Active Stars That Mimic Black Holes

By Space.Fan Editorial DeskSeptember 24, 2026 at 5:03 PM UTC

Some stars act so much like black holes that astronomers can barely tell them apart.

The Drop

Scientists have found a group of s that are acting like imposters in space. These s are called RS Canum Venaticorum binaries. A binary system is two s orbiting each other. Because these s spin so fast and have strong magnetic fields, they create powerful radio signals that travel across the galaxy. Astronomers used giant radio telescopes, like those used for the VLASS and RACS surveys, to look for these signals. They spotted 108 systems that give off these radio waves. By checking records from X-ray space telescopes, the researchers found that these s are very bright in both radio and X-ray light. This makes them look almost exactly like the way a looks when it is sitting quietly in space. Because the light looks so similar, it is very easy for scientists to mix up a normal, active system with a .

Why It Matters

This discovery is important because it changes how we classify objects in space. If we see a bright radio signal, we usually think it might be a feeding on nearby material. Now we know that some s can create signals that are just as strong. This helps astronomers avoid making mistakes when they catalog objects in the deep sky.

The Catch

While these s act like s, they are not the same. We do not fully know why some of these s are so much louder in radio waves than others. Most large, bright s are actually quite quiet, so finding the two that are exceptionally loud was a surprise. More study is needed to understand the specific magnetic conditions that cause these s to beam out so much energy.

Put That in Perspective

In the past, astronomers had fewer tools to map the entire sky. With new, massive surveys like VLASS and RACS, we can look at thousands of stars at once. Researchers will likely look closer at these stars to see if their radio signals change over long periods of time, helping us learn more about how star magnetic fields work.

Source September 24, 2026

ApJ