Astrophysicists have discovered a new type of wave on the Sun that propagates against the direction of the star’s rotation at high speed. Observational data refute all three possible theories that could explain the nature of such waves. The results of the study are published in Nature Astronomy.
Scientists from New York University in Abu Dhabi analyzed 25 years of data from space and ground-based telescopes that observe the sun. As a result of the study, high-frequency waves were discovered that propagate in the direction opposite to the rotation of the star.
“For decades, theorists have assumed the existence of solar inertial waves, which are hydrodynamic waves found in rotating fluid bodies,” says Chris Hanson, co-author of the study. — On Earth, inertial waves play an important role in shaping the weather. For example, they push cold polar air out of the Arctic into North America.”
The found inertial waves appear as eddies on the surface of the Sun and move at a speed three times faster than Rossby waves (the most famous inertial waves that occur in rotating fluids). Scientists note that Rossby waves move at the highest possible speed, explained by hydrodynamics.
The researchers suggested that such an increase in the speed of the waves they found could be caused by the influence of a magnetic field, gravity or convection currents. However, the results of modeling the impact of these factors contradict the data obtained by observing the Sun. Thus, the nature of new waves remains a mystery to scientists.
“We have yet to determine the source of these waves, since they, apparently, cannot be explained only by hydrodynamics and the influence of additional factors on it,” says Hanson. “The uncertain nature of these waves promises us the creation of new physics and a fresh look at the processes occurring inside the Sun and other stars.”