For the first time, scientists have used NASA’s IXPE (Imaging X-ray Polarimetry Explorer) to directly measure the magnetic fields of PSR J1101−6101, a pulsar located within what is often referred to as the Lighthouse Nebula. The results provide new insight into the structure of some of the most extreme objects in the cosmos, as NASA continues to explore the secrets of how the universe works. A paper describing the results published Thursday in the Astrophysical Journal.

Fast facts

• A pulsar is a type of neutron star with a strong magnetic field that spins incredibly fast. The pulsar at the center of the Lighthouse Nebula is rotating 16 times per second.
• Neutron stars are the leftover cores of massive stars, formed at the end of their life cycles, that possess more mass than the Sun. They are condensed down to the size of a city, making them natural laboratories for studying extreme physics.

• Polarization is a property of light that describes the direction of its electric field vibrations. The polarization degree is a measurement of how aligned those vibrations are with each other.

In June 2025, IXPE spent nearly 18 days focused on the Lighthouse Nebula.

Astronomers studied two narrow X-ray offshoots extending from the pulsar to better understand how electrons at nearly the speed of light interact with this energetic system. The longer offshoot is known as the “filament,” and the shorter one is the “trail.”

When high-energy particles from the pulsar collide with the gas of interstellar space, they form a bow shock, like the bow wave formed at the front of a speeding boat. Most particles become trapped behind this bow shock, forming the turbulent trail behind the pulsar.

Researchers have suspected since 2008 that the highest-energy particles escape through this bow shock into interstellar space, flowing along the galaxy’s magnetic field lines to create the nebula’s long, thin filament.

“We wanted to test that theory,” said Jack Dinsmore, graduate student at Stanford University, who led the study. “The ‘smoking gun’ would come by measuring the polarization of the light, which indicates the magnetic field direction. If the magnetic field points along the filament, that confirms that the filament’s particles are flowing along the field.”

One challenge with these measurements is that the Lighthouse Nebula is relatively faint. To address this, IXPE scientists developed advanced analysis methods that use every bit of data, avoiding simplifying steps that could limit information. With these new tools and the new observations of the Lighthouse, the science team successfully measured the filament’s polarization. These techniques also gave a polarization measurement of the trail, and the pulsar’s emission signal.

Their analysis confirmed with more than 99% confidence that the magnetic field does indeed align with the particles’ flow.

While the parallel direction confirms models for the particle’s motion, the polarization degree was high enough to raise new questions.

“Many of the models for filaments assume strong magnetic turbulence,” said Roger Romani, a Stanford University professor who co-authored this paper. “The high polarization degree we measured indicates lower turbulence than such models require.”

The IXPE observations also showed that the magnetic field responsible for X-ray emission had to be parallel to the trail. However, the authors collected radio frequency observations showing a magnetic field pointing almost exactly perpendicular.

“The striking divergence in magnetic field orientations observed between radio and X-ray wavelengths provides compelling evidence for the highly structured nature of these objects,” said Niccolò Bucciantini of the Italian National Institute for Astrophysics and co-author of the study. “This marks the first clear indication that particles of different energies occupy distinct regions within the system, hinting at the presence of multiple, and potentially very different, acceleration mechanisms at work.”

More about IXPE

The IXPE mission, 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. It is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama, and BAE Systems, Inc. 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

Like fresh fireworks launched against a background of dissipating smoke, blue and white stars shine brilliantly against a crimson background of glowing gas in this image of stellar nursery LH 95 from NASA’s Hubble Space Telescope.

LH 95 is a region in the Large Magellanic Cloud, a dwarf galaxy that orbits the Milky Way. Low-mass infant stars live alongside massive blue giant stars in what is known as a stellar association, one of many in the Large Magellanic Cloud.

The LH 95 region’s most massive stars, possessing at least three times the mass of the Sun and visible here as the largest and brightest blue stars, expel ultraviolet radiation and stellar winds that both heat and shape the surrounding hydrogen gas. Dark filaments stand out in sharp contrast against the glowing hydrogen where denser dust lanes resist erosion.

