The rare cosmic duo known as PSR J1023+0038 has been a subject of fascination for astronomers. This binary system consists of a rapidly rotating neutron star, also a pulsar, feeding off its low-mass companion star. As a result, an accretion disk forms around the neutron star, creating a complex environment that is ripe for study.

A team of international researchers, led by Maria Cristina Baglio from the Italian National Institute of Astrophysics (INAF), set their sights on this mysterious system using observations from NASA’s IXPE and other telescopes. Their goal was to uncover the source of the X-rays emanating from J1023, which would have significant implications for broader theories about particle acceleration, accretion physics, and the environments surrounding neutron stars across the universe.

The big question, as Baglio notes, is: “Where do the X-rays originate?” The answer lies in the pulsar wind, a chaotic stew of gases, shock waves, magnetic fields, and particles accelerated near the speed of light. This finding challenges conventional wisdom about neutron star emissions and opens up new avenues for research.

IXPE, launched in 2021, is the only telescope capable of measuring the angle of polarization in X-ray and optical light. By combining these observations with data from other telescopes, including the European Southern Observatory’s Very Large Telescope, NASA’s NICER, and the Karl G. Jansky Very Large Array, scientists were able to confirm that the same angle of polarization exists across different wavelengths. This is compelling evidence that a single, coherent physical mechanism underpins the light we observe.

“This interpretation challenges the conventional wisdom about neutron star emissions of radiation in binary systems,” said Francesco Coti Zelati from the Institute of Space Sciences in Barcelona, co-lead author of the findings. “IXPE has observed many isolated pulsars and found that the pulsar wind powers the X-rays. These new observations show that the pulsar wind powers most of the energy output of the system.”

Astronomers continue to study transitional millisecond pulsars, assessing how observed physical mechanisms compare with those of other pulsars and pulsar wind nebulae. Insights from these observations could help refine theoretical models describing how pulsar winds generate radiation – and bring researchers one step closer to fully understanding the physical mechanisms at work in these extraordinary cosmic systems.

IXPE continues to provide unprecedented data, enabling groundbreaking discoveries about celestial objects across the universe. As a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries, IXPE is leading the way in advancing our knowledge of the cosmos.

The Cosmic Conundrum: A Billion-Light-Year Hole Around Earth Unmasks Faster Space Expansion

Astronomers have long been puzzled by the discrepancy in the measured expansion rate of the universe, which they refer to as the Hubble tension. This conundrum has left scientists searching for a solution, and recent research suggests that our galaxy might be situated within a massive, billion-light-year hole that makes the cosmos expand faster here than in neighboring regions.

The idea is not new, but it gained momentum with the latest study presented at the Royal Astronomical Society’s National Astronomy Meeting (NAM) in Durham. The researchers’ theory proposes that our galaxy sits near the center of a large, local void, which would cause matter to be pulled by gravity towards the higher-density exterior of the void.

As the void empties out over time, the velocity of objects away from us would increase, giving the appearance of a faster local expansion rate. This potential solution to the Hubble tension is largely a local phenomenon, with little evidence that the expansion rate disagrees with expectations in the standard cosmology further back in time.

The researchers also used baryon acoustic oscillations (BAOs) – essentially the sound waves from the early universe – to support their theory. These sound waves travelled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form. They act as a standard ruler, whose angular size can be used to chart the cosmic expansion history.

By considering all available BAO measurements over the last 20 years, the researchers showed that a void model is about one hundred million times more likely than a void-free model with parameters designed to fit the CMB observations taken by the Planck satellite, the so-called homogeneous Planck cosmology.

The next step for researchers is to compare their local void model with other methods to estimate the history of the universe’s expansion. This involves looking at galaxies that are no longer forming stars and observing their spectra or light to find what kinds of stars they have and in what proportion.

Astronomers can then combine this age with the galaxy’s redshift – how much the wavelength of its light has been stretched – which tells us how much the universe has expanded while light from the galaxy was traveling towards us. This sheds light on the universe’s expansion history.

The Hubble constant was first proposed by Edwin Hubble in 1929 to express the rate of the universe’s expansion. It can be measured by observing the distance of celestial objects and how fast they are moving away from us. The Hubble tension refers to the discrepancy in the measured expansion rate of the universe, specifically between the value based on observations of the early universe and the value related to observations of the local universe.

Baryon acoustic oscillations provide an independent way to measure the expansion rate of the universe and how that rate has changed throughout cosmic history. The discovery of a billion-light-year hole around Earth might be just the solution scientists need to unravel the mysteries of the cosmos.

The discovery of 100 hidden ghost galaxies orbiting the Milky Way has sent shockwaves throughout the scientific community, sparking renewed interest in the Lambda Cold Dark Matter (LCDM) theory. This groundbreaking research, led by cosmologists at Durham University, has shed new light on the mysteries of galaxy formation and evolution.

Using a novel technique that combines high-resolution supercomputer simulations with advanced mathematical modeling, researchers have predicted the existence of dozens more satellite galaxies surrounding our home galaxy, orbiting at close distances. These so-called “orphan” galaxies are extremely faint, stripped almost entirely of their dark matter halos by the gravity of the Milky Way’s halo.

The findings suggest that there should be around 80 or potentially up to 100 more satellite galaxies than currently known, with approximately 30 newly discovered tiny Milky Way satellite candidates being a subset of this population. If confirmed, this would provide strong support for the LCDM theory and demonstrate the power of physics and mathematics in making precise predictions that can be tested by observational astronomers.

The research is funded by the European Research Council and the Science and Technology Facilities Council (STFC), with calculations performed on the Cosmology Machine (COSMA) supercomputer. The Royal Astronomical Society’s National Astronomy Meeting 2025 will see researchers present their findings, alongside outreach events involving schools, artists, industry, and the public.

As we continue to explore the mysteries of the universe, this research serves as a testament to the importance of continued investment in cosmological studies and the pursuit of knowledge. The unveiling of these hidden satellites offers a glimpse into the intricate web of galaxy formation and evolution, leaving us with new questions and avenues for investigation.