBs, was likely the brightest burst to appear in Earth’s skies in 10,000 years.
The putative emission line appears almost 5 minutes after the burst was detected and well after it had dimmed enough to end saturation effects for Fermi. The line persisted for at least 40 seconds, and the emission reached a peak energy of about 12 MeV (million electron volts). For comparison, the energy of visible light ranges from 2 to 3 electron volts.
So what produced this spectral feature? The team thinks the most likely source is the annihilation of electrons and their antimatter counterparts, positrons.
“When an electron and a positron collide, they annihilate, producing a pair of gamma rays with an energy of 0.511 MeV,” said coauthor Gor Oganesyan at Gran Sasso Science Institute and Gran Sasso National Laboratory in L’Aquila, Italy. “Because we’re looking into the jet, where matter is moving at near light speed, this emission becomes greatly blueshifted and pushed toward much higher energies.”
If this interpretation is correct, to produce an emission line peaking at 12 MeV, the annihilating particles had to have been moving toward us at about 99.9% the speed of light.
“After decades of studying these incredible cosmic explosions, we still don’t understand the details of how these jets work,” noted Elizabeth Hays, the Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Finding clues like this remarkable emission line will help scientists investigate this extreme environment more deeply.”
The Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership managed by Goddard. Fermi was developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the United States.
By Francis Reddy
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media Contact:
Claire Andreoli
301-286-1940
claire.andreoli@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Jul 25, 2024 Related Terms
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By NASA
Image data: NASA/JPL-Caltech/SwRI/MSSS
Image processing by Gary Eason © CC BY During its 61st close flyby of Jupiter on May 12, 2024, NASA’s Juno spacecraft captured this color-enhanced view of the giant planet’s northern hemisphere. It provides a detailed view of chaotic clouds and cyclonic storms in an area known to scientists as a folded filamentary region. In these regions, the zonal jets that create the familiar banded patterns in Jupiter’s clouds break down, leading to turbulent patterns and cloud structures that rapidly evolve over the course of only a few days.
Citizen scientist Gary Eason made this image using raw data from the JunoCam instrument, applying digital processing techniques to enhance color and clarity.
At the time the raw image was taken, the Juno spacecraft was about 18,000 miles (29,000 kilometers) above Jupiter’s cloud tops, at a latitude of about 68 degrees north of the equator.
JunoCam’s raw images are available for the public to peruse and process into image products at https://missionjuno.swri.edu/junocam/processing. More information about NASA citizen science can be found at https://science.nasa.gov/citizenscience and https://www.nasa.gov/solve/opportunities/citizenscience.
More information about Juno is at https://www.nasa.gov/juno and https://missionjuno.swri.edu. For more about this finding and other science results, see https://www.missionjuno.swri.edu/science-findings.
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By NASA
4 Min Read NASA’s Hubble Finds Strong Evidence for Intermediate-Mass Black Hole in Omega Centauri
This NASA Hubble Space Telescope image features the globular star cluster, Omega Centauri. Credits:
ESA/Hubble, NASA, Maximilian Häberle (MPIA) Most known black holes are either extremely massive, like the supermassive black holes that lie at the cores of large galaxies, or relatively lightweight, with a mass of under 100 times that of the Sun. Intermediate-mass black holes (IMBHs) are scarce, however, and are considered rare “missing links” in black hole evolution.
Now, an international team of astronomers has used more than 500 images from NASA’s Hubble Space Telescope — spanning two decades of observations — to search for evidence of an intermediate-mass black hole by following the motion of seven fast-moving stars in the innermost region of the globular star cluster Omega Centauri.
Omega Centauri is about 10 times as massive as other big globular clusters – almost as massive as a small galaxy – and consists of roughly 10 million stars that are gravitationally bound. ESA/Hubble, NASA, Maximilian Häberle (MPIA)
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These stars provide new compelling evidence for the presence of the gravitational pull from an intermediate-mass black hole tugging on them. Only a few other IMBH candidates have been found to date.
Omega Centauri consists of roughly 10 million stars that are gravitationally bound. The cluster is about 10 times as massive as other big globular clusters — almost as massive as a small galaxy.
Among the many questions scientists want to answer: Are there any IMBHs, and if so, how common are they? Does a supermassive black hole grow from an IMBH? How do IMBHs themselves form? Are dense star clusters their favored home?
The astronomers have now created an enormous catalog for the motions of these stars, measuring the velocities for 1.4 million stars gleaned from the Hubble images of the cluster. Most of these observations were intended to calibrate Hubble’s instruments rather than for scientific use, but they turned out to be an ideal database for the team’s research efforts.