In this image, blue indicates the shorter wavelengths that are visible light, while red depicts the longer wavelengths of visible light, as well as some near-infrared light. Colors in Hubble images are chosen based on standard image processing techniques to best represent the wavelengths of light that pass through the filters used in the observation. The gas of the nebula glows crimson due to hydrogen-alpha emissions.

Hydrogen-alpha is an excellent indicator of star formation, allowing astronomers to identify very young stars embedded in this glowing gas. Researchers found developing stars still gathering material from the disks of gas and dust around them. In fact, LH 95 is home to an extraordinary 2,500 stars that have accumulated almost all of their critical mass but have not yet “turned on” by beginning fusion reactions. These stars, called “pre-main-sequence stars,” have formed from collapsing clouds of gas and are still contracting. They will soon begin burning hydrogen in their cores to become full stars.

By studying these forming stars, researchers confirmed that the stars’ accretion rate ― the rate at which they accumulate matter ― decreased with age, as expected. However, they also learned that accretion can persist for several million years, longer than sometimes assumed. This information helps refine our understanding of how young stars keep growing and how their disks evolve.

Researchers noted that distinct generations of stars in LH 95 exist side-by-side, indicating that rather than forming stars in a single event, the region produces multiple stellar generations over an extended period.

The most massive star in LH 95 (above center, slightly left) has about 60-70 times the mass of the Sun and is about a million years younger than the rest of stars in the system, which appear to be around 4 million years old. Massive stars like these burn through their fuel quickly and die in supernova explosions.

With its rich stellar population, LH 95 is valued by astronomers for providing a way to observe forming stars at relatively close range in an environment with less obscuring dust than similar regions of the Milky Way.

As one of NASA’s flagship observatories, Hubble has produced a wealth of scientific discoveries over more than 30 years in orbit. Its observations are expanded upon and enhanced by observations with other NASA missions, including the infrared-detecting Webb Space Telescope and the upcoming Nancy Grace Roman Space Telescope, which is scheduled to launch in late summer.

Explore More

Media Contact:

Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

In celebration of the 250th birthday of the United States, NASA has unveiled four cosmic images from its Chandra X-ray Observatory rendered in red, white, and blue that represent the wonders of the universe the agency explores. The images are accompanied by a trio of new sonifications – a technique that translates astronomical data into sounds.

The image set begins with Cassiopeia A in the top panel, where X-rays from Chandra (represented in blue and purple) have been combined with an infrared image from NASA’s James Webb Space Telescope (red and white). Chandra’s X-ray vision reveals the blast wave that tore through the star, as well as elements in the debris field like iron, calcium, and oxygen. Webb’s infrared data also shows the expanding shell of material from the explosion and cosmic dust throughout the remnant.

 In the bottom row, the first image on the left is the nebula NGC 3603, which contains a massive cluster of stars and is located in the Milky Way Galaxy. This new composite image contains Chandra’s X-ray data (red and white) and shows diffuse emissions near the galaxy’s center along with point-like X-ray sources throughout the middle of the image. Optical, infrared, and ultraviolet light from NASA’s Hubble Space Telescope (red-orange, green, blue, and yellow) reveal stars in the center of the image and dust and gas toward the bottom. The combined layering of the colors makes this nebula and the stars forming within it appear primarily red, white, and blue, with X-rays showing the sparkling lights of young stars.

The middle panel of the bottom row is a new look at the galaxy NGC 4736, also known as Messier 94. In this image, X-rays of different wavelengths from Chandra (red, orange, and blue) are layered with a visible light image from astrophotographers using their telescopes on the ground (red, green, and blue). Messier 94 is a spiral galaxy with a bright inner ring around it, called a starburst ring, where new stars are forming, perhaps fueled by gas driven in the unique oval-shaped structure seen here.

The final image in this red, white, and blue quartet features ZwCl 0024+1652. This is a distant galaxy cluster in which astronomers have found evidence for dark matter by using specially processed data from Hubble (blue). Another image from Hubble reveals the individual galaxies in the cluster (appearing as yellow and white). X-ray data from Chandra shows the enormous reservoir of superheated gas that pervades this galaxy cluster (red) with much more mass than all the galaxies taken together.

