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Hubble Astronomers Check the Prescription of a Cosmic Lens
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By NASA
5 min read
NASA’s NICER Maps Debris From Recurring Cosmic Crashes
Lee esta nota de prensa en español aquí.
For the first time, astronomers have probed the physical environment of repeating X-ray outbursts near monster black holes thanks to data from NASA’s NICER (Neutron star Interior Composition Explorer) and other missions.
Scientists have only recently encountered this class of X-ray flares, called QPEs, or quasi-periodic eruptions. A system astronomers have nicknamed Ansky is the eighth QPE source discovered, and it produces the most energetic outbursts seen to date. Ansky also sets records in terms of timing and duration, with eruptions every 4.5 days or so that last approximately 1.5 days.
“These QPEs are mysterious and intensely interesting phenomena,” said Joheen Chakraborty, a graduate student at the Massachusetts Institute of Technology in Cambridge. “One of the most intriguing aspects is their quasi-periodic nature. We’re still developing the methodologies and frameworks we need to understand what causes QPEs, and Ansky’s unusual properties are helping us improve those tools.”
Watch how astronomers used data from NASA’s NICER (Neutron star Interior Composition Explorer) to study a mysterious cosmic phenomenon called a quasi-periodic eruption, or QPE.
NASA’s Goddard Space Flight Center Ansky’s name comes from ZTF19acnskyy, the moniker of a visible-light outburst seen in 2019. It was located in a galaxy about 300 million light-years away in the constellation Virgo. This event was the first indication that something unusual might be happening.
A paper about Ansky, led by Chakraborty, was published Tuesday in The Astrophysical Journal.
A leading theory suggests that QPEs occur in systems where a relatively low-mass object passes through the disk of gas surrounding a supermassive black hole that holds hundreds of thousands to billions of times the Sun’s mass.
When the lower-mass object punches through the disk, its passage drives out expanding clouds of hot gas that we observe as QPEs in X-rays.
Scientists think the eruptions’ quasi-periodicity occurs because the smaller object’s orbit is not perfectly circular and spirals toward the black hole over time. Also, the extreme gravity close to the black hole warps the fabric of space-time, altering the object’s orbits so they don’t close on themselves with each cycle. Scientists’ current understanding suggests the eruptions repeat until the disk disappears or the orbiting object disintegrates, which may take up to a few years.
A system astronomers call Ansky, in the galaxy at the center of this image, is home to a recently discovered series of quasi-periodic eruptions. Sloan Digital Sky Survey “Ansky’s extreme properties may be due to the nature of the disk around its supermassive black hole,” said Lorena Hernández-García, an astrophysicist at the Millennium Nucleus on Transversal Research and Technology to Explore Supermassive Black Holes, the Millennium Institute of Astrophysics, and University of Valparaíso in Chile. “In most QPE systems the supermassive black hole likely shreds a passing star, creating a small disk very close to itself. In Ansky’s case, we think the disk is much larger and can involve objects farther away, creating the longer timescales we observe.”
Hernández-García, in addition to being a co-author on Chakraborty’s paper, led the study that discovered Ansky’s QPEs, which was published in April in Nature Astronomy and used data from NICER, NASA’s Neil Gehrels Swift Observatory and Chandra X-ray Observatory, as well as ESA’s (European Space Agency’s) XMM-Newton space telescope.
NICER’s position on the International Space Station allowed it to observe Ansky about 16 times every day from May to July 2024. The frequency of the observations was critical in detecting the X-ray fluctuations that revealed Ansky produces QPEs.
Chakraborty’s team used data from NICER and XMM-Newton to map the rapid evolution of the ejected material driving the observed QPEs in unprecedented detail by studying variations in X-ray intensity during the rise and fall of each eruption.
The researchers found that each impact resulted in about a Jupiter’s worth of mass reaching expansion velocities around 15% of the speed of light.
The NICER (Neutron star Interior Composition Explorer) X-ray telescope is reflected on NASA astronaut and Expedition 72 flight engineer Nick Hague’s spacesuit helmet visor in this high-flying “space-selfie” taken during a spacewalk on Jan. 16, 2025. NASA/Nick Hague The NICER telescope’s ability to frequently observe Ansky from the space station and its unique measurement capabilities also made it possible for the team to measure the size and temperature of the roughly spherical bubble of debris as it expanded.