This image shows the central region of the Omega Centauri globular cluster, where NASA’s Hubble Space Telescope found strong evidence for an intermediate-mass black hole candidate. ESA/Hubble, NASA, Maximilian Häberle (MPIA)
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“We discovered seven stars that should not be there,” explained Maximilian Häberle of the Max Planck Institute for Astronomy in Germany, who led this investigation. “They are moving so fast that they would escape the cluster and never come back. The most likely explanation is that a very massive object is gravitationally pulling on these stars and keeping them close to the center. The only object that can be so massive is a black hole, with a mass at least 8,200 times that of our Sun.”
Several studies have suggested the presence of an IMBH in Omega Centauri. However, other studies proposed the mass could be contributed by a central cluster of stellar-mass black holes, and had suggested the lack of fast-moving stars above the necessary escape velocity made an IMBH less likely in comparison.
An international team of astronomers used more than 500 images from NASA’s Hubble Space Telescope – spanning two decades of observations – to detect seven fast-moving stars in the innermost region of Omega Centauri, the largest and brightest globular cluster in the sky. These stars provide compelling new evidence for the presence of an intermediate-mass black hole (IMBH) tugging on them. Only a few other IMBH candidates have been found to date. This image shows the location of the IMBH in Omega Centauri. If confirmed, at its distance of 17,700 light-years the candidate black hole resides closer to Earth than the 4.3-million-solar-mass black hole in the center of the Milky Way, which is 26,000 light-years away. Besides the Galactic center, it would also be the only known case of a number of stars closely bound to a massive black hole. This image includes three panels. The first image at left shows the globular cluster Omega Centauri, a collection of myriad stars colored red, white, and blue on the black background of space. The second image shows the details of the central region of this cluster, with a closer view of the individual stars. The third image shows the location of the IMBH candidate in the cluster. ESA/Hubble, NASA, Maximilian Häberle (MPIA)
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“This discovery is the most direct evidence so far of an IMBH in Omega Centauri,” added team lead Nadine Neumayer of the Max Planck Institute for Astronomy in Germany, who initiated the study, together with Anil Seth from the University of Utah, Salt Lake City. “This is exciting because there are only very few other black holes known with a similar mass. The black hole in Omega Centauri may be the best example of an IMBH in our cosmic neighborhood.”
If confirmed, at a distance of 17,700 light-years the candidate black hole resides closer to Earth than the 4.3-million-solar-mass black hole in the center of the Milky Way, located 26,000 light-years away.
Omega Centauri is visible from Earth with the naked eye and is one of the favorite celestial objects for stargazers living in the southern hemisphere. Located just above the plane of the Milky Way, the cluster appears almost as large as the full Moon when seen from a dark rural area. It was first listed in Ptolemy’s catalog nearly 2,000 years ago as a single star. Edmond Halley reported it as a nebula in 1677. In the 1830s the English astronomer John Herschel was the first to recognize it as a globular cluster.
The discovery paper led by Häberle et al. is published online today in the journal Nature.
Scientists think a massive object is gravitationally pulling on the stars within Omega Centauri, keeping them close to its center. Credit: NASA’s Goddard Space Flight Center, Lead Producer: Paul Morris
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The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contacts:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Space Telescope Science Institute, Baltimore, MD
Bethany Downer
ESA/Hubble.org
Science Contact:
Maximilian Häberle
Max Planck Institute for Astronomy, Heidelberg, Germany
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Last Updated Jul 10, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
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Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
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By European Space Agency
An international team of astronomers has used more than 500 images from the NASA/ESA Hubble Space Telescope spanning two decades to detect seven fast-moving stars in the innermost region of Omega Centauri, the largest and brightest globular cluster in the sky. These stars provide compelling new evidence for the presence of an intermediate-mass black hole.
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By NASA
5 min read
Alphabet Soup: NASA’s GOLD Finds Surprising C, X Shapes in Atmosphere
Who knew Earth’s upper atmosphere was like alphabet soup?
NASA’s Global-scale Observations of the Limb and Disk (GOLD) mission has revealed unexpected C- and X-shaped formations in an electrified layer of gas high above our heads called the ionosphere.
While these alphabetical shapes have been observed before, GOLD sees them more clearly than other instruments have and is now finding them where and when scientists didn’t expect. Their surprise appearances prove that we have more to learn about the ionosphere and its effects on communication and navigation signals that pass through it.
Earth’s Dynamic Interface to Space
Extending some 50 to 400 miles overhead, the ionosphere becomes electrically charged during the daytime when sunlight strikes our planet and its energy knocks electrons off atoms and molecules. This creates a soup of charged particles, known as plasma, that allows radio signals to travel over long distances.
Near Earth’s magnetic equator, charged particles are funneled upward and outward along magnetic field lines, creating two dense bands of particles north and south of the equator that scientists call crests. As night falls and the Sun’s energy fades, low-density pockets in the plasma, called bubbles, can form in the ionosphere. Because of their varying density, the crests and bubbles can interfere with radio and GPS signals.