New sonifications of the three images along the bottom row of this mosaic are also available, allowing listeners to experience data through sound.

The translation of NGC 3603 into sound begins with a left to right scan, where the brightnesses of the sources once again dictate volume. Chandra’s observations of compact sources sprinkled throughout the galaxy are heard as piano notes, while the diffuse X-ray emission is mapped to a range of audio frequencies. The Hubble optical data is played as sustained tones and acoustic guitar harmonics.

In the sonification of NGC 4736, the radar-like scan moves clockwise, and the brightness of the sources dictates the volume of the sounds. X-rays from Chandra have been turned into wind-like sounds that follow the shape of the X-ray emission. Neutron stars and stellar-mass black holes (known as “compact sources”) detected by Chandra are mapped to pitched tones on a glass marimba. Optical data from ground-based observations is mapped to musically pitched tones, creating a low drone, while stars and background galaxies are heard as a soft piano.

For ZwCl 0024+1652, the sonification begins as a circle on the outside of the image and moves inward. The volume is linked to the brightness of the data, reaching one peak as the circle passes over the dark matter detected by inference from Hubble optical observations and another as it reaches the core. The background stars are heard as a swelling glockenspiel-like sound, and the galaxies are played on a piano. Chandra’s X-rays, which dominate the center of the galaxy cluster and reveal superheated gas, are represented by airy synthesizer notes.

The sonification program is led by the Chandra X-ray Center (CXC) and included as part of NASA’s Universe of Learning program. The collaboration was driven by visualization scientist Kimberly Arcand, (CXC), Matt Russo, astrophysicist; and Andrew Santaguida, musician, SYSTEM Sounds project; along with Christine Malec, consultant. Previously released sonifications of data from Cassiopeia A can be found at chandra.si.edu/sound.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

To learn more about NASA’s Chandra mission, visit:

https://nasa.gov/chandra

Visual Description

In celebration of the 250th birthday of the United States, this release includes a series of images featuring four wonders of the universe, rendered in red, white, and blue. The images contain X-ray data from the Chandra X-ray Observatory, optical and infrared data from the Hubble Space Telescope and the James Webb Space Telescope, as well as ground-based telescopes.

The main image set features composite images of the four individual objects; Cassiopeia A, NGC 3603, M94/NGC 4736, and ZwCl 0024+1652.

Cassiopeia A occupies the top panel of the frame, significantly larger than the other images in the set. The cloudy blast-wave of the supernova remnant is ring-like in shape, streaked with veins of iron, calcium, and oxygen. Here, presented in red, white, and blue, the remnant resembles an electrified donut, crackling with marbled veins of strawberry and blueberry icing.

At our lower left of the image set is the nebula NCG 3603, which contains a massive cluster of stars on the other side of the Milky Way galaxy. Here, a tight cluster of neon red and white stars packs the center of the image, dissipating as it reaches the outer edges of the panel. Sweeping in at the lower corners of the image are hazy blue clouds resembling sheets of gauze.

Centered at the bottom of the image set is the galaxy NGC 4736, also known as Messier 94 (M94). Here, the spiral galaxy is seen face on, with concentric pale violet cloud rings flecked with scores of stars in white, pale blue, soft red, and golden yellow. The inner ring of the galaxy is bright, and rosy yellow in color. This is a starburst ring, where new stars are forming.

At our bottom right of the image set is the distant galaxy cluster ZwCl 0024+1652. The image is packed with streaks and specks in golden yellow and brilliant white. Upon close inspection, each streak and speck is revealed to be an individual galaxy, some with discernible spiral shapes. At the center of the image is a round pool of bright red light, surrounded by royal blue haze. The red light represents X-ray observations by Chandra, which reveal an enormous reservoir of superheated gas pervading the cluster. The blue haze represents specially-processed data from Hubble, suggesting evidence of dark matter.

This release also includes new sonifications of the three images presented in the bottom row of this data set, allowing listeners to experience the data through sound.

Read more from NASA’s Chandra X-ray Observatory

News Media Contact

Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu

Joel Wallace
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
joel.w.wallace@nasa.gov