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By NASA
NASA, ESA, and M. Wong (University of California – Berkeley); Processing: Gladys Kober (NASA/Catholic University of America) This NASA Hubble Space Telescope image shows the planet Jupiter in a color composite of ultraviolet wavelengths. Released on Nov. 3, 2023, in honor of Jupiter reaching opposition, which occurs when the planet and the Sun are in opposite sides of the sky, this view of the gas giant planet includes the iconic, massive storm called the “Great Red Spot.” Though the storm appears red to the human eye, in this ultraviolet image it appears darker because high altitude haze particles absorb light at these wavelengths. The reddish, wavy polar hazes are absorbing slightly less of this light due to differences in either particle size, composition, or altitude.
Learn more about Hubble and how this type of data can help us learn more about our universe.
Image credit: NASA, ESA, and M. Wong (University of California – Berkeley); Processing: Gladys Kober (NASA/Catholic University of America)
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By NASA
International teams of astronomers monitoring a supermassive black hole in the heart of a distant galaxy have detected features never seen before using data from NASA missions and other facilities. The features include the launch of a plasma jet moving at nearly one-third the speed of light and unusual, rapid X-ray fluctuations likely arising from near the very edge of the black hole.
Radio images of 1ES 1927+654 reveal emerging structures that appear to be jets of plasma erupting from both sides of the galaxy’s central black hole following a strong radio flare. The first image, taken in June 2023, shows no sign of the jet, possibly because hot gas screened it from view. Then, starting in February 2024, the features emerge and expand away from the galaxy’s center, covering a total distance of about half a light-year as measured from the center of each structure. NSF/AUI/NSF NRAO/Meyer at al. 2025 The source is 1ES 1927+654, a galaxy located about 270 million light-years away in the constellation Draco. It harbors a central black hole with a mass equivalent to about 1.4 million Suns.
“In 2018, the black hole began changing its properties right before our eyes, with a major optical, ultraviolet, and X-ray outburst,” said Eileen Meyer, an associate professor at UMBC (University of Maryland Baltimore County). “Many teams have been keeping a close eye on it ever since.”
She presented her team’s findings at the 245th meeting of the American Astronomical Society in National Harbor, Maryland. A paper led by Meyer describing the radio results was published Jan. 13 in The Astrophysical Journal Letters.
After the outburst, the black hole appeared to return to a quiet state, with a lull in activity for nearly a year. But by April 2023, a team led by Sibasish Laha at UMBC and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, had noted a steady, months-long increase in low-energy X-rays in measurements by NASA’s Neil Gehrels Swift Observatory and NICER (Neutron star Interior Composition Explorer) telescope on the International Space Station. This monitoring program, which also includes observations from NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) and ESA’s (European Space Agency) XMM-Newton mission, continues.
The increase in X-rays triggered the UMBC team to make new radio observations, which indicated a strong and highly unusual radio flare was underway. The scientists then began intensive observations using the NRAO’s (National Radio Astronomy Observatory) VLBA (Very Long Baseline Array) and other facilities. The VLBA, a network of radio telescopes spread across the U.S., combines signals from individual dishes to create what amounts to a powerful, high-resolution radio camera. This allows the VLBA to detect features less than a light-year across at 1ES 1927+654’s distance.
Active galaxy 1ES 1927+654, circled, has exhibited extraordinary changes since 2018, when a major outburst occurred in visible, ultraviolet, and X-ray light. The galaxy harbors a central black hole weighing about 1.4 million solar masses and is located 270 million light-years away. Pan-STARRS Radio data from February, April, and May 2024 reveals what appear to be jets of ionized gas, or plasma, extending from either side of the black hole, with a total size of about half a light-year. Astronomers have long puzzled over why only a fraction of monster black holes produce powerful plasma jets, and these observations may provide critical clues.
“The launch of a black hole jet has never been observed before in real time,” Meyer noted. “We think the outflow began earlier, when the X-rays increased prior to the radio flare, and the jet was screened from our view by hot gas until it broke out early last year.”
A paper exploring that possibility, led by Laha, is under review at The Astrophysical Journal. Both Meyer and Megan Masterson, a doctoral candidate at the Massachusetts Institute of Technology in Cambridge who also presented at the meeting, are co-authors.