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Under the combined influence of gravity and Earth’s electric and magnetic fields, charged particles in the ionosphere flow upward and outward away from Earth’s magnetic equator, forming two dense bands, or crests, to the north and south of the equator. Learn more here. NASA’s Scientific Visualization Studio While previous observations provided brief glimpses of crests and bubbles in the ionosphere, GOLD monitors these features over extended periods of time. That’s thanks to its geostationary orbit, which circles our planet at the same rate Earth rotates, allowing GOLD to hover over the Western Hemisphere.
Unexpected X-Shaped Crests from Quiet Conditions
The ionosphere is sensitive to disturbances from both space and terrestrial weather. GOLD has previously revealed that after a solar storm or huge volcanic eruption, the crests in the ionosphere can merge to form an X shape. But now, GOLD has seen an X shape form on multiple occasions when there were no such disturbances — what scientists refer to as “quiet time.”
“Earlier reports of merging were only during geomagnetically disturbed conditions — it is an unexpected feature during geomagnetic quiet conditions,” said Fazlul Laskar, of the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP), who is the lead author of a paper about this discovery published in April 2024 by the Journal of Geophysical Research: Space Physics.
Observations from NASA’s GOLD mission shows charged particles in the ionosphere forming an X shape on Oct. 7, 2019. (The colors indicate the intensity of the ultraviolet light emitted, with yellow and white indicating the strongest emission, or highest ionospheric density.) F. Laskar et al. These unexpected appearances tell scientists that something else must be involved in forming these X shapes. Computer models suggest that the X could develop when changes in the lower atmosphere pull plasma downward.
“The X is odd because it implies that there are far more localized driving factors,” said Jeffrey Klenzing, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who studies the ionosphere. “This is expected during the extreme events, but seeing it during ‘quiet time’ suggests that the lower atmosphere activity is significantly driving the ionospheric structure.”
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This visualization shows a bright, horizontal X-shaped feature appearing in the ionosphere on Oct. 7, 2019, as observed by NASA’s GOLD mission. Each of GOLD’s observations cover about 45 degrees in longitude and proceed from east to west, alternating between the Northern and Southern hemispheres. Rayleigh is a unit for measuring the amount of light (in this case, ultraviolet light). NASA’s Scientific Visualization Studio C-Shaped Bubbles Point to Strong Turbulence
GOLD has also found surprising C-shaped plasma bubbles that point to other puzzling dynamics influencing the ionosphere.
Most plasma bubbles appear long and straight, forming along magnetic field lines. But some bubbles are curved into C shapes and reverse-C shapes, which scientists think are shaped by terrestrial winds. Computer models suggest a C-shape forms if winds increase with altitude at the magnetic equator and a reverse-C forms if the winds decrease with altitude.
“It’s a little like a tree growing in a windy area,” explains Klenzing. “If the winds are typically to the east, the tree starts to tilt and grow in that direction.”
In a paper published in November 2023 in the Journal of Geophysical Research: Space Physics, LASP scientist Deepak Karan and colleagues report that GOLD has observed C-shaped and reverse-C-shaped plasma bubbles appearing surprisingly close together — as close as about 400 miles apart (roughly the distance between Baltimore and Boston).
Images from NASA’s GOLD mission show C-shaped and reverse-C-shaped plasma bubbles appearing close together in the ionosphere on Oct. 12, 2020, and Dec. 26, 2021. D. Karan et al. “Within that close proximity, these two opposite-shaped plasma bubbles had never been thought of, never been imaged,” said Karan. To have wind patterns change course in such a small area, Karan thinks some sort of strong turbulence — like a vortex, wind shear, or tornado-like activity — is likely at play in the atmosphere.
“The fact that we have very different shapes of bubbles this close together tells us that the dynamics of the atmosphere is more complex than we expected,” Klenzing said.
These close pairings appear to be rare, with only two instances recorded by GOLD so far. Yet because these features can disrupt critical communication and navigation technology, “It’s really important to find out why this is happening,” Karan said. “If a vortex or a very strong shear in the plasma has happened, this will completely distort the plasma over that region. Signals will be lost completely with a strong disturbance like this.”
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This visualization shows C-shaped and reverse-C-shaped plasma bubbles appearing close together in the ionosphere on Oct. 12, 2020, and Dec. 26, 2021, as observed by NASA’s GOLD mission. The bubbles appear as dark blue vertical features extending between two bright (dense) crests. NASA’s Scientific Visualization Studio Scientists hope GOLD’s continued observations, combined with those from other heliophysics missions, can help unlock these mysteries of the ionosphere and their effects on our lives.
By Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Jun 27, 2024 Related Terms
Earth’s Atmosphere Goddard Space Flight Center GOLD (Global-scale Observations of the Limb and Disk) Heliophysics Ionosphere The Sun Explore More
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