NASA Finds 84 Mysterious X-Ray Objects in Six Galaxies — Scientists Don’t Know What They Are

NASA’s Chandra X-ray Observatory has uncovered 84 unusual X-ray sources across six galaxies, revealing a previously unrecognized class of cosmic objects that behave unlike anything astronomers have seen before.

The mysterious objects produce unusually low-energy X-rays while emitting intense ultraviolet radiation, a combination that has puzzled researchers.

Scientists have named them “hypersoft X-ray sources”, and they believe the objects could help answer two major questions in astrophysics — including how some stars may eventually produce powerful Type Ia supernovae and what is stripping electrons from gas between stars in some galaxies.

The findings were published in Nature Astronomy in September 2026.

NASA Chandra Finds a New Class of Cosmic Objects

The discovery was made using archival observations from NASA’s Chandra X-ray Observatory.

Researchers searched through Chandra’s publicly available data looking for objects that appeared strongly in the lowest-energy X-ray images but disappeared when higher-energy X-rays were examined.

That unusual signature led astronomers to a total of 84 hypersoft X-ray sources spread across six different galaxies.

Two of the galaxies are spiral galaxies:

• Messier 31 (M31), the Andromeda Galaxy
• Messier 101 (M101), the Pinwheel Galaxy

The other four galaxies are elliptical galaxies.

The sources were found both in regions where stars are actively forming and in regions dominated by older stars.

What Are Hypersoft X-Ray Sources?

The name comes from the unusual nature of their X-ray emission.

Typical X-ray sources can produce powerful, relatively high-energy X-rays.

The newly identified objects are different.

They produce X-rays that are unusually soft, meaning the X-rays have relatively low energy.

At the same time, the objects appear to generate large amounts of energetic ultraviolet radiation.

That combination is what makes them so unusual.

Researchers have not yet determined exactly what type of astronomical object produces this behavior.

Scientists Don’t Yet Know What These Objects Are

The researchers believe the hypersoft sources could involve some of the most extreme objects in the universe.

Possible candidates include:

• Black holes
• Neutron stars
• White dwarfs

The scientists think these objects may exist in binary systems where a compact object pulls material away from a companion star.

As matter falls toward the compact object, it becomes extremely hot and can generate X-rays.

However, the newly discovered sources do not behave like previously known systems.

Their combination of unusually soft X-rays and powerful ultraviolet emission sets them apart.

Why Are the 84 Objects So Difficult to Detect?

The mystery partly comes down to the way their radiation travels through space.

The objects produce intense ultraviolet radiation, but ultraviolet light can be absorbed by hydrogen and helium gas between stars.

This creates a major observational problem.

The ultraviolet signal can be hidden before it reaches telescopes.

At the same time, the objects’ low-energy X-rays are difficult for X-ray observatories to detect.

As a result, these sources could have remained hidden in astronomical archives for years.

Researchers were able to find them by specifically searching Chandra observations for their unusual low-energy X-ray signature.

Seven Mysterious Objects Are Hiding in the Pinwheel Galaxy

One of the most visually striking examples is M101, also known as the Pinwheel Galaxy.

Researchers identified seven of the mysterious hypersoft sources in M101.

NASA’s composite image combines X-ray observations from Chandra with optical observations from the Hubble Space Telescope.

To a casual observer, the objects look like tiny points of light scattered among the galaxy’s enormous spiral arms.

But their radiation tells a very different story.

The marked objects produce an unusual combination of low-energy X-rays and intense ultraviolet radiation.

Could Black Holes or Neutron Stars Be Involved?

Possibly.

The research team believes the sources most likely involve compact objects pulling matter from companion stars.

A black hole, neutron star or white dwarf can gravitationally strip material from a nearby star.

That material forms a hot environment capable of producing energetic radiation.

However, the researchers have not established which type of compact object is responsible for the entire population.

It is also possible that more than one type of astronomical system is contributing to the observed population.

Further observations will be needed to determine the true nature of these sources.

The Discovery Could Help Explain Type Ia Supernovae

One of the most important implications involves Type Ia supernovae.

These powerful stellar explosions are extremely important to astronomy because they can be used to measure distances across the universe.

Observations of Type Ia supernovae played a major role in establishing that the expansion of the universe is accelerating.

But astronomers still have unanswered questions about exactly how these explosions are triggered.

Some white dwarf systems that pull material from companion stars could eventually become Type Ia supernovae.

The newly discovered hypersoft sources may provide clues about these systems before they explode.

Scientists are therefore interested in determining whether some of the newly identified sources represent stages in the evolution of systems that eventually produce Type Ia supernovae.

Could These Objects Explain Another Cosmic Mystery?

The discovery may also help explain a different astrophysical problem.

Scientists know that gas between stars in some galaxies can lose electrons through ionization.

Hot, massive stars contribute to this process, but researchers say they do not fully explain the observed levels of ionization in all environments.

The intense ultraviolet radiation produced by hypersoft X-ray sources could provide another source of ionizing radiation.

If these objects are common enough, they could influence the chemical and physical state of interstellar gas across galaxies.

Why Did Astronomers Find Them Only Now?

The answer is partly hidden in their unusual radiation.

The objects are difficult to detect because their X-rays are unusually low in energy.

Their strong ultraviolet emission creates another problem because gas between stars can absorb much of that radiation.

This combination effectively creates an observational blind spot.

By going back through Chandra’s archive and searching specifically for low-energy X-ray sources, researchers were able to identify objects that previous searches had overlooked.

The discovery demonstrates how astronomical archives can contain important discoveries even years after the original observations were collected.