Using XMM-Newton observations, Masterson found that the black hole exhibited extremely rapid X-ray variations between July 2022 and March 2024. During this period, the X-ray brightness repeatedly rose and fell by 10% every few minutes. Such changes, called millihertz quasiperiodic oscillations, are difficult to detect around supermassive black holes and have been observed in only a handful of systems to date.
“One way to produce these oscillations is with an object orbiting within the black hole’s accretion disk. In this scenario, each rise and fall of the X-rays represents one orbital cycle,” Masterson said.
If the fluctuations were caused by an orbiting mass, then the period would shorten as the object fell ever closer to the black hole’s event horizon, the point of no return. Orbiting masses generate ripples in space-time called gravitational waves. These waves drain away orbital energy, bringing the object closer to the black hole, increasing its speed, and shortening its orbital period.
Over two years, the fluctuation period dropped from 18 minutes to just 7 — the first-ever measurement of its kind around a supermassive black hole. If this represented an orbiting object, it was now moving at half the speed of light. Then something unexpected happened — the fluctuation period stabilized.
In this artist’s concept, matter is stripped from a white dwarf (sphere at lower right) orbiting within the innermost accretion disk surrounding 1ES 1927+654’s supermassive black hole. Astronomers developed this scenario to explain the evolution of rapid X-ray oscillations detected by ESA’s (European Space Agency) XMM-Newton satellite. ESA’s LISA (Laser Interferometer Space Antenna) mission, due to launch in the next decade, should be able to confirm the presence of an orbiting white dwarf by detecting the gravitational waves it produces. NASA/Aurore Simonnet, Sonoma State University “We were shocked by this at first,” Masterson explained. “But we realized that as the object moved closer to the black hole, its strong gravitational pull could begin to strip matter from the companion. This mass loss could offset the energy removed by gravitational waves, halting the companion’s inward motion.”
So what could this companion be? A small black hole would plunge straight in, and a normal star would quickly be torn apart by the tidal forces near the monster black hole. But the team found that a low-mass white dwarf — a stellar remnant about as large as Earth — could remain intact close to the black hole’s event horizon while shedding some of its matter. A paper led by Masterson summarizing these results will appear in the Feb. 13 edition of the journal Nature.
This model makes a key prediction, Masterson notes. If the black hole does have a white dwarf companion, the gravitational waves it produces will be detectable by LISA (Laser Interferometer Space Antenna), an ESA mission in partnership with NASA that is expected to launch in the next decade.
Download high-resolution images from NASA’s Scientific Visualization Studio
By Francis Reddy
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media Contacts:
Claire Andreoli
301-286-1940
claire.andreoli@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Jill Malusky
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National Radio Astronomy Observatory, Charlottesville, Va.
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Last Updated Jan 13, 2025 Related Terms
Active Galaxies Astrophysics Black Holes Galaxies, Stars, & Black Holes Goddard Space Flight Center Jet Propulsion Laboratory Neil Gehrels Swift Observatory NICER (Neutron star Interior Composition Explorer) NuSTAR (Nuclear Spectroscopic Telescope Array) Radio Astronomy Supermassive Black Holes The Universe White Dwarfs X-ray Astronomy XMM-Newton (X-ray Multi-Mirror Newton) View the full article
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By NASA
On Jan. 7, 1610, Italian astronomer Galileo Galilei peered through his newly improved 20-power homemade telescope at the planet Jupiter. He noticed three other points of light near the planet, at first believing them to be distant stars. Observing them over several nights, he noted that they appeared to move in the wrong direction with regard to the background stars and they remained in Jupiter’s proximity but changed their positions relative to one another. Four days later, he observed a fourth point of light near the planet with the same unusual behavior. By Jan. 15, Galileo correctly concluded that he had discovered four moons orbiting around Jupiter, providing strong evidence for the Copernican theory that most celestial objects did not revolve around the Earth.
Two of Galileo’s telescopes.National Geographic. Painting by Giuseppe Bertini (1858) of Galileo demonstrating his telescope to the Doge of Venice.gabrielevanin.it Page from Galileo’s notebook about his observations of Jupiter’s satellites.University of Michigan Special Collections Library. In March 1610, Galileo published his discoveries of Jupiter’s satellites and other celestial observations in a book titled Siderius Nuncius (The Starry Messenger). As their discoverer, Galileo had naming rights to Jupiter’s satellites. He proposed to name them after his patrons the Medicis and astronomers called them the Medicean Stars through much of the seventeenth century, although in his own notes Galileo referred to them by the Roman numerals I, II, III, and IV, in order of their distance from Jupiter. Astronomers still refer to the four moons as the Galilean satellites in honor of their discoverer.
