According to a study by the National Center for Atmospheric Research (NCAR), many coronal loops – rope filaments of plasma that exist in the Sun’s atmosphere – may actually be optical illusions. This discovery challenges what we already know about the Sun.

“We know that developing such methods will be an extremely difficult task, but our study demonstrates that the way we currently use when observing the Sun is not enough to truly understand the physics of our star,” Malanushenko said.

The results, which the research team calls the coronal curtain hypothesis, are important for observations of the Sun, as hypothesized coronal loops have been used for decades to provide information about the density, temperature, and other physical characteristics of the solar atmosphere.

“I have devoted my entire career to studying coronal loops,” said Anna Malanushenko, an NCAR staffer who led the study. “I was excited because the simulation provided the opportunity to study the loops in more detail. But I did not expect such results. This is a completely new paradigm for understanding the Sun’s atmosphere.”

The MURaM simulation is one of the most realistic images of the solar corona ever created, but it’s still just a model. Analyzing how many coronal loops are actually optical illusions will require carefully calibrated observation methods.

“We know that developing such methods will be an extremely difficult task, but our study demonstrates that the way we currently use when observing the Sun is not enough to truly understand the physics of our star,” Malanushenko said.