“All NICER’s Ansky observations used in these papers were collected after the instrument experienced a ‘light leak’ in May 2023,” said Zaven Arzoumanian, the mission’s science lead at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Even though the leak – which was patched in January – affected the telescope’s observing strategy, NICER was still able to make vital contributions to time domain astronomy, or the study of changes in the cosmos on timescales we can see.”
After the repair, NICER continued observing Ansky to explore how the outbursts have evolved over time. A paper about these results, led by Hernández-García and co-authored by Chakraborty, is under review.
Observational studies of QPEs like Chakraborty’s will also play a key role in preparing the science community for a new era of multimessenger astronomy, which combines measurements using light, elementary particles, and space-time ripples called gravitational waves to better understand objects and events in the universe.
One goal of ESA’s future LISA (Laser Interferometer Space Antenna) mission, in which NASA is a partner, is to study extreme mass-ratio inspirals — or systems where a low-mass object orbits a much more massive one, like Ansky. These systems should emit gravitational waves that are not observable with current facilities. Electromagnetic studies of QPEs will help improve models of those systems ahead of LISA’s anticipated launch in the mid-2030s.
“We’re going to keep observing Ansky for as long as we can,” Chakraborty said. “We’re still in the infancy of understanding QPEs. It’s such an exciting time because there’s so much to learn.”
Download images and videos through NASA’s Scientific Visualization Studio.
By Jeanette Kazmierczak
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 May 06, 2025 Editor Jeanette Kazmierczak Location Goddard Space Flight Center Related Terms
The Universe Astrophysics Black Holes Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research International Space Station (ISS) ISS Research NICER (Neutron star Interior Composition Explorer) Science & Research Supermassive Black Holes X-ray Astronomy View the full article
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By NASA
This NASA/ESA Hubble Space Telescope image features a peculiar spiral galaxy called Arp 184 or NGC 1961.ESA/Hubble & NASA, J. Dalcanton, R. J. Foley (UC Santa Cruz), C. Kilpatrick A beautiful but skewed spiral galaxy dazzles in this NASA/ESA Hubble Space Telescope image. The galaxy, called Arp 184 or NGC 1961, sits about 190 million light-years away from Earth in the constellation Camelopardalis (The Giraffe).
The name Arp 184 comes from the Atlas of Peculiar Galaxies compiled by astronomer Halton Arp in 1966. It holds 338 galaxies that are oddly shaped and tend to be neither entirely elliptical nor entirely spiral-shaped. Many of the galaxies are in the process of interacting with other galaxies, while others are dwarf galaxies without well-defined structures. Arp 184 earned its spot in the catalog thanks to its single broad, star-speckled spiral arm that appears to stretch toward us. The galaxy’s far side sports a few wisps of gas and stars, but it lacks a similarly impressive spiral arm.
This Hubble image combines data from three Snapshot observing programs, which are short observations that slotted into time gaps between other proposals. One of the three programs targeted Arp 184 for its peculiar appearance. This program surveyed galaxies listed in the Atlas of Peculiar Galaxies as well as A Catalogue of Southern Peculiar Galaxies and Associations, a similar catalog compiled by Halton Arp and Barry Madore.
The remaining two Snapshot programs looked at the aftermath of fleeting astronomical events like supernovae and tidal disruption events — like when a supermassive black hole rips a star apart after it wanders too closely. Since Arp 184 hosted four known supernovae in the past three decades, it is a rich target for a supernova hunt.
Image credit: ESA/Hubble & NASA, J. Dalcanton, R. J. Foley (UC Santa Cruz), C. Kilpatrick
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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 Images a Peculiar Spiral
This NASA/ESA Hubble Space Telescope image features a peculiar spiral galaxy called Arp 184 or NGC 1961. ESA/Hubble & NASA, J. Dalcanton, R. J. Foley (UC Santa Cruz), C. Kilpatrick A beautiful but skewed spiral galaxy dazzles in this NASA/ESA Hubble Space Telescope image. The galaxy, called Arp 184 or NGC 1961, sits about 190 million light-years away from Earth in the constellation Camelopardalis (The Giraffe).
The name Arp 184 comes from the Atlas of Peculiar Galaxies compiled by astronomer Halton Arp in 1966. It holds 338 galaxies that are oddly shaped and tend to be neither entirely elliptical nor entirely spiral-shaped. Many of the galaxies are in the process of interacting with other galaxies, while others are dwarf galaxies without well-defined structures. Arp 184 earned its spot in the catalog thanks to its single broad, star-speckled spiral arm that appears to stretch toward us. The galaxy’s far side sports a few wisps of gas and stars, but it lacks a similarly impressive spiral arm.