How Many of These Objects Could Exist?

Scientists do not yet know the total population.

The researchers found 84 sources in six galaxies, but that does not mean only 84 exist.

The objects are difficult to detect, meaning many more could be hiding in other galaxies.

Researchers found the sources in both spiral and elliptical galaxies, suggesting that the phenomenon may not be restricted to one particular type of galactic environment.

The possibility of a much larger hidden population is one reason astronomers are interested in conducting additional searches.

The Objects Could Be Extremely Energetic

Despite their soft X-rays, these objects are not weak.

Research associated with the discovery indicates that some hypersoft X-ray sources can be extraordinarily luminous.

Their unusual radiation makes them difficult to classify using traditional categories of X-ray sources.

That combination — powerful energy output but unusually soft X-ray emission — is one of the central mysteries researchers now want to understand.

What Does This Mean for Our Understanding of Galaxies?

The discovery could change how scientists think about the sources of high-energy radiation in galaxies.

Astronomers often study galaxies by examining their stars, gas, dust, black holes and other energetic objects.

If hypersoft X-ray sources are widespread, they could represent a previously underestimated population of energetic systems.

Their ultraviolet radiation could influence surrounding gas, while some of the systems could potentially evolve into stellar explosions.

That would give the objects importance far beyond their unusual appearance in X-ray data.

What Happens Next?

The immediate goal is to determine exactly what these sources are.

Researchers need additional observations at different wavelengths to understand their properties.

Astronomers will also compare the objects with known populations of black-hole binaries, neutron-star systems and white-dwarf binaries.

Future observations could reveal whether all 84 objects belong to the same physical class or whether the group contains several different types of systems that produce similar radiation.

The team will also search additional galaxies for more hypersoft sources.

Why This Discovery Matters

The most important aspect of the discovery is that scientists have identified something they did not previously recognize as a distinct population.

The 84 sources are not simply another collection of ordinary X-ray binaries.

Their unusual combination of soft X-rays and strong ultraviolet radiation suggests that an important part of their physics is still missing from our understanding.

And because these objects may connect to two major astrophysical questions — the ionization of interstellar gas and the origins of Type Ia supernovae — understanding them could have consequences far beyond the initial discovery.

Key Facts

• Discovery: 84 hypersoft X-ray sources
• Observatory: NASA’s Chandra X-ray Observatory
• Galaxies: Six
• Notable galaxies: Andromeda (M31) and Pinwheel Galaxy (M101)
• Radiation: Unusually low-energy X-rays and intense ultraviolet radiation
• Possible objects: Black holes, neutron stars or white dwarfs in binary systems
• Research publication: Nature Astronomy
• Discovery method: Analysis of archival Chandra observations
• Major questions: Type Ia supernova origins and ionization of interstellar gas
• Status: Nature of the objects remains uncertain

Frequently Asked Questions

What are the 84 mysterious X-ray objects NASA discovered?

They are a newly identified group called hypersoft X-ray sources. They produce unusually low-energy X-rays and intense ultraviolet radiation.

Where were the 84 objects found?

Researchers found them in six galaxies, including the Andromeda Galaxy and the Pinwheel Galaxy, as well as four elliptical galaxies.

Are the mysterious objects black holes?

Scientists don’t know yet. The objects may involve black holes, neutron stars or white dwarfs pulling material from companion stars.

Why are they called hypersoft X-ray sources?

They are called hypersoft because their X-ray emission is dominated by unusually low-energy X-rays.

Could these objects become supernovae?

Some systems involving white dwarfs could potentially evolve toward Type Ia supernova explosions, but researchers have not established that all or even a particular subset of the newly identified sources will do so.

Why weren’t these objects discovered earlier?

Their low-energy X-rays are difficult to detect, while their ultraviolet radiation can be absorbed by gas between stars. This combination makes them unusually difficult to observe.

Are these objects inside the Milky Way?

The 84 sources in this study were identified in six other galaxies. The researchers suggest similar objects may exist in the Milky Way but could be difficult to detect because of intervening gas.

The Bigger Picture

Astronomy is full of objects that become visible only when scientists know exactly what to look for.

The discovery of these 84 hypersoft X-ray sources is a striking example.

The objects were not found by launching a new spacecraft or building a completely new telescope. Instead, researchers went back through data already collected by NASA’s Chandra X-ray Observatory and searched for an unusual pattern.

That search revealed a previously unrecognized population of cosmic sources.

Scientists now have a new mystery to solve: what exactly are these objects, and why do they produce such an unusual combination of radiation?

The answer could reveal new information about compact stars, binary systems, galaxy evolution and even the origins of some of the universe’s most important stellar explosions.

For now, the 84 objects remain one of the latest reminders that the universe can hide extraordinary phenomena in data astronomers have already collected.

Sources & References

Primary source: NASA Science — NASA’s Chandra Unveils Mysterious X-Ray Objects.

Chandra Press Release: NASA’s Chandra X-ray Observatory — NASA’s Chandra Unveils Mysterious X-ray Objects, September 9, 2026.

Research: Muhibullah et al., Nature Astronomy, 2026. The NASA release identifies the research as the source of the discovery.

Image: X-ray: NASA/CXC/University of Alabama/M. Muhibullah et al.; Optical: NASA/ESA/STScI; Image Processing: NASA/CXC/SAO/N. Wolk.

Editorial note: The exact nature of the hypersoft X-ray sources has not yet been established. Possible explanations involving black holes, neutron stars or white dwarfs remain under investigation and should not be presented as confirmed identifications.