NASA telescope IXPE maps magnetic fields of the Lighthouse pulsar

Scientists have utilized NASA’s Imaging X-ray Polarimetry Explorer (IXPE) to conduct the first direct measurements of the magnetic fields surrounding PSR J1101−6101. This pulsar, located within the Lighthouse Nebula, serves as a high-energy laboratory for studying how extreme celestial objects interact with their surroundings.

The research, which was published on July 9, 2026, in The Astrophysical Journal, relies on data collected during an 18-day observation period that took place in June 2025. By analyzing X-ray emissions from the pulsar, the team sought to clarify the mechanics behind the nebula’s unique structures: a long, narrow offshoot known as the “filament” and a shorter formation referred to as the “trail.”

Pulsars are dense, rapidly rotating neutron stars that represent the remnants of massive stellar cores. The pulsar at the center of the Lighthouse Nebula spins 16 times per second. As these objects rotate, they act as powerful electromagnetic generators, accelerating charged particles to speeds near that of light. When these particles collide with gas in interstellar space, they generate a bow shock, similar to the wake created by a moving vessel. While most particles remain trapped behind this shock to form the trail, researchers have long suspected that the most energetic particles escape into space to create the filament.

Jack Dinsmore, an undergraduate student at Stanford University who led the study, noted that the team looked for a specific signature to confirm this particle behavior. "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," Dinsmore stated via NASA. The team confirmed this alignment with more than 99% confidence.

Despite this confirmation, the observations revealed unexpected characteristics regarding magnetic turbulence. Roger Romani, a Stanford professor and co-author of the study, noted that many existing models for such filaments rely on the assumption of strong magnetic turbulence. The IXPE measurements, however, indicated a significantly lower degree of turbulence than those models predicted.

Furthermore, the study highlighted a discrepancy in magnetic field orientations depending on the wavelength of light being observed. While the X-ray data showed a magnetic field aligned with the particle flow, radio frequency observations of the same system indicate a field pointing almost exactly perpendicular to that path.

"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. 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."

Niccolò Bucciantini, Italian National Institute for Astrophysics and co-author, via NASA

Because the Lighthouse Nebula is relatively faint, the researchers were required to develop advanced analysis methods to maximize the utility of the IXPE data. These techniques allowed the team to measure polarization for the trail and the pulsar’s emission signal alongside the filament.

The IXPE mission is a collaboration between NASA and the Italian Space Agency, involving science partners from 12 countries. The project is led by NASA’s Marshall Space Flight Center, with spacecraft operations managed by BAE Systems, Inc. In coordination with the University of Colorado’s Laboratory for Atmospheric and Space Physics.