In 1614, the German astronomer Johannes Kepler suggested naming the satellites after mythological figures associated with Jupiter, namely Io, Europa, Ganymede, and Callisto, but his idea didn’t catch on for more than 200 years. Scientists didn’t discover any more satellites around Jupiter until 1892 when American astronomer E.E. Barnard found Jupiter’s fifth moon Amalthea, much smaller than the Galilean moons and orbiting closer to the planet than Io. It was the last satellite in the solar system found by visual observation – all subsequent discoveries occurred via photography or digital imaging. As of today, astronomers have identified 95 moons orbiting Jupiter.
Image of Jupiter and three of its four Galilean satellites through an amateur telescope, similar to what Galileo might have seen. Hubble Space Telescope image of Jupiter and three of its four Galilean satellites during a rare triple transit. Although each of the Galilean satellites has unique features, such as the volcanoes of Io, the heavily cratered surface of Callisto, and the magnetic field of Ganymede, scientists have focused more attention on Europa due to the tantalizing possibility that it might be hospitable to life. In the 1970s, NASA’s Pioneer 10 and 11 and Voyager 1 and 2 spacecraft took ever increasingly detailed images of the large satellites including Europa during their flybys of Jupiter. The photographs revealed Europa to have the smoothest surface of any object in the solar system, indicating a relatively young crust, and also one of the brightest of any satellite indicating a highly reflective surface. These features led scientists to hypothesize that Europa is covered by an icy crust floating on a subsurface salty ocean. They further postulated that tidal heating caused by Jupiter’s gravity reforms the surface ice layer in cycles of melting and freezing.
Image of Europa taken by Pioneer 10 during its flyby of Jupiter in 1973. Image of Europa taken by Voyager 1 during its 1979 flyby of Jupiter. Image of Europa taken by Voyager 2 during its 1979 flyby of Jupiter. More detailed observations from NASA’s Galileo spacecraft that orbited Jupiter between 1995 and 2003 and completed 11 close encounters with Europa revealed that long linear features on its surface may indicate tidal or tectonic activity. Reddish-brown material along the fissures and in splotches elsewhere on the surface may contain salts and sulfur compounds transported from below the crust and modified by radiation. Observations from the Hubble Space Telescope and re-analysis of images from Galileo revealed possible plumes emanating from beneath Europa’s crust, lending credence to that hypothesis. While the exact composition of this material is not known, it likely holds clues to whether Europa may be hospitable to life.
Global view of Europa from the Galileo spacecraft. More detailed views of varied terrain on Europa from Galileo. Cutaway illustration of Europa’s icy crust, subsurface ocean and possible vents that transport material to the surface. Future robotic explorers of Europa may answer some of the outstanding questions about this unique satellite of Jupiter. NASA’s Europa Clipper set off in October 2024 on a 5.5-year journey to Jupiter. After its arrival in 2030, the spacecraft will enter orbit around the giant planet and conduct 49 flybys of Europa during its four-year mission. Managed by the Jet Propulsion Laboratory in Pasadena, California, and the Applied Physics Laboratory at Johns Hopkins University in Baltimore, Maryland, Europa Clipper will carry nine instruments including imaging systems and a radar to better understand the structure of the icy crust. Data from Europa Clipper will complement information returned by the European Space Agency’s JUICE (Jupiter Icy Moon Explorer) spacecraft. Launched in April 2023, JUICE will first enter orbit around Jupiter in 2031 and then enter orbit around Ganymede in 2034. The spacecraft also plans to conduct studies of Europa complementary with Europa Clipper’s. The two spacecraft should greatly increase our understanding of Europa and perhaps uncover new mysteries.
Illustration of the Europa Clipper spacecraft investigating Europa. Illustration of the JUICE spacecraft exploring Europa.European Space Agency. View the full article
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By Amazing Space
Winter Sky Guide: Orion, Pleiades & Jupiter Alignment | Meteor Shower Captured! Stargazing
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By European Space Agency
Don’t miss the final ESA Impact of the year!
Your interactive gateway to the most captivating stories and stunning visuals from ESA.
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