Researchers from NYU Abu Dhabi's (NYUAD) Center for Space Science have
discovered a new set of waves in the sun that, unexpectedly, appear to
travel much faster than predicted by theory.
In the study "Discovery of high-frequency-retrograde vorticity waves in the
sun," published in the journal Nature Astronomy, the researchers—led by
Research Associate Chris S. Hanson—detailed how they analyzed 25 years of
space and ground-based data to detect these waves. The high-frequency
retrograde (HFR) waves, which move in the opposite direction of the sun's
rotation, appear as a pattern of vortices (swirling motions) on the surface
of the sun and move at three times the speed established by current theory.
The interior of the sun and stars cannot be imaged by conventional astronomy
(e.g. optical, X-ray etc.), and scientists rely on interpreting the surface
signatures of a variety of waves to image the interiors. These new HFR waves
may yet be an important puzzle piece in our understanding of stars.
Complex interactions between other well known waves and magnetism, gravity
or convection could drive the HFR waves at this speed. "If the HFR waves
could be attributed to any of these three processes, then the finding would
have answered some open questions we still have about the sun," said Hanson.
"However, these new waves don't appear to be a result of these processes,
and that's exciting because it leads to a whole new set of questions."
This research was conducted within NYUAD's Center for Space Science in
collaboration with the Tata Institute of Fundamental Research (TIFR) and New
York University, using NYUAD and TIFR's computational resources. By studying
the sun's interior dynamics through the use of waves scientists can better
appreciate the sun's potential impact on the Earth and other planets in our
solar system.
"The very existence of HFR modes and their origin is a true mystery and may
allude to exciting physics at play," said Shravan Hanasoge, a co-author of
the paper. "It has the potential to shed insight on the otherwise
unobservable interior of the sun."
Reference:
Shravan Hanasoge, Discovery of high-frequency retrograde vorticity waves in
the Sun, Nature Astronomy (2022).
DOI: 10.1038/s41550-022-01632-z.
Tags:
Space & Astrophysics