X-Ray 'Mirror' Effect Changes How We Measure Stars

By Space.Fan Editorial DeskSeptember 28, 2026 at 11:01 PM UTC

Scientists found that light bouncing off a star's material makes it look much heavier than it actually is.

Image · Space.Fan

The Drop

A symbiotic named V648 Car is putting on a strange light show. Scientists have known for a while that this system sends out strong X-rays, but they recently took a closer look using NASA's Nu telescope and the Swift observatory. By combining data from these two powerful space tools, the researchers discovered that a large amount of the X-ray light they see is actually a reflection. Think of it like standing in a room with many mirrors. If you look at the walls, you might think there are more people in the room than there really are because you are seeing reflections of the same person over and over. In the case of V648 Car, gas swirling around the acts like a mirror for X-rays. This 'Compton reflection' accounts for more than one-third of the light being picked up by our telescopes. When astronomers looked at the data without accounting for these reflections, they made mistakes about the 's properties. Because the reflection makes the X-rays look more intense, previous math suggested the was much hotter and heavier than it is. By including the reflection in their new computer models, the team found the is actually about 20 percent lighter than what they had calculated before.

Why It Matters

This discovery matters because it helps astronomers get more accurate measurements of s across the galaxy. If we ignore how light bounces off surrounding space material, we end up with the wrong numbers for mass and temperature. By correctly accounting for this reflection, scientists can now refine how they weigh and measure similar s, leading to a better understanding of how these cosmic systems evolve over time.

The Catch

While the reflection model fits the data much better than previous ones, it is not a perfect picture. The amount of light bouncing around is quite high, which suggests that the setup is more complex than a simple light source shining onto a flat disk. The researchers proposed that multiple layers of reflection might be happening, but they still need to perform more studies to prove exactly how the light is moving through the gas.

Put That in Perspective

In the past, scientists often assumed that the X-rays they saw came directly from the star. Now that they know reflection plays such a huge role in V648 Car, they will likely go back and look at other similar binary star systems to see if they have been miscalculating their weights for years.

Source September 28, 2026

Jhérssica Freitas, Raimundo Lopes de Oliveira, Koji Mukai

Universidade Federal de Sergipe, Observatório Nacional, NASA/GSFC, University of Maryland Baltimore County·The Astrophysical Journal·10.3847/1538-4357/ae939a

Keep Exploring Space

$Large fractured asteroid engulfed in flames and glowing debris as it travels through space.$

Universe

How Newborn Neutron Stars Launch Massive Space Jets

Super-powered magnetic stars may launch the fastest beams in the universe right after they are born.

SIMULATION3 HR AGO

James Webb Space Telescope in space with its gold segmented mirror facing the stars.

Universe

New Software Makes Space Simulations Faster and More Powerful

Researchers created a faster way for supercomputers to map how light helped shape the early universe.

PEER REVIEWED3 HR AGO

Huge twisting prominence of glowing plasma erupting above the surface of the Sun.

Sun & Space Weather

Tiny Storms Keep a Young Star Glowing in Radio Light

Scientists found that constant, miniature star flares are likely what power the steady radio glow of the active star AU Mic.

PEER REVIEWED3 HR AGO

Colorful glowing nebula filled with stars and clouds of blue, purple, orange, and red gas.

Images

A New Look at the Glowing Shrimp Nebula

Astronomers have captured a stunning view of Sh2-188, a cosmic cloud that looks surprisingly like a shrimp swimming through space.

NEW OBSERVATION12 HR AGO