This Hubble image combines data from three Snapshot observing programs, which are short observations that slotted into time gaps between other proposals. One of the three programs targeted Arp 184 for its peculiar appearance. This program surveyed galaxies listed in the Atlas of Peculiar Galaxies as well as A Catalogue of Southern Peculiar Galaxies and Associations, a similar catalog compiled by Halton Arp and Barry Madore.
The remaining two Snapshot programs looked at the aftermath of fleeting astronomical events like supernovae and tidal disruption events — like when a supermassive black hole rips a star apart after it wanders too closely. Since Arp 184 hosted four known supernovae in the past three decades, it is a rich target for a supernova hunt.
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 May 01, 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
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Hubble’s Galaxies
Tracing the Growth of Galaxies
Reshaping Our Cosmic View: Hubble Science Highlights
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By NASA
ESA/Hubble & NASA, L. C. Ho, D. Thilker Today’s rather aquatic-themed NASA/ESA Hubble Space Telescope image features the spiral galaxy Messier 77, also known as the Squid Galaxy, which sits 45 million light-years away in the constellation Cetus (The Whale).
The designation Messier 77 comes from the galaxy’s place in the famous catalog compiled by the French astronomer Charles Messier. Another French astronomer, Pierre Méchain, discovered the galaxy in 1780. Both Messier and Méchain were comet hunters who cataloged nebulous objects that could be mistaken for comets.
Messier, Méchain, and other astronomers of their time mistook the Squid Galaxy for either a spiral nebula or a star cluster. This mischaracterization isn’t surprising. More than a century would pass between the discovery of the Squid Galaxy and the realization that the ‘spiral nebulae’ scattered across the sky were not part of our galaxy but were in fact separate galaxies millions of light-years away. The Squid Galaxy’s appearance through a small telescope — an intensely bright center surrounded by a fuzzy cloud — closely resembles one or more stars wreathed in a nebula.
The name ‘Squid Galaxy’ is recent, and stems from the extended, filamentary structure that curls around the galaxy’s disk like the tentacles of a squid. The Squid Galaxy is a great example of how advances in technology and scientific understanding can completely change our perception of an astronomical object — and even what we call it!
Hubble previously released an image of M77 in 2013. This new image incorporates recent observations made with different filters and updated image processing techniques which allow astronomers to see the galaxy in more detail.
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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 Visits Glittering Cluster, Capturing Its Ultraviolet Light
This NASA/ESA Hubble Space Telescope image features the globular cluster Messier 72 (M72). ESA/Hubble & NASA, A. Sarajedini, G. Piotto, M. Libralato As part of ESA/Hubble’s 35th anniversary celebrations, the European Space Agency (ESA) shared new images that revisited stunning, previously released Hubble targets with the addition of the latest Hubble data and new processing techniques.
ESA/Hubble released new images of NGC 346, the Sombrero Galaxy, and the Eagle Nebula earlier in the month. Now they are revisiting the star cluster Messier 72 (M72).
M72 is a collection of stars, formally known as a globular cluster, located in the constellation Aquarius roughly 50,000 light-years from Earth. The intense gravitational attraction between the closely packed stars gives globular clusters their regular, spherical shape. There are roughly 150 known globular clusters associated with the Milky Way galaxy.
The striking variety in the color of the stars in this image of M72, particularly compared to the original image, results from the addition of ultraviolet observations to the previous visible-light data. The colors indicate groups of different types of stars. Here, blue stars are those that were originally more massive and have reached hotter temperatures after burning through much of their hydrogen fuel; the bright red objects are lower-mass stars that have become red giants. Studying these different groups help astronomers understand how globular clusters, and the galaxies they were born in, initially formed.
Pierre Méchain, a French astronomer and colleague of Charles Messier, discovered M72 in 1780. It was the first of five star clusters that Méchain would discover while assisting Messier. They recorded the cluster as the 72nd entry in Messier’s famous collection of astronomical objects. It is also one of the most remote clusters in the catalog.
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 25, 2025 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Hubble Space Telescope Astrophysics Astrophysics Division Globular Clusters Goddard Space Flight Center Star Clusters Stars The Universe Keep Exploring Discover More Topics From Hubble
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Hubble’s Star Clusters
Hubble’s 35th Anniversary
Hubble’s Night Sky Challenge
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